1&iFORҥLKyDFKҩWÿѭӧc sӱGөQJWURQJNKyDOXұQ
7rQKyDFKҩt &{QJWKӭFKyDKӑc Nguӗn gӕc Ĉӝ tinh khiӃt
Nitric acid HNO3 Xilong Chemical,
.DOLKLÿUR[LW KOH Xilong Chemical,
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&iFGөQJFөÿѭӧc sӱGөQJEDRJӗm: cӕFQXQJPOSLSHWPOEuQK ÿӏQKPӭFPOEHFKHUPOӕQJÿRQJ ml)
ThiӃt bӏ WKtQJKLӋm bao gӗm: &kQÿLӋn tӱKmQJ2KDXVPi\NKXҩ\WӯKmQJ 9HOSEuQKWKӫy nhiӋWGXQJWtFKPOPi\ÿiQKVLrXkPKmQJ*WVRQLFPi\O\ WkPKmQJ0HPPHUWWӫVҩ\KmQJ0HPPHUWWӫQXQJKmQJ&DUERULWHPi\ÿR89 9LVKmQJ7KHUPRĈqQ/('KmQJ2(0
3KѭѫQJSKiSWKӫy nhiӋWÿѭӧc sӱ dөQJÿӇ tәng hӧp BiVO44XiWUunh tәng hӧp bao gӗm FiF Eѭӟc sau: 0.02 mol Bi(NO3)3ā+22ÿѭѫFKzDWDQWURQJP/GXQJGӏch HNO3NêKLӋXOjGXQJGӏch A Dung dӏch thӭ KDLÿѭӧFÿLӅu chӃ bҵQJFiFKKzDWDQ0.02 mol NH4VO3 KzDWDQ YjR0 mL dung dӏFK1D2+0NêKLӋXOjGXQJGӏch B 6DXÿynhӓ tӯ tӯ dung dӏFK%YjRGөng dӏch A YjNKXҩ\OLrQWөc bҵQJPi\NKXҩy tӯ, NêKLӋXOjGXQJGLFK$% TiӃp theo, bә sung 30 mL dung dӏFK1D2+0YjRGXQJ dӏFK$%YjNKXҩ\OLrQWөFWURQJYzQJJLӡ Hӛn hӧp WKXÿѭӧFFyPjXYjQJ ÿѭӧc FKRYjRӕQJ7HOIORQFyEӑc bҵQJWKpSNK{QJJӍ Yjÿѭӧc gia nhiӋt vӟLFiF nhiӋWÿӝ NKiFQKDX o C, 120 o C, 140 o C 160 o C, 180 o C, 200 o C ,thӡi gian 48KYjNK{QJJLD nhiӋt Hӛn hӧp sau thӫy nhiӋWÿѭӧc lӑc rӱa bҵQJQѭӟc cҩt nhiӅu lҫQYjVҩ\NK{TXD ÿrPӣ 60 o C Chҩt bӝWPjXYjQJWKXÿѭӧc sau sҩ\NK{ÿѭӧc nung ӣ 300 o C trong 3h [56]
Lu̵QYăQWK̩FVƭ CBHD: TS Nguy͍n Duy Trinh
Lu̵QYăQWK̩FVƭ CBHD: TS Nguy͍n Duy Trinh
Tәng hӧp vұt liӋu NiFe2O4 bҵQJSKѭѫQJSKiSWKӫy nhiӋW4XiWUuQKWәng hӧp bao gӗPFiFEѭӟc sau:
%ѭӟc 1: 4mmol Fe(NO3)3.9H2O Yj PPRONiCl2ā+2O ÿѭӑF KzDtan trong P/Qѭӟc cҩWNêKLӋXOjGXQJGӏch A);
%ѭӟF7KrPP/FӫD.2+0YjRGXQJGӏFK$YjNKXҩ\OLrQWөc trong YzQJK
%ѭӟc 3: Hӛn hӧSÿѭӧFFKRYjRӕQJ7HOIORQFyEӑc bҵQJWKpS NK{QJ JӍ Yj ÿѭӧc thӫy nhiӋt ӣ FiFQKLӋWÿӝ 16&WURQJK
%ѭӟc 4: Hӛn hӧp sau thӫy nhiӋWÿѭӧc lӑc rӱa bҵQJQѭӟc cҩWYjHWDQROWX\Ӌt ÿӕi nhiӅu lҫn, sҩy ӣ &WURQJJLӡ trong tӫ FKkQNK{QJÿӇ WKXÿѭӧc bӝt NiFe2O4
Lu̵QYăQWK̩FVƭ CBHD: TS Nguy͍n Duy Trinh
+uQK.2 4X\WUuQKWәng hӧp vұt liӋu NiFe2O4 bҵQJSKѭѫQJSKiSWKӫy nhiӋt
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Tәng hӧp vұt liӋu tӯ WtQK[NiFe2O4/BiVO4 WURQJÿy[OjWӹ lӋ khӕLOѭӧng cӫa NiFe2O4/BiVO4 Yj ÿѭӧc chӑQ Oj Yj ÿѭӧc tәng hӧp bҵng SKѭѫQJSKiSWKӫy nhiӋW4XiWUuQKWәng hӧp bao gӗPFiFEѭӟc sau:
%ѭӟc 1: 4mmol Bi(NO3)3.5H2O ÿѭӑFKzDWDQWURQJP/GXQJGӏch HNO3
%ѭӟc 2: 4mmol NH4VO3 ÿѭӧFKzDWDQWURQJP/Qѭӟc sDXÿyNKXҩ\OLrQWөc trong 1 giӡ WKXÿѭӧc dung dӏch trong suӕWNêKLӋXOjGXQJGӏch B);
%ѭӟc 3: TiӃp theo, nhӓ tӯ tӯ dung dӏFK%YjR$YjNKXҩy tҥRWKjQKKX\ӇQSK PjXYjQJNêKLӋXOjGXQJGӏch AB);
%ѭӟc 4: MӝWOѭӧng nhҩWÿӏnh NiFe2O4 ÿѭӧc tәng hӧSQKѭ P{Wҧ ӣ WUrQÿѭӧc SKkQWiQYjRWURQJGXQJGӏch AB vӟi sӵ khuҩy mҥQKOLrQWөFWURQJSK~W
%ѭӟc 5: Sau khi khuҩ\SK~WKӛn hӧSÿѭӧFFKRYjRӕQJ7HOIORQFyEӑc bҵQJWKpSNK{QJJӍ Yjÿѭӧc thӫy nhiӋt ӣ FiFQKLӋWÿӝ &WURQJK
%ѭӟc 6: Hӛn hӧp sau thӫy nhiӋWÿѭӧc lӑc rӱa bҵQJQѭӟc cҩWYjHWDQROWX\Ӌt ÿӕi nhiӅu lҫn, sҩy ӣ &WURQJJLӡ trong tӫ FKkQNK{QJ
%ѭӟc 7: BӝWWKXÿѭӧFÿѭӧc nung ӣ &WURQJJLӡ [48]
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+uQK.3 4X\WUuQKWәng hӧp vұt liӋu NiFe2O4/BiVO4 bҵQJSKѭѫQJSKiSWKӫy nhiӋt
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Vұt liӋX FRPSRVLWH [~F WiF TXDQJ KyDNiFe2O4/BiVO4 hoһc NiFe2O4 Yj BiVO4 ÿѭӧc sӱ dөQJÿӇ khҧRViWKRҥWWtQKTXDQJ[~FWiFSKkQKӫy chҩWPjXKӳXFѫ ÿӝc hҥL 7URQJ EiR FiR OXұQ YăQ Qj\ FKҩW PjX KӳX Fѫ ÿLӇQ KuQK ÿѭӧc chӑQ Oj Rhodamine B (RhB) Yj&U\VWDO9LROHW&9 ÿѭӧc tiӃQKjQKQJKLrQFӭX7URQJÿy nguӗQiQKViQJQKuQWKҩ\ÿѭӧc sӱ dөQJOjÿqQ/('FyF{QJVXҩt 60W
4XiWUuQKÿiQKJLiKRҥWWtQK[~FWiFTXDQJKyDFӫa vұt liӋu BiVO4 ÿѭӧc gӗm FiFEѭӟc sau:
%ѭӟc 1: 0.05g mүX[~FWiF00 mL dung dӏch (CV) vӟi nӗQJÿӝ [~FWiF WѭѫQJӭQJOj20 ppm
%ѭӟc 2: Dung dӏFKÿѭӧc khuҩy tӯ trong tӕLSK~WYjOҩy mүu dung dӏch 60 SK~WOҫn
%ѭӟc 3: ChiӃXÿqQYjOҩy mүu theo thӡLJLDQQKѭÿѭӧFWUuQKEj\ӣ Bҧng 2.1
%ѭӟF&iFPүu sau khi lҩ\ÿѭӧFO\WkPYzQJSK~WWURQJSK~W
%ѭӟc 5: CuӕLFQJQӗQJÿӝ chҩWPjXÿѭӧFÿRWUrQPi\89-vis lӓng ӣ Eѭӟc VyQJȜ 580nm
4XiWUuQKÿiQKJLiKRҥWWtQK[~FWiFTXDQJKyDFӫa vұt liӋu tәng hӧSÿѭӧc gӗm FiFEѭӟc sau:
%ѭӟc 1: 0.2g mүX [~F WiF P/ GXQJ Gӏch (RhB) vӟi nӗQJ ÿӝ [~F WiF WѭѫQJӭQJOj -5 M
%ѭӟc 2: Dung dӏFKÿѭӧF[iRWUӝn bҵQJPi\EѫPFKuPWURQJWӕi 60 ph~WYj lҩy mүu dung dӏFKSK~WOҫn
%ѭӟc 3: ChiӃXÿqQYjOҩy mүu theo thӡLJLDQQKѭÿѭӧFWUuQKEj\ӣ Bҧng 2.1
%ѭӟF&iFPүu sau khi lҩ\ÿѭӧFO\WkPYzQJSK~WWURQJSK~W
%ѭӟc 5: CuӕLFQJQӗQJÿӝ chҩWPjXÿѭӧFÿRWUrQPi\89-vis lӓng ӣ Eѭӟc VyQJȜ nm
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Bҧng 3.2 Thӡi gian lҩy mүXWURQJÿiQKJLiKRҥWWtQKTXDQJ[~FWiF
Dung dӏch ĈLӅu kiӋn thӡLJLDQSK~W
3.4 3KѭѫQJSKiSÿiQKJLiFҩXWU~FYұt liӋu
33KѭѫQJSKiSQKLӉu xҥ tia X (X-ray diffraction, XRD)
3KpSÿRJLҧQÿӗ nhiӉu xҥ tia X (X-UD\GLIIUDFWLRQ;5'ÿѭӧF[ky dӵng dӵa WUrQQJX\rQOtFӫa hiӋQWѭӧng nhiӉu xҥ WUrQWLQKWKӇ GiҧQÿӗ ;5'ÿѭӧFGQJÿӇ SKkQ WtFKFiFSKDFҩXWU~FWLQKWKӇ Yj[iFÿӏQKWK{QJWLQYӅ tinh thӇ hӑc cӫa vұt liӋu kӃt tinh Tӯ sӕ liӋu giҧQÿӗ ;5'VDXNKLÿӕi chiӃu vӟLWKҿFKXҭn JPCDS trong nJkQKjQJ dӳ liӋX,&''WDFyWKӇ [iFÿӏQKÿѭӧc hҵng sӕ mҥng tinh thӇ NhӳQJÿһFWUѭQJTXDQ trӑng nhҩt tӯ giҧQÿӗ ;5'OjYӏ WUtFiFYҥch nhiӉu xҥFѭӡQJÿӝ FiFYҥch nhiӉu xҥ Yj KuQKGҥng cӫDÿѭӡQJFRQJSKkQEӕ FiFYҥch nhiӉu xҥ ÿy[57] Tӯ mӕLOLrQKӋ giӳa GKNOYjFiFKҵng sӕ mҥng cӫa tӯng loҥi hӋ cҩXWU~FWLQKWKӇ WDFyWKӇ [iFÿӏQKÿѭӧc mӝWFiFKFKtQK[iFKҵng sӕ mҥng cӫa tinh thӇ ÿy'ӵDYjRYӏ WUtFӵFÿҥi nhiӉu xҥ Fy thӇ WtQKÿѭӧFNtFKWKѭӟc tinh thӇ WKHRF{QJWKӭc Debye Scherrer: ݀ ൌ Ǥ ɉ ȾǤ ߠ
3KѭѫQJSKiSQKLӉu xҥ ;;5'ÿѭӧc sӱ dөQJÿӇ QJKLrQFӭu cҩXWU~FYjWKjQK phҫn pha cӫa vұt liӋu BiVO4 DӵDWUrQNӃt quҧ SKkQWtFK;5'FyWKӇ [iFÿӏQKWKjQK phҫQSKDPRQRFOLQLFYjWHWUDJRQDOWK{QJTXDYLӋFVRViQKJLҧQÿӗ XRD cӫa vұt liӋu BiVO4 ÿѭӧc tәng hӧp so vӟi giҧQÿӗ BiVO4 chuҭQWKHR-3&'6&yWKӇ [iFÿӏQKÿѭӧc FiFWK{QJVӕ mҥng tinh thӇ cӫa vұt liӋu BiVO4 dӵDYjRVӕ liӋu cӫa giҧQÿӗ;5'
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7URQJEjLOXұQYăQQj\GӵDWUrQNӃt quҧ SKkQWtFK;5'FyWKӇ [iFÿӏQKWKjQKSKҫn pha monoclinLFYjWHWUDJRQDOWK{QJTXDYLӋFVRViQKJLҧQÿӗ XRD cӫDYұWOLӋu BiVO4 ÿѭӧc tәng hӧp vӟi giҧQÿӗ BiVO4FKXҭQWKHR-3&'6+uQK3.4 thӇ hiӋn phә XRD cӫDFҩXWU~FV-m BiVO4 Yj]-t BiVO4.[57]
+uQK.4 Phә XRD cӫDFҭXWU~FV-m BiVO4 Yj]-t BiVO4
3KѭѫQJSKiSQj\ÿѭӧc sӱ dөQJÿӇ QJKLrQFӭXKuQKWKiLEӅ mһWNtFKWKѭӟFYj FҩXWU~FKҥWFӫDFiFPүu vӟLÿӝ SKkQJLҧLFDR1JX\rQWҳFFKөSҧQK6(0ÿѭӧFP{ tҧ ӣ+uQK3.5
&KPÿLӋn tӱ VDXNKLÿLTXDKӋWKҩXNtQKWӯ hӝLWөYjFXӝQTXpWÿLӋn tӱVӁ ÿӵѫFKӝLWөOrQEӅ mһt mүu cҫQQJKLrQFӭX1Kӡ cuӝQTXpWFKPWLDÿLӋn tӱVӁTXpWWUrQEӅ mһt mүXNKLWѭѫQJWiFYӟLFiFQJX\rQWӱ WUrQEӅ mһt mүXVӁOjPSKiW[ҥÿLӋn tӱWKӭFҩSYjÿLӋn tӱWiQ[ҥQJѭӧc HiӋXVXҩWSKiW[ҥFiFÿLӋn tӱWKӭFҩSSKөWKXӝc YjREӅ mһt cӫa mүXWҥLYӏWUtSKiW[ҥSKiW[ҥPҥQKӣ chӛ mһt mүu lӗLSKiW[ҥ\Ӄu ӣ chӛ mһt mүXO}PĈҫXWKXWtQKLӋXÿѭӧc bӕ WUtÿӇ WKXFiFÿLӋn tӱWKӭFҩSVDXÿyWtQ hiӋXÿѭӧc khuӃFKÿҥLYjKLӇn thӏWUrQPjQKuQK.KLFKPÿLӋn tӱ tӟLTXpWWUrQEӅ mһt mүXWKuWtQKLӋXWKXÿѭӧc tӯ FiFÿLӋn tӱWKӭFҩSÿѭӧFÿӗng bӝYjTXpWWUrQPjQKuQKKLӇn thӏ, mӛLÿLӇPWUrQPүXVӁWѭѫQJӭQJYӟi mӝWÿLӇm ViQJWUrQPjQKuQKKLӇn thӏ KӃt quҧ OjFKPÿLӋn tӱ TXpWWUrQPүXÿӃn chӛQjRSKiW[ҥPҥQKÿLӋn tӱWKuWtQ
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3*676%L;XkQ7KjQK hiӋXWѭѫQJӭQJWUrQPjQKuQKVӁViQJPҥQKYjQJѭӧFOҥLFKӛ QjRWUrQPүXSKiW[ҥ yӃXWKuWtQKLӋXWѭѫQJӭQJWUrQPjQKuQKKLӇn thӏ OjVing yӃX1KѭYұ\ҧQKWKXÿѭӧF WUrQPjQKuQKKLӇn thӏVӁSKҧQiQKKuQKWKiLEӅ mһt cӫa mүXQJKLrQFӭX[58]
+uQK.5 6ѫÿӗ QJX\rQWҳFVLQKUDFiFWtQKLӋu trong SEM 3.4.3 3KѭѫQJSKiSSKә phҧn xҥ khuӃFKWiQWӱ ngoҥi khҧ biӃn (UV-Vis DRS)
Phә phҧn xҥ khuӃFKWiQQҵm ӣ YQJNKҧ kiӃQKD\YQJWӱ ngoҥLFzQJӑLOj phә phҧn xҥ khuӃFK WiQ Wӱ ngoҥi khҧ kiӃn (UV-Visible Diffuse Reflectance Spectroscopy, UV-Vis-'56Ĉӕi vӟi vұt liӋu hҩp thө iQKViQJNKLGzQJWLDWӟLFy FѭӡQJÿӝ (Io) chiӃXYjRYұt liӋu hҩp thө qua mӝt lӟp mӓQJFyÿӝ Gj\OjOYӟi hӋ sӕ hҩp thө İ&ѭӡQJÿӝ (I) cӫDWLDOyÿѭӧFWtQKWKHRÿӏnh luұt hҩp thө Lambert-Bee r [59]:
Sӵ hҩp thө iQKViQJOLrQTXDQÿӃn sӵ chuyӇn dӏFKÿLӋn tӱ1ăQJOѭӧng hҩp thө chuyӇn dӏFKÿLӋn tӱ FyWKӇ WtQKWRiQGӵDYjRSKѭѫQJWUuQK7DXFWK{QJTXDKӋ sӕ hҩp thө Į+Ӌ sӕ hҩp thө ĮÿѭӧFWtQKQKѭVDX
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7URQJÿyOOjFKLӅXGj\Fӫa mүXÿR7Ojÿӝ truyӅQTXDÿѭӧFWtQKWӯ phә UV- VisDRS ĮKY 2 = A (hv-Eg) 1/2 (2.3)
3KѭѫQJ WUuQK ÿѭӧc gӑL Oj SKѭѫQJ WUuQK 7DXF WURQJ ÿy K Oj Kҵng sӕ 3ODQFN&OjKҵng sӕ, Eg OjQăQJOѭӧng hҩp thө chuyӇn dӏFKÿLӋn tӱ Yjݒ OjWҫn sӕ NtFK WKtFK9Ӂ ÿӗ thӏ ĮKY 2 theo hvÿѭӡng thҷng tuyӃQWtQKÿLTXDÿLӇm uӕn cӫDÿѭӡng FRQJQj\Fҳt trөFKRjQKJLiWUӏ KRjQKÿӝ ӣ ÿLӇm cҳWFKtQKEҵQJQăQJOѭӧng hҩp thө chuyӇn dӏFKÿLӋn tӱ
3KѭѫQJSKiSQj\JL~S[iFÿӏnh vi cҩXWU~FFӫa vұt liӋXÿһc biӋWOj[iFÿӏnh sӵ hiӋn diӋn cӫDFiFQKyPFKӭFYjSKDFyWURQJYұt liӋX7URQJÿӅ WjLQj\SKә Raman ÿѭӧFÿRWUrQKӋ phә kӃ Raman cӫDKmQJ+25,%$-RELQ 140 Ƞ &YѭӧWTXDÿLӇPKyDÿөFNpRWKHRÿyOjTXiWUuQKED\KѫLQѭӟc mҥnh Yjkeo tө chҩt hoҥWÿӝng bӅ mһt dүQÿӃn sӵ WKD\ÿәi cӫa WKjQKSKҫQJHOYjFҩXWU~F GRÿyNKyKuQKWKjQKYұt liӋXFyFҩXWU~FFyÿӝ trұt tӵ cao QrQGLӋQWtFKEӅ mһWYjNtFKWKѭӟc mao quҧQÿӅu giҧPÿHPOҥi hiӋu suҩt xӱ OêJLҧm, ÿӗng thӡLNKLWăQJQKLӋWÿӝ FNJQJOjPWăQJQăQJOѭӧng chuyӇQÿӝng Brown dүQÿӃn khҧ QăQJWӵ tә hӧp cӫa hӧp chҩWOjPWăQJFKLӅXGjLFӫa chuӛi kӷ QѭӟFOj\Ӄu tӕ quyӃt ÿӏQKÿӃQNtFKWKѭӟc mao quҧn cӫa vұt liӋu
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+uQK.7 HoҥWWtQKTXDQJ[~FWiFFӫDFiFPүXWURQJSKkQKӫy CV
BiӇXÿӗ EiQ ORRJDULWKyDFӫa nӗQJÿӝ EDQÿҫu so vӟi thӡi gian chiӃu xҥ Oj tuyӃQWtQKELӇu thӏ ÿӝng hӑc bұc mӝt 7KtQJKLӋPÿѭӧc lһp lҥi vӟLFiFPүu vұt liӋu NKiFQKDXWҥi nӗQJÿӝ 20 ppm vӟi thӡLJLDQSK~W7ӕFÿӝ EDQÿҫu cho mӛi mүu vұt liӋXÿѭӧF[iFÿӏnh tӯ hҵng sӕ tӕFÿӝ bұc mӝWYjQӗQJÿӝ EDQÿҫu Dӳ liӋXVDXÿy ÿѭӧFÿѭDYjRP{KuQKWӕFÿӝ ÿӝng hӑc Langmuir ± +LQVKHOZRRGÿmÿѭӧFiSGөng cho tӕFÿӝ SKiKӫ\TXDQJ[~FWiFEDQÿҫu cӫa nhiӅu hӧp chҩt hӳXFѫÿѭӧFP{Wҧ theo F{QJWKӭc [72]:
7URQJÿy&OjQӗQJÿӝ tҥi thӡLÿLӇPW&ROjQӗQJÿӝ EDQÿҫXNOjKҵng sӕ tӕc ÿӝ phҧn ӭng
4XDÿyÿѭӡng biӇu diӉn ln(CȠ/C) theo thӡLJLDQOjÿѭӡng thҷQJYjKӋ sӕ JyF FKtQKOjKҵng sӕ tӕFÿӝ biӇu diӉQNSK~W -1 ÿѭӧc thӇ hiӋQTXDKuQK.8A YjÿѭӧFWyP tҳt trong bҧng 4.5 Mүu BVO_140 vӟi hҵng sӕ tӕFÿӝ k = 11.36 x10 -3 SK~W -1 FDRKѫQ
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3*676%L;XkQ7KjQK so vӟLFiFPүXFzQOҥLYjKӋ sӕ WѭѫQJTXDQJ5 2 = 0.97936 Sӵ SKkQKӫy nӗQJÿӝ CV ÿӕi vӟi mүu BVO_140 ÿmÿѭӧFTXDQViWWKrPTXDELӇXÿӗ hҩSWKXÿREҵQJPi\89- Vis vӟLEѭӟFVyQJWӯ Ȝ BQPYjFѭӡQJÿӝ hҩp thө tҥLÿӍnh hҩp thө cӵFÿҥi ȜFӵFÿҥi = 580nm) giҧm dҫn cho thҩy sӵ suy giҧm tӯQJEѭӟc cӫa CV ÿѭӧc thӇ hiӋn TXDKuQK.8B
+uQK.9 Phә hҩp thu UV-Vis trong CV cӫa mүu vұt liӋu BVO_140
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+uQK.10 0jXVDXNKL[ӱ OêFӫa mүu vұt liӋu BVO_140
Bҧng 4.6 Bҧng thӕQJNrKҵng sӕ tӕc ÿӝ NYjKӋ sӕ WѭѫQJTXDQR 2
4.3.2 KӃt quҧ khҧo ViWQӗQJÿӝ cӫa dung dӏch Crytal Violet
KhҧRViWҧQKKѭӣng cӫa nӗQJÿӝ ÿӃn hiӋu quҧ [~FWiFTXDQJEҵng viӋc thay ÿәi nӗQJÿӝ &9EDQÿҫu (5, 10, 20, 30, 40SSPYjYүn giӳ QJX\rQOѭӧng chҩW[~FWiF OjJYӟi thӡi gian chiӃXViQJOjJLӡ +uQK.11 WUuQKEj\ҧQKKѭӣng cӫa nӗng ÿӝ WUrQKLӋu quҧ loҥi bӓ PjXFU\WDOYLROHWVӱ dөng vұt liӋu BVO_140 Sӵ SKkQKӫy QKDQKFKyQJFӫDPjXFU\WDOYLROHWOrQWUrQYұt liӋu BVO_140 ÿѭӧFTXDQViWWURQJ YzQJ60 SK~W chiӃXViQJ Cho thӡi gian tiӃS[~FGjLKѫQSKҫQWUăPSKkQKӫy thay ÿәLNK{QJÿiQJNӇ tҥi nӗQJÿӝ PjXcrytal violet EDQÿҫu cӫDSSPSSPYjSSP
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DӵDWKHRÿyVӵ SKkQKӫy tӕi da cӫDPjXcrytal violet WKuÿҥWÿѭӧc tҥi 90% cho 20ppm Yj>90FKRSSPYj0ppm Khi nӗQJÿӝ WăQJOrQSSPYj0ppm, phҫQWUăP SKkQKӫy giҧPÿӃn khoҧng 42% tҥi 40ppm, 62% tҥi 30ppm Cho thҩy rҵng tӕFÿӝ SKkQKӫ\TXDQJKyDOLrQTXDQÿӃn sӵ KuQKWKjQKJӕc x 2+WUrQEӅ mһt chҩW[~FWiFYj khҧ QăQJSKҧn ӭng giӳa gӕc x OH vӟi chҩWPjX1ӗQJÿӝ &9EDQÿҫXWăQJNpRWKHR mӝWOѭӧng lӟn CV hҩp phө WUrQFiFWkPKRҥWÿӝng bӅ mһt cӫa chҩW[~FWiFGRÿyVӵ hҩp phө cӫDFiFion hydroxyl (OH - WUrQFQJVӕ WkPKӑaWÿӝQJQj\JLҧmQJKƭDOj tӕFÿӝ KuQKWKjQKFiFJӕc x 2+WiFQKkQR[LKyDFKtQKFҫn thiӃt cho viӋFJLDWăQJKLӋu suҩWSKkQKӫy quang giҧPWKHR7KHRÿӏnh luұt Beer-Lambert, khi nӗng ÿӝ chҩWPjX WăQJFKLӅXGjLÿѭӡng dүQFiFSKRWRQYjRWURQJGXQJGӏch giҧPYjFiFSKRWRQFyWKӇ bӏ chҳQWUѭӟc khi tiӃQÿӃn bӅ mһW[~FWiFGRÿyVӵ hҩp thө photon cӫa chҩW[~FWiF giҧPÿLGүQÿӃn sӵ SKkQKӫ\TXDQJKyDJLҧm [73][74][75]
+uQK.11 KӃt quҧ khҧRViWQӗQJÿӝ cӫa dung dӏch Crytal Violet cӫa mүu
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4.3.3 KӃt quҧ khҧRViWKjPOѭӧng vұt liӋu [~FWiF
KhҧRViWҧQKKѭӣng cӫa KjP Oѭӧng vұt liӋX[~FWiF ÿӃn hiӋu quҧ [~FWiFTXDQJ bҵng viӋFWKD\ÿәi KjPOѭӧng chҩW[~FWiF (30, 40, 50, 60, 70mg) tҥi nӗQJÿӝ CV NK{QJÿәLOjSSPÿѭӧFWUuQKEj\WURQJKuQK.12 PhҫQWUăPSKkQKӫy WăQJWӯ 80% ÿӃn 99% cӫa PjXcrystal YLROHWWѭѫQJӭng vӟLOѭӧng chҩt [~FWiF WăQJWӯ 30mg g/l ÿӃn 70mJOĈLӅXQj\FKRWKҩ\Oѭӧng chҩt [~FWiF FjQJWăQJWKuSKҫQWUăPORҥi bӓ FjQJFDRSӵ JLDWăQJKLӋu suҩWSKkQKӫy cӫa thuӕc nhuӝPFyWKӇ ÿѭӧFFKROjGRVӵ sҹQFyFӫDFiFOӛ trӕng quang sinh nhiӅXKѫQÿѭӧc cung cҩp bӣLKjPOѭӧng chҩW[~F WiF FDRKѫQ
+uQK.12 KӃt quҧ khҧRViWNKӕLOѭӧng vұt liӋX[~FWiF cӫa mүu BVO_140 4.4 KӃt quҧ ÿiQKJLiKRҥWWtQKTXDQJKyDFӫa vұt liӋXFRPSRVLWHWUrQQӅn BiVO 4
Trong luұQYăQQj\QJKLrQFӭu hiӋu suҩWTXDQJ[~FWiFFӫa vұt liӋu tәng hӧp NiFe2O4/BiVO4 FQJYӟi NiFe2O4 Yj%L924 WK{QJTXDVӵ SKkQKӫ\TXDQJ5K%Gѭӟi chiӃu xҥ iQKViQJ/('ÿѭӧc thӇ hiӋQWURQJKuQK
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+uQK.13 HoҥWWtQK[~FWiFFӫa vұt liӋu nano NiFe2O4, BiVO4 Yj1iFe2O4/BiVO4
Sӵ suy giҧPÿӝng hӑFOQ&Ƞ&WKHRP{KuQKÿӝng hӑc bұc mӝt (A), phә hҩp thu UV-9LVWURQJSKkQKӫy RhB cӫa mүu vұt liӋu NiFe 2 O 4 /BiVO 4 (B)
MөFWLrXYjQӝLGXQJQJKLrQFӭu
0өFWLrXQJKLrQFӭXFӫDNKyDOXұQQj\OjWәng hӧp vұt liӋXFRPSRVLWH[~FWiFTXDQJKyD BiVO4 YjYұt liӋu composite NiFe2O4/BiVO4 ӭng dөng trong xӱ OêFKҩt PjXKӳXFѫGѭӟLiQKViQJQKuQWKҩy
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1.2.2 NӝLGXQJQJKLrQFӭu ĈӇÿiSӭQJÿѭӧFPөFWLrXQJKLrQFӭXQKѭWUrQQӝLGXQJQJKLrQFӭXFӫDÿӅ WjLEDRJӗm:
1JKLrQFӭXTX\WUuQKWәng hӧp vұt liӋXFRPSRVLWH[~FWiFTXDQJKyDBiVO4
YjNiFe2O4/BiVO4 ĈiQKJLiÿһFWUѭQJFҩXWU~FFӫa vұt liӋu tәng hӧSÿѭӧc bҵQJFiFSKѭѫQJSKiS
;5'[iFÿӏQKKuQKWKiLWLQKWKӇ cӫa vұt liӋu tәng hӧSÿѭӧc bҵQJSKѭѫQJSKiS6(0 [iFÿӏnh vұt liӋu hҩp thө iQKViQJQKuQWKҩy bҵQJSKѭѫQJSKiS89-vis DRS vjquang phә WiQ[ҥ Raman
KhҧR ViW ÿiQK JLi KRҥW WtQK TXDQJ [~F WiF Fӫa vұt liӋX [~F WiF TXDQJ KyD BiVO4 trong phҧn ӭQJSKkQKӫ\PjX&9Yjvұt liӋu composite NiFe2O4/BiVO4 trong phҧn ӭQJSKkQKӫ\PjX5K%GѭӟLiQKViQJQKuQWKҩy
1.3 ĈӕLWѭӧQJYjSKҥm vi QJKLrQFӭu ĈӕLWѭӧQJQJKLrQFӭu
&iFÿӕLWѭӧQJQJKLrQFӭu bao gӗm:
- ChҩWPjXKӳXFѫFU\VWDOYLROHWYj5KRGDPLQH%WURQJQѭӟc giҧ thҧi
Thӡi gian thӵc hiӋQÿӅ WjLFyJLӟi hҥQFQJ vӟi nhӳng hҥn chӃ NKiFKTXDQPhҥPYLQJKLrQFӭu tiӃQKjQKNKҧRViWTXiWUuQKTuang [~FWiF chҩWPjX hӳXFѫFӫa BiVO4 YjNiFe2O4/BiVO4 tҥi ÿLӅu kiӋQP{LWUѭӡQJYjFѫVӣ vұt chҩt cӫa SKzQJWKt nghiӋm khoa hӑc vұt liӋu WUѭӡQJĈҥi hӑc NguyӉn TҩW7KjQK
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éQJKƭDNKRDKӑFYjWKӵc tiӉn
Chӭng minh bҵng thӵc nghiӋm vұt liӋX [~F WiF TXDQJ KyD %L924 Yj NiFe2O4/BiVO4 FyWKӇ xӱ Oêÿѭӧc chҩWPjXKӳXFѫFKRKLӋu suҩt cao
KӃt quҧ QJKLrQFӭu cӫDÿӅ WjLÿѭDUDPӝWSKѭѫQJSKip xӱ OêchҩWPjXKӳXFѫ
Fy WURQJFiFQJXӗQQѭӟFSKiWWKҧLUDP{LWUѭӡng, ÿһc biӋWOjQJXӗQQѭӟc thҧi tӯ QJjQK F{QJ QJKLӋp dӋt nhuӝm ÿLӅX Qj\ cho thҩy vұt liӋX [~F WiF TXDQJ KyD %L924 Yj NiFe2O4/BiVO4 hӭa hҽQOjPӝt vұt liӋu tiӅPQăQJFyêQJKƭDWKӵc tiӉn cho hoҥWÿӝng xӱ OêQѭӟc thҧi chӭDPjX
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Tәng quan vӅ vұt liӋX[~FWiFTXDQJKyD
4XDQJ[~FWiFWKѭӡQJÿѭӧc sӱ dөQJÿӇ P{Wҧ mӝWTX\WUuQKPjiQKViQJÿѭӧc sӱ dөQJÿӇ NtFKKRҥt mӝt loҥi chҩWÿѭӧc gӑLOjFKҩW[~FWiFTXDQJFKҩWQj\FyWiF dөQJWKD\ÿәi tӕFÿӝ phҧn ӭQJKyDKӑFPjNK{QJWKDPJLDYjRTXiWUuQKELӃQÿәLKyD hӑF7KHR,83$&TXDQJ[~FWiFOjSKҧn ӭQJ[~FWiFOLrQTXDQÿӃn sӵ hҩSWKXiQK ViQJFӫa chҩt nӅQ+D\QyLFiFKNKiFTXDQJ[~FWiFOjQKӳng phҧn ӭng xҧy ra khi FyiQKViQJYjFKҩW[~FWiF.KLFyVӵ NtFKWKtFKiQKViQJFyEѭӟFVyQJWKtFKKӧp, electron tӯ YQJKyDWUӏ sӁ bӏ NtFKWKtFKGLFKX\ӇQOrQYQJGүn, tҥo ra cһp electron ± lӛ trӕng quang sinh Phҧn ӭQJ[~FWiFTXDQJKyDOjPӝWF{QJQJKӋ ÿѭӧc ӭng dөng rӝQJUmLWURQJQKLӅXOƭQKYӵFQKѭSKkQKӫy hӧp chҩt hӳXFѫYjFKҩWPjXNKiQJNKXҭn YjWҥRUDQKLrQOLӋXWK{QJTXDYLӋFSKkQWiFKQѭӟFYjNKӱ carbon dioxide
Nhӳng chҩW[~FWiFTXDQJWUX\Ӆn thӕQJÿDVӕ OjFiFYұt liӋXEiQGүQFK~QJOj oxit cӫDFiFNLPORҥi chuyӇn tiӃSQKѭ7L22, ZnO, WO3, FeTiO37URQJÿy7L22 Oj chҩWFyNKҧ QăQJ[~FWiFTXDQJKyDPҥQKYjÿѭӧFTXDQWkPQJKLrQFӭu trong nhӳng QăPJҫQÿk\Yu7L22 FyFKLSKtFKӃ tҥo rҿNK{QJÿӝc hҥi, bӅn nhiӋWYjWKkQWKLӋn vӟi P{LWUѭӡQJFyNKҧ QăQJR[\KyDÿѭӧFFiFFKҩt hӳXFѫYӟi sҧn phҭm cuӕLFQJOj
CO2, H22YjFiFLRQY{FѫtWÿӝc hҥLFyNKҧ QăQJFKӕng mӕFYjNKҧ QăQJWӵ OjP sҥFK1JRjLUDFzQFyNKҧ QăQJNKӱ [~FWiFNKtJk\KLӋu ӭQJQKjNtQK&22 WKjQK QKLrQOLӋu [9]
7X\QKLrQORҥi vұt liӋu TiO2 lҥLFyQăQJOѭӧQJYQJFҩm lӟQH9YjWKӡi JLDQWiLWә hӧSFiFFһSHOHFWURQYjOӛ trӕng diӉn ra nhanh dүQÿӃn hiӋu quҧ TXDQJKyDNpP9uYұ\ÿk\OjPӝt trong nhӳQJWKiFKWKӭFÿӕi vӟLFiFQKjNKRDKӑc vӅ OƭQKYӵc QJKLrQcӭX[~FWiFTXDQJOjOjPVDRÿӇ WăQJPӭFÿӝ nhҥ\iQKViQJFӫa vұt liӋX[~FWiFTXDQJYӅ YQJiQKViQJQKuQWKҩ\ĈӇ giҧi quyӃWWKiFKWKӭFWUrQFyKDLFKLӃQOѭӧc FKtQKÿѭӧFÿѭDUDÿyOjELӃQWtQKYұt liӋXTXDQJ[~FWiF7L22 truyӅn thӕQJYjQJKLrQ cӭXSKiWWriӇn vұt liӋXTXDQJ[~FWiFPӟL7URQJÿyKѭӟQJSKiWWULӇn vұt liӋu quang
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[~FWiFPӟLÿDQJÿѭӧFFiFQKjQJKLrQFӭXÿһc biӋWTXDQWkP0ӝt trong sӕ ÿyOj BiVO4 cho thҩy tiӅPQăQJUҩt lӟQYuFK~QJFKRNKҧ QkQJSKkQKӫ\FDRGѭӟLiQKViQJ QKuQWKҩ\WURQJTXiWUuQKTXDQJ[~FWiFFyÿӝ bӅQKyDKӑFYjKRҥWWtQKTXDQJKyD WѭѫQJÿӕi cao [10]
2&ѫFKӃ phҧQӭQJ[~FWiFTXDQJKyDGӏ thӇ
4XiWUuQK[~FWiFTXDQJFyWKӇ ÿѭӧc tiӃQKjQKӣ SKDNKtKRһc pha lӓQJ4Xi WUuQKTXDQJ[~FWiFÿѭӧFFKLDWKjQKJLDLÿRҥQQKѭVDX
(1) 4XiWUuQKNKXӃFKWiQFKҩt tham gia phҧn ӭng tӯ pha lӓng hoһFNKtÿӃn bӅ mһW[~FWiF
(2) Chҩt tham gia phҧn ӭQJÿѭӧc hҩp phө OrQEӅ mһt chҩW[~FWiFWK{QJ qua hҩp phө vұWOêKRһc hҩp phө KyDKӑc
(3) Vұt liӋXTXDQJ[~FWiFKҩp thө SKRWRQiQKViQJYjSKkQWӱ chuyӇn tӯ trҥQJ WKiL Fѫ Eҧn sang trҥQJ WKiL NtFK WKtFK Yӟi sӵ chuyӇn mӭF QăQJ Oѭӧng cӫa electron
(4) Phҧn ӭQJTXDQJKyD[ҧ\UDÿѭӧFFKLDOjPJLDLÿRҥn nhӓ:
+ Phҧn ӭQJTXDQJKyDVѫFҩSFiFSKkQWӱ chҩWEiQGүn bӏ NtFKWKtFKWKDPJLD trӵc tiӃSYjRShҧn ӭng vӟLFiFFKҩt bӏ hҩp phө
+ Phҧn ӭQJTXDQJKyDWKӭ cҩSFzQJӑLOjJLDLÿRҥn phҧn ӭQJ³WӕL´KD\SKҧn ӭng nhiӋWGyOjJLDLÿRҥn phҧn ӭng cӫDFiFVҧn phҭm thuӝFJLDLÿRҥQVѫFҩp
(5) Nhҧ hҩp phө FiFVҧn phҭm khӓL[~FWiF
(6) KhuӃFKWiQFiFVҧn phҭm phҧn ӭnJYjRSKDNKtKRһc lӓng
Phҧn ӭQJ[~FWiFTXDQJKyDKLӋQQD\ÿѭӧFTXDQWkPQJKLrQFӭXNKiFYӟi phҧn ӭQJ[~FWiFWUX\Ӆn thӕng ӣ FiFKKRҥWKyD[~FWiFWURQJJLDLÿRҥQĈӕi vӟi phҧn ӭng [~FWiFWUX\ӅQWK{QJ[~FWiFÿѭӧc hoҥWKyDEӣLQăQJOѭӧng nhiӋWFzQWUong phҧn ӭng TXDQJ[~FWiFTXDQJKyDKLӋQQD\[~FWiFÿѭӧc hoҥWKyDEӣi sӵ hҩp thө TXDQJQăQJ iQKViQJ&ө thӇ JLDLÿRҥQWURQJTXiWUuQKTXDQJ[~FWiFGLӉQUDQKѭ+uQK.1 Khi chҩW[~FWiFTXDQJGѭӟLWiFGөng cӫDFiFSKRWRQiQKViQJYӟLQăQJOѭӧng bҵng hoһc lӟQKѫQQăQJOѭӧQJYQJFҩm (Eg), electron (e - ) tӯ YQJKyDWUӏ (VB, valence band)
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3*676%L;XkQ7KjQK sӁ bӏ NtFKWKtFKYjGLFKX\ӇQVDQJYQJGүQ&%FRQGXFWLRQEDQGÿӇ lҥLFiFOӛ trӕng (h + ) ӣ 9%EѭӟF,WURQJ+uQK.1) Sӵ KuQKWKjQKFiFFһp e - Yjh + OjFҫn thiӃt chRTXi WUuQKR[LKyDYjNKӱ [~FWiFTXDQJKyD&iFFһSHOHFWURQYjOӛ trӕQJTXDQJVLQKQj\ tiӃp tөc trҧLTXDFiFTXiWUuQKWLӃp theo: di chuyӇQÿӃn bӅ mһt cӫa vұt liӋXEiQGүn Eѭӟc II), bӏ bҳt giӳ lҥi tҥLFiFYӏ WUtNKX\Ӄt tұt trong khӕi hoһFWUrQYQJEӅ mһt cӫa vұt liӋXEiQGүQEѭӟF,,,YjTXiWUuQKWiLWә hӧSNqPWKHRJLҧLSKyQJQăQJOѭӧng tҥRWKjQKGѭӟi dҥng nhiӋt hoһc photon diӉQUDEѭӟF,,ả
+uQK.1 6ѫÿӗ QJX\rQOêNKҧ QăQJ[ӭFWiFTXDQJKyD 2.1.3 &iFORҥL[~FWiFTXDQJWKѭӡng sӱ dөng
9ұWOLӋu[~FWiFTXDQJKyDÿyQJYDLWUzTXDQWUӑng trong nhiӅXOƭQKYӵFQKѭ cҧi thiӋQP{LWUѭӡQJӭQJGөQJTXDQJÿLӋQӭQJGөQJVLQKKӑc, sҧQ[XҩWQăQJOѭӧQJ VҥFKFҧm biӃn, linh kiӋQÿLӋn tӱNtFKFӥQDQRSLQPһt trӡL6ӵSKiWWULӇn vӅOƭQKYӵF nghirQFӭXYjFKӃWҥRQKLӅXGҥQJYұWOLӋXQDQRFyFҩXWU~FKuQKGҥQJNKiFQKDXFKR FiFӭQJGөQJ NKiFQKDXÿzLKӓLVӵSKiWWULӇQWѭѫQJӭQJYӅQJKLrQFӭXTX\WUuQK ÿiQKJLiYjFKҩWQKұQELӃWWtQKQăQJTXDQJ[~FWiFFKRWӯQJGҥQJYұWOLӋu NhӳQJ FKҩW[~FWiFTXDQJWUX\Ӆn thӕng chӫ yӃXOjFiFR[LWNLPORҥLQKѭ7L22, ZnO, SnO2
Yj&H227URQJÿy7L22OjFKҩWFyNKҧQăQJ[~FWiFTXDQJKyDPҥQKYjÿѭӧFTXDQWkPQJKLrQFӭXVkXUӝng trong nhӳQJQăPJҫQÿk\YuFiFOtGRQKѭ[9]
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&yFKLSKtFKӃWҥRUҿNK{QJÿӝFKҥLEӅn nhiӋWYjWKkQWKLӋn vӟLP{LWUѭӡng
&yNKҧQăQJSKiWKX\WiFGөQJ[~FWiFTXDQJKyDQKDQKӣ ÿLӅu kiӋn mӅm
&yNKҧ QăQJR[\KyDÿѭӧFFiFKӧSFKҩWKӳXFѫYӟi sҧQSKҭPFXӕLFQJOj
&yNKҧ QăQJFKӕng mӕc, diӋWNKXҭQYjNKҧQăQJWӵOjPVҥFK
&yNKҧ QăQJSKkQKӫ\FiFNKtWKҧLÿӝc tӯ ÿӝQJFѫ{W{[HPi\QKѭ12x
&yNKҧ QăQJSKkQKӫ\TXDQJÿLӋQKyD[~FWiF+22WKjQK+2 Yj22WҥR QăQJOѭӧng mӟi
(7) Khҧ QăQJNKӱTXDQJ[~FWiFNKtJk\KLӋXӭQJQKjNtQK&22 WKjQKQKLrQ liӋu
TiO2FyGҥQJWLQKWKӇ ÿLӇQKuQKOjDQDWDVHEURRNLWHYjUXWLOHWURQJWURQJ F{QJQJKLӋp chӫ yӃu sӱGөQJӣGҥQJDQDWDVHYjEURRNLWH[11] TiO2 ӣGҥQJDQatase FyKLӋu quҧ[~FWiFTXDQJFDRQKҩWWURQJSKkQKӫ\FKҩW{QKLӉm hӳXFѫY{Fѫӣ cҧ GҥQJNKtYjGҥQJOӓQJWURQJNKLEURRNLWHYjUXWLOHtWOLQKÿӝQJKѫQ[12]
+uQK.2 CҩXWU~FWLQKWKӇ (a) anatse, (b) brookite, (c) rutile cӫa TiO2[13]
&iFÿһFWtQKTXDQJ[~FWiFFӫa TiO2SKөWKXӝFYjRQKLӅXWK{QJVӕ QKѭNtFKWKѭӟFKҥWGLӋQWtFKEӅ mһt, thӇ WtFKOӛ trӕQJKjPOѭӧQJK\GUR[\OYjÿӝ kӃt tinh [12]
Lu̵QYăQWK̩FVƭ CBHD: TS Nguy͍n Duy Trinh
4XiWUuQK[~FWiFTXDQJKyDFӫa TiO2 GѭӟLWiFGөQJFӫa mӝWSKRWRQiQKViQJFyQăQJ OѭӧQJH9WѭѫQJӭQJYӟLiQKViQJFyEѭӟFVyQJQKӓ KѫQQPFKtQKOjGҧi EѭӟFVyQJFӫD89$VӁ[ҧ\UDTXiWUuQKWKӫ\SKkQQѭӟc bӣLWLD89WKjQK+2 Yj22
Vӟi khҧQăQJTXDQJ[~FWiFWӕt, TiO2ÿmÿѭѫFQJKLrQFӭXUӝQJUmLWURQJFiF OƭQKYӵFOjPVҥFKQѭӟc thҧLYjNK{QJNKt{QKLӉPWURQJF{QJQJKLӋSYjRQKӳQJQăP 9jRQKӳQJQăPVDXÿy7L22FҩXWU~FQDQRÿѭӧFQJKLrQFӭXӭQJGөQJUӝQJUmL trong ciFOƭQKYӵFFKҩWPDQJWURQJSLQPһt trӡLFKҩWPjXQKҥ\TXDQJOjPÿLӋQFӵF TXDQJÿLӋQSKkQQѭӟFWҥRK\GURWҥRFiFKӧSFKҩWKӳXFѫ[ӱ OêQѭӟFYjGLӋWYLNKXҭQ HiӋQQD\QJj\FjQJFyQKLӅXFKҩWEiQGүQFyKRҥWWtQK[~FWiFTXDQJÿѭӧFQJKLrQ FӭXYjӭQJGөQJ&iF[~FWiFTXDQJQj\Fҧi thiӋn yӃXÿLӇPWK{QJTXDFiFSKѭѫQJ SKiSÿӇ kiӇPVRiWKuQKWKiLYjNtFKWKѭӟFKҥWQKѭSKDWҥSNLPORҥLKD\SKDWҥSSKL NLPWҥRYұWOLӋXFRPSRVLWHWUrQFѫVӣFiFYұWOLӋX[~FWiFTXDQJWUX\Ӆn thӕng hoһc phӫFiFNLPORҥLTXêÿӇWăQJKRҥWWtQK[~FWiFTXDQJFӫDFiFYұWOLӋu truyӅn thӕng 1JRjLUDFiFORҥL[~FWiFTXDQJKLӋQÿѭӧFQJKLrQFӭXYjVӱGөQJUӝQJUmLOj6U7L23,
WO3, ZnS, FeTiO3, Bi2O3, BiVO4.
Tәng quan vӅ vұt liӋu BiVO 4
BiVO4 ӣ ÿLӅu kiӋQWKѭӡQJOjFKҩWEӝt rҳQPjXYjQJNK{QJWDQWURQJQѭӟc QKѭQJWDQWURQJDFLGSKkQWiQWӕWNK{QJÿӝFKҥLEӅn nhiӋt, khҧQăQJKҩSSKөEӅ mһt ӣPӭFWUXQJEuQK-yӃXW\WKHRKuQKWKiLWLQKWKӇ9u BiVO4OjYұWOLӋXEiQGүQQrQӣ ÿLӅu kiӋXWKѭӡQJÿӝ dүQÿLӋQNpPQKѭQJNKLÿѭӧFNtFKWKtFKEӣLiQKViQJFyEѭӟc VyQJWKtFKKӧSWKuÿӝ dүQÿLӋn cӫDQyWăQJOrQ [14][15]
BiVO4 OjPӝt loҥL[~FWiFTXDQJKyDFyNhҧ QăQJSKkQKӫ\FiFFKҩW{QKLӉm, SKkQWiFKQѭӟFYjNKӱ CO2 GѭӟLWiFGөng cӫDiQKViQJQKuQWKҩ\WKXK~WQKuXVӵ TXDQWkPBiVO4 ÿѭӧc biӃWÿӃQFyEDGҥng cҩXWU~FWLQKWKӇ: monoclinic scheelite (s- m BiVO4), tetragonal zircon (z-t BiVO4), tetragonal scheelite (s-t BiVO4) [16] Cҩu WU~FWLQKWKӇ cӫa BiVO4 ÿѭӧc thӇ hiӋn ӣ +uQh 2.37URQJÿyFKӍ FyV-m BiVO4 thӇ hiӋn hoҥWWtQK[~FWiFTXDQJKyDFDRQKҩWGѭӟLYQJiQKViQJQKuQWKҩy, s-m BiVO4
Lu̵QYăQWK̩FVƭ CBHD: TS Nguy͍n Duy Trinh
FyQăQJOѭӧQJYQJFҩm hҽp (2.4 eV) bӣLYuNKLKҩp thө iQKViQJHOHFWURQEӏ NtFK WKtFKVӁ di chuyӇn tӯ YQJKya trӏ 9%RUELWDOODLKyD cӫD%LVYj2SÿӃQYQJ dүn (CB) cӫD9GQKѭ+uQK.4 minh hӑa cҩXWU~FYQJFӫa tetragonal zircon BiVO4
YjPRQRFOLQLFVFKHHOLWHBiVO4 ÿѭӧFÿӅ xuҩt bӣL.XGRYjFiFFӝng sӵ [17]
+uQK.4 CҩXWU~FYQJFӫa tetragonal zircon BiVO4 YjPRQRFOLQLFVFKHHOLWH
BiVO4 ÿѭӧFÿӅ xuҩt bӣL.XGRYjFiFFӝng sӵ [17]
1JKLrQFӭXFӫD.XGRFQJFӝQJVӵÿmFKӭQJPLQKUҵQJKuQKGҥQJFҩXWU~F tinh thӇSKөWKXӝFYjRSKѭѫQJSKiSWәng hӧp, nhiӋWÿӝ YjWӍ lӋ Bi:V Monoclinic BiVO4 ÿѭӧc tәng hӧp bҵQJ SKѭѫQJ SKiS QJKLӅn bӝt ӣ nhiӋW ÿӝ cao trong khi tetragonal BiVO4 tәng hӧp bҵQJSKѭѫQJSKiSNӃt tӫa tӯ dung dӏch Bi(NO3)3 YjGXQJ
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3*676%L;XkQ7KjQK dӏch NH4VO3 ӣ nhiӋW ÿӝ SKzQJ 7URQJ EiR FiR Qj\ XGR FQJ FӝQJ Vӵ FNJQJ ÿm FKӭQJPLQKÿѭӧc rҵQJFҩXWU~F]-t BiVO4VӁFKX\ӇQWKjQKFҩXWU~FV-m BiVO4 khi nung trong khoҧng nhiӋWÿӝ 670-770 Ƞ WX\QKLrQÿӃn nay vүQFKѭDFyEiRFiRNKRD hӑFQjRFKӭQJPLQKVӵFKX\ӇQSKDQJѭӧFOҥLWӯFҩXWU~FV-m BiVO4WKjQKFҩXWU~F z-t BiVO4 WKjQKF{QJ0һWNKiFFҩXWU~FV-t BiVO4 FyWKӇ chuyӇQWKjQKFҩXWU~FV- m BiVO4 NKLÿѭӧc nung ӣ 528 Ƞ K TӍ lӋ giӳD%L9OjKuQKWKjQKSKDWLQKWKӇ PRQRFOLQLFYjFyKLӋu quҧ[~FWiFTXDQJFDRGѭӟLiQKViQJQKuQWKҩ\[18]
+uQK.5 CҩXWU~FBiVO4 kiӇu scheelite (a), s-t BiVO4 (b), m-s BiVO4 (c) [19]
1JKLrQFӭu cӫD.DLQLQJYjFӝng sӵ cho thҩy rҵQJÿӕi vӟi monoclinic BiVO4
QJX\rQWӱ 9ÿѭӧc bao quanh bӣi bӕQQJX\rQWӱ O tҥRWKjQKWHWUDKHGURQVO4QJX\rQ tӱ %Lÿѭӧc phӕi hӧSYyLWiPQJX\rQWӱ O tҥRWKjQKGRGHFDKHGUR%L28Ĉӕi vӟLFiF SKDWHWUDJRQDOFiFQJX\rQWӱ FNJQJÿѭӧc phӕi hӧSQKѭP BiVO4QKѭQJVӵ ÿӕi xӭng FiF ÿD GLӋQ Oj NKiF QKDX Ĉӝ GjL OLrQ NӃt Bi-2 WUXQJ EuQK JLҧP WKHR WUuQK Wӵ m-s BiVO4 > s-t BiVO4 > z-t BiVO4WURQJNKLÿӝ GjLFӫDOLrQNӃt V-O cӫa tҩt cҧ FiFSKD OjWѭѫQJWӵ QKDX%rQFҥQKÿyQJKLrQFӭu cӫD.ZHRQYjFӝng sӵ cho thҩy trong cҩu WU~FBiVO4 kiӇXVFKHHOLWHQKѭ+uQK.5 (a), VO4 WHWUDKHGURQPjX[iPOjJyFNӃt nӕi bӣi BiO8 GRGHFDKHGURPjXWtP7URQJV-t BiVO4+uQK.5 (b), cation Bi 3+ Yj
V 5+ ÿѭӧFÿһt tҥLFiFYӏ WUtÿӕi xӭng cӫa BiO8 Yj924 WѭѫQJӭng, cho bӕQOLrQNӃt V-2WѭѫQJÿѭѫQJYjKDLEӝ bӕQOLrQNӃt Bi-2WѭѫQJÿѭѫQJ7URQJV-m BiVO4+uQK
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1.5 (c) cation Bi 3+ Yj9 5+ ÿѭӧc dӡi khӓLFiFYӏ WUtÿӕi xӭng dӑc theo trөFFÿѭӧc chӍ bӣLPNJLWrQJLҧPÿLӇPÿӕi xӭng cӫDFiFYӏ WUtFDWion [19]
2.2.2 1JX\rQOê[~FWiFTXDQJKyD cӫa vұt liӋu BiVO 4
Khi vұt liӋu BiVO4 GѭӟLWiFGөng cӫDFiFSKRWRQiQKViQJYӟLQăQJOѭӧng bҵng hoһc lӟQKѫQQăQJOѭӧQJYQJFҩm (Eg), electrons (e ỉ ) tӯ VB sӁ bӏ NtFKWKtFK
YjGLFKX\ӇQVDQJ&%ÿӇ lҥLFiFOӛ trӕng (h + ) ӣ 9%EѭӟFYjWURQJKuQK)
Sӵ KuQKWKjQKFiFFһp e ỉ YjK + OjFҫn thiӃWFKRTXiWUuQKR[LKyDYjNKӱ [~F
WiFTXDQJKyD&iFFһSHOHFWURQYjOӛ trӕQJTXDQJVLQKQj\WLӃp tөc trҧLTXDFiFTXi
WUuQKWLӃSWKHREѭӟc 3) di chuyӇQÿӃn bӅ mһt cӫa vұt liӋXEѭӟc 4) bӏ giӳ lҥi tҥLFiF vӏ WUtNKX\Ӄt trong khӕi hoһFWUrQYQJEӅ mһt cӫa vұt liӋXYjEѭӟFTXiWUuQKWiL tә hӧSYjJLҧLSKyQJQăQJOѭӧng tҥRWKjQKQKLӋt hoһc photon diӉn ra
ViӋc di chuyӇQQj\VӁÿӇOҥLFiFOӛ trӕng (h + ) ӣ 9%&iFFһSHOHFWURQYjOӛ trӕQJTXDQJVLQKQj\WLӃSWөFWUҧLTXDFiFTXiWUuQKWLӃp theo: di chuyӇQÿӃn bӅ mһt cӫDYұWOLӋu, bӏ bҳt giӳOҥLWҥLFiFYӏ WUtNKX\ӃWWұWWURQJNKӕi hoһFWUrQYQJEӅ mһt cӫDYұWOLӋX&iFOӛ trӕng (h + VDXNKLKuQKWKjnh phҧQӭQJYӟLQѭӟFÿӇ VLQKUDFiF gӕc OH WURQJNKLFiFHOHFWURQH ỉ ) phҧQӭQJYӟi O2 ÿӇWҥRUDJӕc ଶ xି WӵGR&iFJӕF
WӵGRQj\VӁWLӃSWөFSKҧQӭQJYӟLFKҩW{QKLӉPYjSKkQKӫ\FK~QJ
7X\QKLrQGRÿһFWtQKFKX\ӇQÿLӋQWtFKNpPYjEӅ mһt hҩp phө NpPQrQGүn ÿӃQTXiWUuQKWiLWә hӧp cӫDFiFHOHFWURQYjOӛ trӕQJEѭӟc 5 chiӃPѭXWKӃ) dүQÿӃn kӃt quҧ OjKRҥWWtQKTXDQJKyDFӫa BiVO4 bӏ hҥn chӃ [22] Nhҵm khҳc phөFÿѭӧFÿLӅu
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3*676%L;XkQ7KjQK ÿyYjQKҵPOjPWăQJKRҥWWtQKTXDQJ[~FWiFFӫa vұt liӋXFiFFKҩWR[\KyDFKҩt nhұn ÿLӋn tӱ) sӁ ÿѭӧc bә VXQJYjRGXQJGӏch phҧn ӭQJ.KLÿyFiFFKҩWR[\KyDÿѭӧc bә sung sӁ nhұQÿѭӧFÿLӋn tӱ WURQJYQJGүn cӫa BiVO4 (e ỉ ) YjFXӕLFQJWҥRWKjQK2+x Gӕc OHx OjPӝWWiFQKkQR[LKyDUҩt mҥQKNK{QJFKӑn lӑFYjFyNKҧ QăQJR[LKyD hҫu hӃWFiFFKҩt hӳXFѫ4XiWUuQKSKkQKӫy mӝt sӕ hӧp chҩt hӳXFѫGLӉQUDQKѭVDX [21]:
+uQh 2.6 &ѫFKӃ phҧn ӭng cӫa vұt liӋu BiVO4
7KHRFiFQJKLrQFӭXWUѭӟFÿk\FKӍ ra rҵQJSKѭѫQJSKiSWәng hӧp vұt liӋXFy mӭc ҧQKKѭӣQJÿiQJNӇ ÿӃQKuQKWKiLNtFKWKѭӟc hҥt, bӅ mһWULrQJYjFҩXWU~FWLQK thӇ cӫa vұt liӋX[~FWiFTXDQJKyDGӏ thӇQyTX\ӃWÿӏQKÿӃQWtQKKҩp phө YjKRҥWWtQK TXDQJKyDFӫa vұt liӋX&iF3KѭѫQJSKiSFKtQKÿӇ tәng hӧp vұt liӋXQKѭSKѭѫQJ SKiSWKӫy nhiӋt, kӃt tӫa, sol-gel, dung nhiӋWR[\KyDWUӵc tiӃp, kӃt tӫa bҵQJED\KѫL vұWOêKRһFKyDKӑFSKѭѫQJSKiS YLVyQJYjVLrXkP
3KѭѫQJSKiSKӛ trӧ YLVyQJWKѭӡQJÿѭӧc gӑLOjSKѭѫQJSKiSOjPWăQJWӕFÿӝ phҧn ӭQJYjWKѭӡng xҧy ra ӣ nhiӋWÿӝ thҩSKѫQVRYӟi sӵ OjPQyQJFӫDFiFSKѭѫQJSKiSWK{QJWKѭӡQJNKiF[23]7URQJSKѭѫQJSKiSKӛ trӧ YLVyQJFiFYұt liӋX[~FWiFTXDQJFyWKӇ ÿѭӧFQXQJQyQJÿӗQJÿӅu dүQÿӃn cҩu tҥRÿӗng nhҩWYjGRÿyWҥo ra
Lu̵QYăQWK̩FVƭ CBHD: TS Nguy͍n Duy Trinh
NtFKWKѭӟc nhӓ KѫQFӫa cҩXWU~F[~FWiFTXDQJFyÿӝ tinh khiӃWFDRYjQăQJVXҩt sҧn xuҩWFDRKѫQ[24]1ăP0LQJYjFӝng sӵ [23] ÿmEiRFiRYLӋc chӃ tҥRWKjQK F{QJBiVO4 WK{QJTXDSKѭѫQJSKiSQj\WURQJÿySKDWLQKWKӇ FDRÿѭӧc chuyӇQÿәi NK{QJWKӇ ÿҧRQJѭӧc tӯ SKDWHWUDJRQDOVDQJSKDPRQRFOLQLF1JRjLUDSKѭѫQJSKiS sol-JHOFNJQJOjPӝt trong nhӳQJSKѭѫQJSKiSSKә biӃQÿӇ ÿLӅu chӃ [~FWiFTXDQJ BiVO4ѬXÿLӇm cӫa viӋc sӱ dөQJSKѭѫQJSKiSQj\OjQKӡ ÿӝ tin cұy sҧn xuҩWWѭѫQJ ÿӕi thҩSÿӝ ÿѫQJLҧn cӫDTX\WUuQK YjGӉ kiӇPVRiWKuQKWKiL[25]+ѫQQӳDÿӗng kӃt tӫDYjWәng hӧSÿӕWFKi\GXQJGӏFKOjPӝt trong nhӳng kӻ thuұt chӃ tҥRÿmÿѭӧFEiR FiRWUѭӟFÿk\[26]
MһWNKiFSKѭѫQJSKiSWәng hӧp thӫy nhiӋWÿmÿѭӧc sӱ dөng rӝQJUmLÿӇ tәng hӧp chҩW[~FWiFTXDQJBiVO4 nhӡ TX\WUuQKÿѫQJLҧn cӫDQyFyWKӇ tҥo ra cҩXWU~F tinh thӇ KRjQKҧo ӣ nhiӋWÿӝ WѭѫQJÿӕi thҩS4XiWUuQKWKӫy nhiӋt sӱ dөQJQѭӟc hoһc P{LWUѭӡng phҧn ӭQJ NK{QJ FyQѭӟF YjTX\ WUuQKWK~Fÿҭy sӵ WKkQWKLӋn vӟL P{L WUѭӡQJNKLFiFSKҧn ӭQJÿѭӧc thӵc hiӋn trong mӝt hӋ thӕQJNtQ1yLFKXQJFyEDVӵ WKD\ÿәLNKLÿLӅu chӃ BiVO4 WK{QJTXDSKѭѫQJSKiSQj\EҵQJFiFKWKrPLSKө gia hӳXFѫYjY{FѫKRһc (ii) chҩt hoҥWÿӝng bӅ mһWYjLLLKRһFNK{QJFҫQWKrPEҩt kǤ chҩt phө JLDQjRѬXÿLӇn cӫDSKѭѫQJSKiSWKӫy nhiӋWFyWKӇ tәng hӧp vұt liӋXGѭӟi ÿLӅu kiӋQNKiFQKDXNӻ thuұWÿѫQJLҧn, thiӃt bӏ rҿ tiӅn, thӡi gian tҥo mүXNKiQKDQK dӉ GjQJNLӇPVRiWÿѭӧFWKjQKShҫQFiFFKҩt tham gia phҧn ӭng, sҧn phҭPWKXÿѭӧc Fyÿӝ tinh khiӃWFDRNtFKWKѭӟc hҥt nhӓ ÿӗQJÿӅu, dӉ kiӇPVRiWQKLӋWÿӝ YjWKӡi gian [22]
Tәng hӧp vұt liӋX[~FWiFEҵQJSKѭѫQJSKiSWKӫy nhiӋWWKѭӡQJÿѭӧFQJKLrQ cӭu tURQJDXWRFODYHÿѭӧc gӑLOjEuQKWKӫy nhiӋW%uQKWKӫy nhiӋt gӗPEuQKFKӭa mүu YjEuQKEҧo vӋ%uQKFKӭa mүXOjPEҵQJWHIORQFyYDLWUzFKӭa dung dӏch phҧn ӭng, giӳ EuQKӣ thӇ WtFKNK{QJÿәLÿӇ phҧn ӭng xҧy ra ӣ nhiӋWÿӝ YjiSVXҩWFDR%uQKEҧo vӋ OjPEҵng WKpSNK{QJJKӍ giӳ YDLWUzOjPYӓ QJRjLWҥRiSOӵc giӳ chһWOjPNtQEӝ phұn chӭa mүXJL~SәQÿӏnh bӝ phұn chӭa mүu [27]
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NhiӅXQJKLrQFӭXWUѭӟFÿk\FKRWKҩy rҵng viӋc tәng hӧp vұt liӋu BiVO4 bҵng SKѭѫQJSKiSWKӫy nhiӋWOjPӝWSKѭѫQJSKiS hiӋu quҧ, dӉ thӵc hiӋQYjPDQJOҥi kӃt quҧ tәng hӧSFDR6KLYjFiFFӝng sӵ ÿmFKӍ ra rҵng kiӇPVRiWFKtQK[iFWURQJTXi WUuQKWKӫy nhiӋWOj\Ӄu tӕ then chӕWFKRSKpSWәng hӧSFiFYұt liӋu cҩXWU~FQDQRNKiF QKDX3KѭѫQJSKiSQj\FyWKӇ tҥRÿLӅu kiӋn thuұn lӧLYjÿҭy nhanh phҧn ӭng giӳa FiFFKҩt phҧn ӭQJWK~Fÿҭy thӫ\SKkQ+ѫQQӳDFiFWKXӝFWtQKKuQKWKiLNtFKWKѭӟc YjFҩXWU~FYұt liӋXFyWKӇ ÿѭӧFÿLӅu chӍnh dӉ GjQJEҵQJFiFKWKD\ÿәLFiFWK{QJVӕ phҧn ӭQJNKiFQKDXQKѭWKӡi gian phҧn ӭng, nhiӋWÿӝ, P{LWUѭӡng phҧn ӭQJiSVXҩt, S+YjQӗQJÿӝ cӫDFiFFKҩt phҧn ӭQJYjWKӇ WtFKWURQJDXWRFODYH3KѭѫQJSKiSQj\ FyWKӇ SKKӧp cho viӋc chuҭn bӏ vұt liӋu vӟi nhiӅXKuQKGҥng so vӟLFiFSKѭѫQJSKiS NKiF [28]
2.4 &iFSKѭѫQJSKiSQkQJFDRKRҥWWtQKFӫDBiVO 4
VӟLѭXÿLӇPQKѭFyQăQJOѭӧQJYQJFҩPKҽp, thӇ hiӋQKRҥWWtQKWURQJYQJ iQKViQJQKuQWKҩ\SKkQWiQWӕWYj NK{QJ ÿӝFKҥLBiVO4OjORҥLYұWOLӋX[~FWiF quDQJFyWLӅPQăQJOӟQYjÿҫ\KӭDKҽQ7X\QKLrQKRҥWWtQKTXDQJKyDFӫa BiVO4 chӍ ӣPӭFWUXQJEuQKYuNKҧQăQJKҩSSKөEӅ mһWYjFiFHOHFWURQVLQKUDWURQJTXi WUuQKTXDQJKyDGӉ WiLNӃt hӧp vӟLFiFOӛ trӕQJOjPJLҧPKRҥWWtQK[~FWiF [29][30] ĈӇ cҧi thiӋQYҩQÿӅ Qj\FiFQKjNKRDKӑFÿmÿѭDUDPӝt sӕ biӋQSKiSQKѭNLӇPVRiW FҩXWU~FWLQKWKӇQJKLrQFӭXYjWәng hӧSYұWOLӋXFҩXWU~FV-m BiVO4 hoһFFҩXWU~F dӏ pha monoclinic- tetragonal), kiӇP VRiW NtFK WKѭӟF Yj KuQK WKiL WLQK WKӇ BiVO4QJKLrQFӭXYjWәng hӧSYұWOLӋu BiVO4 vӟLNtFKWKѭӟFPLFURQDQRFyFҩXWU~FGҥQJWҩPGҥQJVӧLGҥQJӕQJGҥQJFҫXGҥQJNKӕLGҥQJKuQKTXHGҥQJKuQKWKRLKuQK
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3*676%L;XkQ7KjQK sao), biӃQWtQKBiVO4 bҵQJFiFKSKDWҥSSKLNLP&6%)KRһFNLPORҥL$X$J
Fe, Co, Ni, Cu, Ce), tәng hӧSYұWOLӋXFRPSRVLWHWUrQFѫVӣ nӅn BiVO4 [31]
2.43KѭѫQJSKiSNLӇPVRiWKuQKWKiLWLQKWKӇ ĈӇ QkQJFDRNKҧ QăQJTXDQJKyDFӫDORҥLYұWOLӋXEiQGүQWKuYLӋc chӃWҥRYұW liӋXWURQJÿyKuQKWKiLWLQKWKӇ ÿѭӧc kiӇPVRiWÿDQJWKXK~WQJKLrQFӭXÿiQJNӇ cӫa FiFQKjNKRDKӑF+XYjFӝQJVӵFӝQJVӵEiRFiRYӅ viӋc tәng hӧp s-m BiVO4GҥQJ WҩPYjÿiQKJLiҧQKKѭӣng cӫa nhiӋWÿӝ tәng hӧSOrQ khҧQăQJTXDQJ[~FWiFSKkQ hӫ\FKҩWPjX5K%GѭӟLWiFQKkQiQKViQJPһt trӡi [32]6XQYjFӝQJVӵÿLӅu chӃ WKjQKF{QJBiVO4GҥQJKuQKHOLSEҵQJSKѭѫQJSKiSÿѫQJLҧQYjNKҧRViWFiF ÿLӅu kiӋn vӅ JLiWUӏS+ORҥLWiFQKkQNӃt tӫa, nhiӋWÿӝ YjWKӡi gian dung nhiӋWSKkQ SKkQKӫy 96.5K%WURQJYzQJSK~W[31]%rQFҥQKÿyYLӋFÿLӇu khiӇn qXiWUuQK SKiWWULӇn tinh thӇ WKHRKѭӟQJѭXWLrQKuQKWKjQKPһt tinh thӇ FNJQJOjSKѭѫQJ SKiSKLӋu quҧ ÿӇQkQJFDRKRҥWWtQKTXDQJ[~FWiFFӫa s-m BiVO49tGөV-m BiVO4 GҥQJQDQRWҩPYӟLPұWÿӝ mһt tinh thӇ (010) cao thӇ hiӋQKRҥWttQKTXDQJ KyDFDR KѫQKҷn so vӟLYұWOLӋXGҥQJNKӕLWK{QJWKѭӡng trong phҧQӭQJSKkQKӫ\5K%Gѭӟi iQKViQJPһt trӡi Tinh thӇ vӟLPұWÿӝ FDRFyWKӇ WăQJKLӋu quҧ SKkQWiFKFӫa FiFFһp electron-lӛ trӕQJTXDQJVLQKYjWăQJFѭӡQJFiFEӅ mһWKRҥWÿӝQJFyOӧi cho viӋc cҧi thiӋQKRҥWWtQKTXDQJKyD [33][34][35]
2.43KѭѫQJSKiSNLӇPVRiWFҩXWU~FWLQKWKӇ
KӃt quҧ SKkQWtFKFҩXWU~FYұt liӋu BiVO 4
CҩX WU~F WLQK WKӇ cӫa BiVO4 ÿѭӧF [iF QKұQ WK{QJ TXD SKә nhiӉu xҥ tia X +uQKOjJLҧQÿӗ XRD cӫDFiFPүu BiVO4 ÿѭӧc tәng hӧp bҵng SKѭѫQJSKiSWKӫy nhiӋW.ӃWTXҧFKRWKҩ\FiFÿӍQKQKLӉX[ҥSKKӧSYӟLWKҿFKXҭn JCPDS no 14-0688 cӫa BiVO4 WѭѫQJӭng vӟLFiFYӏ WUtJyFș = 18,5; 29; 30,6; 35
Yj o YjSKKӧp vӟLQJKLrQFӭXWUѭӟFÿy [30]+ҵQJVӕPҥQJFӫDFiFPүXÿѭӧF WtQKEҵQJSKҫQPӅP8QLW&HOOSKҫQPӅPFKRSKpSWtQKWK{QJVӕPҥQJWLQKWKӇWӯGӳ OLӋXÿRJLҧQÿӗ;5'KӃt quҧ ÿѭӧFWUuQKEj\ӣ Bҧng 4.3 cho thҩ\NK{QJFyVӵ thay ÿәLÿiQJNӇ vӅ FiFKҵng sӕ mҥng tinh thӇ cӫa tҩt cҧ FiFPүu
+uQK.1 GiҧQÿӗ XRD chuҭn cӫa vұt liӋu BiVO4
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Bҧng 4.3 7K{QJVӕ mҥng tinh thӇ cӫDFiFPүu vұt liӋu
Mүu vұt liӋu 7K{QJVӕ mҥng ThӇ WtFK { mҥng tinh thӇ c
.tFK WKѭӟc tinh thӇ (nm) a b c
TrҥQJWKiLOLrQNӃt trong tinh thӇ BiVO4 ÿѭӧFQJKLrQFӭXWK{QJTXDSKә WiQ xҥ Raman Phә WiQ[ҥ Raman cӫDFiFPүu BiVO4 ÿѭӧc tәng hӧp ӣ FiFQKLӋWÿӝ NKiF QKDXÿѭӧFWUuQKEj\WURQJKuQK 4.2 Phә Raman cӫDFiFPүu BiVO4 cho thҩy dao ÿӝng mҥnh nhҩWOjGDRÿӝQJNpRGmQÿӕi xӭng V±O ӣ 825,04 cm -1 WURQJNKLÿyGDR ÿӝQJNpRGmQEҩWÿӕi xӭng cӫa V±O ӣ 651,57 cm -1 Yj cm -1 &iFÿӍQKGDRÿӝng ӣ 328,22 cm -1 Yj cm -1 ÿѭӧFJiQFKRGDRÿӝng biӃn dҥng bҩWÿӕi xӭQJYjÿӕi xӭng cӫDQKyP924 3-&iF GDRÿӝng ӣ 124,45 cm -1 Yj cm -1 OjFiFGDRÿӝng tә hӧSGDRÿӝQJTXD\GDRÿӝng tӏnh tiӃn) cӫa BiVO4 KӃt quҧ Qj\SKKӧp vӟLFiF kӃt quҧ QJKLrQFӭXWUѭӟFÿy [61]
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+uQK.2 Phә Raman cӫDFiFPүu vұt liӋu BiVO4
+uQK.3 cho thҩy kӃt quҧ chөp SEM cӫDFiFPүu vұt liӋXÿѭӧc tәng hӧp ӣ FiFQKLӋWÿӝ NKiFQKDX KӃt quҧ SEM cho thҩ\KuQKWKiLFӫa BiVO4 FyKuQKGҥng tӭ diӋn vӟi bӅ mһt nhҹQFQJYӟLFiFKҥt nhӓ&iFSKLӃn mӓQJÿyEDRJӗPFiFKҥt giӕng QKѭEұFWKDQJYjFiFEұFWKDQJÿyÿѭӧc xӃp dӑc theRFiFFҥnh cӫa phiӃn mӓQJ&iF TXDQViWWUrQFKRWKҩy rҵng nhӳng phiӃn mӓng giӕQJQKѭEұFWKDQJÿyFyWKӇ ÿѭӧc biӃQÿәi tӯ FiFKҥWQDQRYjWҩPQDQR&iFKҥWQDQRYjWҩPQDQRQj\FyWKӇ SKiWWULӇn YjWtFKWө ÿӇ tҥRWKjQKFiFSKLӃn mӓng giӕQJQKѭKuQKEұc thDQJFQJYӟi sӵ chuyӇn pha tӯ ÿDWLQKWKӇ WKjQK%L924 (sm)[62]
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+uQK.3 Ҧnh SEM cӫDFiFPүu (A) BVO_100, (B) BVO_120, (C) BVO_140, (D)
KӃt quҧ SKkQWtFKFҩXWU~FYұt liӋXFRPSRVLWHWUrQQӅn BiVO 4
CҩXWU~FWLQKWKӇ cӫa tҩt cҧ FiFPүu sӁ ÿѭӧF[iFÿӏQKWK{QJTXDSKѭѫQJSKiS nhiӉu xҥ tia X Tӯ dӳ liӋXÿRJLҧQÿӗ XRD cӫDFiFPүXÿѭӧc sӱ dөng phҫn mӅn origine YjOjPNKӟSFiFÿӍnh nhiӉu xҥ bҵQJKjP*DXVVÿӇ [iFÿӏnh vӏ WUtJyFș cӫDFiFÿӍnh nhiӉu xҥ trong tҩt cҧ FiFPүX+uQK.4 ErQGѭӟi cho thҩy giҧQÿӗ XRD FiFFӫa vұt liӋu tәng hӧp BiVO4YjNiFe2O4 YjNiFe2O4/BiVO4
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+uQK.4 GiҧQÿӗ XRD cӫa BiVO4 (A), 5% NiFe2O4/BiVO4 (B), 10% NiFe2O-
4/BiVO4 (C), 15% NiFe2O4/BiVO4 (D), 20% NiFe2O4/BiVO4 (E), 25% NiFe2O-
&iFPүu XRD cӫa vұt liӋu tәng hӧp BiVO4 YjNiFe2O4 YjNiFe2O4/BiVO4 ÿѭӧFWUuQKEj\WURQJ+uQK.4 &iFÿӍQKFKtQKӣ
YjTXDQViWWKҩy ÿѭӧc trong vұt liӋu tәng hӧp BiVO4 Yj NiFe2O4/BiVO4, cho thҩ\SKDFKtQKFӫa BiVO4 OjPRQRFOLQLFVFKHHOLWH [63][64][65] cho thҩy tҩt cҧ FiFPүXÿӅXFyFҩXWU~FWLQKWKӇ ӣ dҥng m-VÿѫQWLQKWKӇ Sӵ hiӋn diӋn cӫDFiFKҥt nano NiFe2O4 trong vұt liӋu tәng hӧp NiFe2O4/BiVO4 ÿmÿѭӧF[iFQKұn bӣi sӵ hiӋn diӋn cӫDFiFÿӍnh cӵFÿҥi ӣ Yj[66][67]%rQ cҥQKÿyFѭӡQJÿӝ cӫDÿӍnh ӣ 35,6WăQJOrQFQJYӟLWKjQKSKҫn% khӕLOѭӧng cӫa NiFe2O4 trong vұt liӋu tәng hӧp [48]&iFWK{QJVӕ mҥng tinh thӇ cӫa vұt liӋu tәng hӧp BiVO4 YjNiFe2O4/BiVO4 cho thҩy trong Bҧng 4.4 [iFQKұn rҵng sӵ lҳQJÿӑng cӫDFiFKҥt nano NiFe2O4 WUrQEӅ mһt BiVO4 NK{QJҧQKKѭӣQJÿiQJNӇ ÿӃn pha tinh thӇ YjFҩXWU~FFӫa BiVO4
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Bҧng 4.4 CiFWK{QJVӕ mҥng tinh thӇ cӫa vұt liӋu BiVO4 Yj1L)H2O4/ BiVO4
BiVO4 5.18521 5.09312 11.69186 90.00998 309.7689 5% NiFe2O4/BiVO4 5.19920 5.09872 11.72061 90.14443 310.7039 10% NiFe2O4/BiVO4 5.19548 5.09788 11.70849 89.99217 310.1106 15% NiFe2O4/BiVO4 5.20148 5.09951 11.70617 90.01030 310.5063 20% NiFe2O4/BiVO4 5.19850 5.09823 11.69956 90.07130 310.0747 25% NiFe2O4/BiVO4 5.20177 5.09721 11.71897 90.11685 310.7223
+uQKWKiLWLQKWKӇNtFKWKѭӟFYjSKkQEӕ hҥt cӫa vұt liӋXÿѭӧFTXDQViWWK{QJTXD NtQK KLӇQ YL ÿLӋn tӱ TXpW 6(0 Ӄt quҧ ҧnh SEM cӫa tҩt cҧ FiF Pүu hӧp BiVO4YjNiFe2O4 YjNiFe2O4/BiVO4 ÿѭӧFWUuQKEj\WURQJ+uQK4.5
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+uQK.5 ҧnh SEM cӫa BiVO4 (A), 20% NiFe2O4/ BiVO4 %Yj1L)H2O4 |(C), phә
KӃt quҧ SEM cho thҩyKuQKWKiLFӫa BiVO4 FyKuQKGҥng tӭ diӋn vӟi bӅ mһt nhҹQFQJYӟLFiFKҥt nhӓ +uQK4.5AWURQJNKLKuQKWKiLFӫa NiFe2O4 FyFiFKҥt nano vӟLÿѭӡQJNtnh trong phҥm vi 10 ± QP+uQK4.5C7URQJWUѭӡng hӧp mүu 20% NiFe2O4/BiVO4 +uQK4.5B) mӝW Oѭӧng lӟQ FiF KҥW QDQR ÿm ÿѭӧc lҳQJ ÿӑng WKjQKNKӕLOѭӧng lӟn, cho thҩy sӵ kӃt hӧp cӫDFiFKҥt nano NiFe2O4 WUrQEӅ mһt cӫa chҩW[~FWiFBiVO43KkQWtFK('6-MDSSLQJ[iFQKұn dҥQJKyDKӑc cӫa hӧp chҩt NiFe2O4/BiVO4 Yj Vӵ SKkQ Eӕ ÿӗQJ ÿӅu cӫD FiF QJX\rQ Wӕ 1L Yj )H WUrQ EӅ mһt BiVO4 +uQK4.5d-i) [48]
4.2.3 Phә phҧn xҥ khuӃFKWiQWӱ ngoҥi UV-Vis DRS
Khҧ QăQJKҩp thө iQKViQJӣ YQJEѭӟFVyQJQJҳQ89YjYQJEѭӟFVyQJGjLYQJiQKViQJNKҧ kiӃn) cӫa tҩt cҧ mүu vұt liӋXÿѭӧF[iFÿӏnh bҵQJKѭѫQJSKiSUV 9LV'56ÿѭӧc thӇ hiӋQWURQJ+uQK.6
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+uQK 4.6 Phә phҧn xҥ khuӃFKWiQ89B9,6$YjQăQJOѭӧQJYQJFҩm (B) cӫa
FiFYұt liӋu nano NiFe2O4, BiVO4 YjNiFe2O4/BiVO4
KӃt quҧ cho thҩy, tURQJ +uQK4.6A, cҥnh hҩp thө cӫa BiVO4 xuҩt hiӋn ӣ khoҧng 550 nm, trong khi NiFe2O4 FyKҩp thө rӝQJKѫQWURQJSKҥm vi iQKViQJQKuQ thҩy Cҥnh hҩp thө cӫa vұt liӋu nano NiFe2O4/BiVO4 xҧy ra trong phҥm vi 600-800 nm, cho thҩy sӵ hҩp thө trӣ QrQFDRKѫQVRYӟi BiVO4 tinh khiӃt sau khi ÿѭӧFÿtQK kӃt FiFKҥt nano NiFe2O4 MӭFQăQJOѭӧQJYQJFҩm (Eg, eV) cӫa tҩt cҧ FiFPүu ÿѭӧFÿѭӧFWtQKWRiQWK{QJTXDSKѭѫQJWUuQK7DXF [68][69]: ĮKY 2 = A (hv-Eg) 1/2 (1)
7URQJÿyĮOjKӋ sӕ hҩp thөKȞOjQăQJOѭӧng photon tӟL Yj $OjKҵng sӕ NK{QJ SKө thuӝF QăQJ OѭӧQJ *Li WUӏ YQJ Fҩm cӫa vұt liӋu NiFe2O4, BiVO4 Yj nanocomposite NiFe2O4/BiVO4 ÿѭӧc thӇ hiӋn trong Bҧng 3.3 *Li WUӏ Eg giҧm khi KjPOѭӧng NiFe2O4 WăQJ
9QJGүn (ECBYjYQJKyDWUӏ (EVB) cӫa NiFe2O4 YjBiVO4 FyWKӇ ÿѭӧFѭӟc WtQKEҵQJF{QJWKӭc [70][71]:
EVB = Eg ± ECB (3) ĈӝKҩSWKөDX
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TURQJÿy߯ Ojÿӝ kPÿLӋn tuyӋWÿӕi, ߯ lҫQOѭӧWOjH9YjH9ÿӕi vӟi BiVO4 YjNiFe2O4 [70][71] EȠ H9OjQăQJOѭӧng cӫDFiFHOHFWURQWӵ GRWUrQ WKDQJK\GUR*LiWUӏ ECB YjEVB cӫa BiVO4 lҫQOѭӧWOjYjH9*LiWUӏ ECB Yj
EVB cӫa NiFe2O4 lҫQOѭӧWOjYjH9 [48]
Bҧng 4.5 7tQK FKҩW KyD Oê Yj WKjQK SKҫQ KyD Kӑc cӫa mүu NiFe2O4 Yj NiFe2O4/BiVO4
KӃt quҧ ÿiQKJLiKRҥWWtQKTXDQJKyDFӫa vұt liӋu BiVO 4
4.3.1 HoҥWWtQKTXDQJ[~FWiFFӫa vұt liӋu BiVO 4
HoҥWWtQKTXDQJ[~FWiFFӫa vұt liӋu BiVO4 ÿѭӧFÿiQKJLiEҵng phҧn ӭQJSKkQ hӫy dung dӏFKPjX&U\WDO9LROHW ÿѭӧc tiӃQKjQKQKѭVDX&KRJFKҩW[~FWiFYjR cӕc chӭa 100 mL dung dӏch CV vӟi nӗQJÿӝ cӕ ÿӏQKSSPÿһWWUrQPi\NKXҩ\WӯYjNKXҩ\OLrQWөF7URQJSK~WNK{QJFKLӃXÿqQWKuFiFPүu vұt liӋXÿӅXÿmÿҥt ÿѭӧFFkQEҵng hҩp phө VDXÿyWLӃQKjQKFKLӃXÿqQ trong thӡi gian 4 giӡ ÿӇ ÿiQKJLi hoҥWWtQK[~FWiFTXDQJ Tҩt cҧ FiFPүu dung dӏch sDXNKLSKkQKӫ\ÿѭӧFO\WkPÿӇWiFKKӃt bӝW[~FWiF3Kҫn dung dӏch sau khi lӑF[~FWiFÿѭӧFPDQJÿLÿRPұWÿӝ
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TXDQJEҵQJPi\TXDQJSKә89-9LVYjQӗQJ ÿӝ &9ÿѭӧF[iFÿӏQKWKHRÿӏnh luұt Beer ± Lambert ӣ EѭӟFVyQJȜ QPYjÿѭӧFWtQKWKHRF{QJWKӭc[29]: ܥ ܥ ͼ ൌ ܣ ܣ ͼ
7URQJÿy&o Yj&OjQӗQJÿӝ cӫa dung dӏch CV ӣ thӡLÿLӇPEDQÿҫXYjWҥi thӡL ÿLӇPW$Yj$o Ojÿӝ hҩSWKөFӫa dung dӏch CV ӣ thӡLÿLӇPEDQÿҫXYjWҥi thӡLÿLӇP t
HiӋu suҩWSKkQKӫ\TXDQJKyDCV +ÿѭӧFWtQKWKHRF{QJWKӭc:
7URQJÿy&o Yj&OҫQOѭӧWOjQӗQJÿӝ ÿҫu cӫa CV YjQӗQJÿӝ FzQOҥi cӫa CV
1Kѭÿѭӧc thӇ hiӋQWURQJ+uQK&9NK{QJEӏ SKkQKӫ\NKLNK{QJFyFKҩt [~FWiFWURQJJLӡ chiӃu xҥ iQKViQJ/('ÿLӅXQj\FKRWKҩy sӵ quang pKkQWUӵc tiӃp cӫD&9OjNK{QJÿiQJNӇ &iFPүXÿѭӧc tәng hӧp ӣ FiFQKLӋWÿӝ NKiFQKDX Ƞ C;
120 Ƞ C; 140 Ƞ C; 160 Ƞ C; 180 Ƞ C; 200 Ƞ C, ta thҩy hiӋu suҩt xӱ Oê&9Fӫa mүu vұt liӋu BVO_140 cao nhҩW ÿҥt 98%, hiӋu suҩt xӱ Oê &9 WKҩp tҥL FiF Pүu BVO_100, BVO_120, BVO_160, BVO_180 Yj%92BJҫQQKѭQKDXFKӍ ÿҥt 70 - 80% ĈLӅu Qj\FyWKӇ thҩy rҵng ӣ nhiӋWÿӝ < 140 Ƞ &TXiWUuQKKuQKWKjQKQrQPҥQJOѭӟLY{Fѫ chұPWURQJNKLÿyQKLӋWÿӝ cao > 140 Ƞ &YѭӧWTXDÿLӇPKyDÿөFNpRWKHRÿyOjTXiWUuQKED\KѫLQѭӟc mҥnh Yjkeo tө chҩt hoҥWÿӝng bӅ mһt dүQÿӃn sӵ WKD\ÿәi cӫa WKjQKSKҫQJHOYjFҩXWU~F GRÿyNKyKuQKWKjQKYұt liӋXFyFҩXWU~FFyÿӝ trұt tӵ cao QrQGLӋQWtFKEӅ mһWYjNtFKWKѭӟc mao quҧQÿӅu giҧPÿHPOҥi hiӋu suҩt xӱ OêJLҧm, ÿӗng thӡLNKLWăQJQKLӋWÿӝ FNJQJOjPWăQJQăQJOѭӧng chuyӇQÿӝng Brown dүQÿӃn khҧ QăQJWӵ tә hӧp cӫa hӧp chҩWOjPWăQJFKLӅXGjLFӫa chuӛi kӷ QѭӟFOj\Ӄu tӕ quyӃt ÿӏQKÿӃQNtFKWKѭӟc mao quҧn cӫa vұt liӋu
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+uQK.7 HoҥWWtQKTXDQJ[~FWiFFӫDFiFPүXWURQJSKkQKӫy CV
BiӇXÿӗ EiQ ORRJDULWKyDFӫa nӗQJÿӝ EDQÿҫu so vӟi thӡi gian chiӃu xҥ Oj tuyӃQWtQKELӇu thӏ ÿӝng hӑc bұc mӝt 7KtQJKLӋPÿѭӧc lһp lҥi vӟLFiFPүu vұt liӋu NKiFQKDXWҥi nӗQJÿӝ 20 ppm vӟi thӡLJLDQSK~W7ӕFÿӝ EDQÿҫu cho mӛi mүu vұt liӋXÿѭӧF[iFÿӏnh tӯ hҵng sӕ tӕFÿӝ bұc mӝWYjQӗQJÿӝ EDQÿҫu Dӳ liӋXVDXÿy ÿѭӧFÿѭDYjRP{KuQKWӕFÿӝ ÿӝng hӑc Langmuir ± +LQVKHOZRRGÿmÿѭӧFiSGөng cho tӕFÿӝ SKiKӫ\TXDQJ[~FWiFEDQÿҫu cӫa nhiӅu hӧp chҩt hӳXFѫÿѭӧFP{Wҧ theo F{QJWKӭc [72]:
7URQJÿy&OjQӗQJÿӝ tҥi thӡLÿLӇPW&ROjQӗQJÿӝ EDQÿҫXNOjKҵng sӕ tӕc ÿӝ phҧn ӭng
4XDÿyÿѭӡng biӇu diӉn ln(CȠ/C) theo thӡLJLDQOjÿѭӡng thҷQJYjKӋ sӕ JyF FKtQKOjKҵng sӕ tӕFÿӝ biӇu diӉQNSK~W -1 ÿѭӧc thӇ hiӋQTXDKuQK.8A YjÿѭӧFWyP tҳt trong bҧng 4.5 Mүu BVO_140 vӟi hҵng sӕ tӕFÿӝ k = 11.36 x10 -3 SK~W -1 FDRKѫQ
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3*676%L;XkQ7KjQK so vӟLFiFPүXFzQOҥLYjKӋ sӕ WѭѫQJTXDQJ5 2 = 0.97936 Sӵ SKkQKӫy nӗQJÿӝ CV ÿӕi vӟi mүu BVO_140 ÿmÿѭӧFTXDQViWWKrPTXDELӇXÿӗ hҩSWKXÿREҵQJPi\89- Vis vӟLEѭӟFVyQJWӯ Ȝ BQPYjFѭӡQJÿӝ hҩp thө tҥLÿӍnh hҩp thө cӵFÿҥi ȜFӵFÿҥi = 580nm) giҧm dҫn cho thҩy sӵ suy giҧm tӯQJEѭӟc cӫa CV ÿѭӧc thӇ hiӋn TXDKuQK.8B
+uQK.9 Phә hҩp thu UV-Vis trong CV cӫa mүu vұt liӋu BVO_140
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+uQK.10 0jXVDXNKL[ӱ OêFӫa mүu vұt liӋu BVO_140
Bҧng 4.6 Bҧng thӕQJNrKҵng sӕ tӕc ÿӝ NYjKӋ sӕ WѭѫQJTXDQR 2
4.3.2 KӃt quҧ khҧo ViWQӗQJÿӝ cӫa dung dӏch Crytal Violet
KhҧRViWҧQKKѭӣng cӫa nӗQJÿӝ ÿӃn hiӋu quҧ [~FWiFTXDQJEҵng viӋc thay ÿәi nӗQJÿӝ &9EDQÿҫu (5, 10, 20, 30, 40SSPYjYүn giӳ QJX\rQOѭӧng chҩW[~FWiF OjJYӟi thӡi gian chiӃXViQJOjJLӡ +uQK.11 WUuQKEj\ҧQKKѭӣng cӫa nӗng ÿӝ WUrQKLӋu quҧ loҥi bӓ PjXFU\WDOYLROHWVӱ dөng vұt liӋu BVO_140 Sӵ SKkQKӫy QKDQKFKyQJFӫDPjXFU\WDOYLROHWOrQWUrQYұt liӋu BVO_140 ÿѭӧFTXDQViWWURQJ YzQJ60 SK~W chiӃXViQJ Cho thӡi gian tiӃS[~FGjLKѫQSKҫQWUăPSKkQKӫy thay ÿәLNK{QJÿiQJNӇ tҥi nӗQJÿӝ PjXcrytal violet EDQÿҫu cӫDSSPSSPYjSSP
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DӵDWKHRÿyVӵ SKkQKӫy tӕi da cӫDPjXcrytal violet WKuÿҥWÿѭӧc tҥi 90% cho 20ppm Yj>90FKRSSPYj0ppm Khi nӗQJÿӝ WăQJOrQSSPYj0ppm, phҫQWUăP SKkQKӫy giҧPÿӃn khoҧng 42% tҥi 40ppm, 62% tҥi 30ppm Cho thҩy rҵng tӕFÿӝ SKkQKӫ\TXDQJKyDOLrQTXDQÿӃn sӵ KuQKWKjQKJӕc x 2+WUrQEӅ mһt chҩW[~FWiFYj khҧ QăQJSKҧn ӭng giӳa gӕc x OH vӟi chҩWPjX1ӗQJÿӝ &9EDQÿҫXWăQJNpRWKHR mӝWOѭӧng lӟn CV hҩp phө WUrQFiFWkPKRҥWÿӝng bӅ mһt cӫa chҩW[~FWiFGRÿyVӵ hҩp phө cӫDFiFion hydroxyl (OH - WUrQFQJVӕ WkPKӑaWÿӝQJQj\JLҧmQJKƭDOj tӕFÿӝ KuQKWKjQKFiFJӕc x 2+WiFQKkQR[LKyDFKtQKFҫn thiӃt cho viӋFJLDWăQJKLӋu suҩWSKkQKӫy quang giҧPWKHR7KHRÿӏnh luұt Beer-Lambert, khi nӗng ÿӝ chҩWPjX WăQJFKLӅXGjLÿѭӡng dүQFiFSKRWRQYjRWURQJGXQJGӏch giҧPYjFiFSKRWRQFyWKӇ bӏ chҳQWUѭӟc khi tiӃQÿӃn bӅ mһW[~FWiFGRÿyVӵ hҩp thө photon cӫa chҩW[~FWiF giҧPÿLGүQÿӃn sӵ SKkQKӫ\TXDQJKyDJLҧm [73][74][75]
+uQK.11 KӃt quҧ khҧRViWQӗQJÿӝ cӫa dung dӏch Crytal Violet cӫa mүu
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4.3.3 KӃt quҧ khҧRViWKjPOѭӧng vұt liӋu [~FWiF
KhҧRViWҧQKKѭӣng cӫa KjP Oѭӧng vұt liӋX[~FWiF ÿӃn hiӋu quҧ [~FWiFTXDQJ bҵng viӋFWKD\ÿәi KjPOѭӧng chҩW[~FWiF (30, 40, 50, 60, 70mg) tҥi nӗQJÿӝ CV NK{QJÿәLOjSSPÿѭӧFWUuQKEj\WURQJKuQK.12 PhҫQWUăPSKkQKӫy WăQJWӯ 80% ÿӃn 99% cӫa PjXcrystal YLROHWWѭѫQJӭng vӟLOѭӧng chҩt [~FWiF WăQJWӯ 30mg g/l ÿӃn 70mJOĈLӅXQj\FKRWKҩ\Oѭӧng chҩt [~FWiF FjQJWăQJWKuSKҫQWUăPORҥi bӓ FjQJFDRSӵ JLDWăQJKLӋu suҩWSKkQKӫy cӫa thuӕc nhuӝPFyWKӇ ÿѭӧFFKROjGRVӵ sҹQFyFӫDFiFOӛ trӕng quang sinh nhiӅXKѫQÿѭӧc cung cҩp bӣLKjPOѭӧng chҩW[~FWiF FDRKѫQ
KӃt quҧ ÿiQKJLiKRҥWWtQKTXDQJKyDFӫa vұt liӋXFRPSRVLWHWUrQQӅn BiVO 4
Trong luұQYăQQj\QJKLrQFӭu hiӋu suҩWTXDQJ[~FWiFFӫa vұt liӋu tәng hӧp NiFe2O4/BiVO4 FQJYӟi NiFe2O4 Yj%L924 WK{QJTXDVӵ SKkQKӫ\TXDQJ5K%Gѭӟi chiӃu xҥ iQKViQJ/('ÿѭӧc thӇ hiӋQWURQJKuQK
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+uQK.13 HoҥWWtQK[~FWiFFӫa vұt liӋu nano NiFe2O4, BiVO4 Yj1iFe2O4/BiVO4
1Kѭÿѭӧc thӇ hiӋn trong huQK4.13 RhB NK{QJ bӏ SKkQKӫ\NKLNK{QJFyFKҩt [~FWiFWURQJJLӡ chiӃu xҥ iQKViQJ/('ÿLӅXQj\FKRWKҩy sӵ TXDQJSKkQWUӵc tiӃp cӫD5K%OjNK{QJÿiQJNӇ PhҫQWUăPNKӕLOѭӧng NiFe2O4 ҧQKKѭӣng lӟQÿӃQWKjQK phҫQYjFҩXWU~FFӫa vұt liӋu NiFe2O4/BiVO4 1KѭWKӇ hiӋn trong huQK4.13, vұt liӋu tәng hӧp NiFe2O4/BiVO4 cho thҩy hoҥW WtQK TXDQJ [~F WiF FDR KѫQ QKLӅu so vӟi NiFe2O4 YjBiVO4 WUѫ, cho thҩy rҵng sӵ kӃt hӧp cӫDFiFKҥt nano NiFe2O4 FyWKӇ WăQg Fѭӡng hoҥWÿӝng cӫa chҩW[~FWiFTXDQJBiVO4 Khi phҫQWUăP1L)H2O4 WăQJWӯ 5 % ÿӃn 20 % hiӋu suҩt xӱ Oê5K%WăQJWӯ ÿӃQ1KѭQJNKLWăQJSKҫQWUăP NiFe2O4 lӟQKѫQWKuKLӋu suҩt xӱ Oê5K%JLҧm KӃt quҧ Qj\cho thҩy hoҥWWtQK [~FWiFTXDQJ WăQJNKLWăQJOѭӧng NiFe pha tҥSYjKLӋu suҩWSKkQKӫ\ÿҥWÿѭӧc cao nhҩt ӭng vӟi tӍ lӋ1L)H%LOj&yWKӇ1L)H2O4 SKkQWiQWUrQEӅPһt BiVO4ÿm ÿyQJYDLWUzKҩSWKөQăQJOѭӧng bӭc xҥ khҧ kiӃQYjFiFÿLӋQWӱTXDQJVLQKWҥRWKjQK ÿѭӧFFKX\ӇQÿӃn BiVO4ÿӇWKӵc hiӋQFiFSKҧn ӭQJSKkQKӫ\5K%ĈLӅXQj\GүQÿӃn sӵ SKkQWiFKKLӋu quҧ FiFÿLӋQWӱYjOӛWUӕQJTXDQJVLQKWK{QJTXDPһt tiӃS[~FJLӳD BiVO4 Yj1L)H2O4GRÿyOjPJLҧm tӕFÿӝ WiLNӃt hӧSÿLӋQWӱ±OӛWUӕQJ7X\QKLrQ NKLOѭӧng NiFe pha tҥp lӟQKѫQWKuFiFSKkQWӱ1L)H2O4 lҥi trӣ WKjQKFiFWkP
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WiLNӃt hӧSÿLӋQWӱ±OӛWUӕQJĈӝ Gj\Fӫa lӟSÿLӋQWtFKNK{QJJLDQJLҧPNKLWăQJQӗng ÿӝ cӫa NiFe2O4 pha tҥSYjNKLJLiWUӏQj\QKӓKѫQVRYӟLÿӝVkXWKҭPWKҩu cӫDiQK ViQJYjRWURQJ%LVO4WKuVӵ WiLNӃt hӧp cһSÿLӋQWӱ±OӛWUӕng dӉ GjQJKѫQYjGRÿy hoҥWWtQK[~FWiFTXDQJJLҧPÿL[76]1JRjLUDYӟi mӝWOѭӧng lӟn NiFe2O4 tӗn tҥL WUrQEӅPһt BiVO4 WKuFiFÿLӋQWӱYjOӛWUӕQJÿѭӧc tҥRUDWӯ1L)H2O4 dӉ GjQJWiLNӃt hӧp vӟL QKDX WUѭӟF NKL FiF ÿLӋQ Wӱ GL FKX\ӇQ ÿӃn mһt tiӃS JLiS JLӳD 1L)H2O4 Yj BiVO4Ĉӗng thӡLWăQJOѭӧng NiFe pha tҥSÿӗQJQJKƭDYӟi viӋc tҥo ra sӵ che phӫ FiFWkPKRҥWÿӝng cӫa BiVO4, tӭFOjOjPJLҧm phҫQEӅPһt BiVO4 tiӃS[~FYӟi RhB, YjGRÿyFҧn trӣ phҧn ӭng cӫa RhB vӟLFiFJӕc hydroxyl [77]
+uQK4.14 Sӵ suy giҧPÿӝng hӑc ln(&Ƞ&WKHRP{KuQKÿӝng hӑc bұc mӝt (A), phә hҩp thu UV-9LVWURQJSKkQKӫy RhB cӫa mүu vұt liӋu NiFe2O4/BiVO4 (B) Ĉӝng hӑc suy giҧPWK{QJTXDOQ&Ƞ / C) so vӟi thӡi gian chiӃu xҥ sӱ dөng tӕc ÿӝ phҧn ӭng bұc mӝt giҧ FKR5K%ÿѭӧFWUuQKEj\WURQJ+uQK4.14A 7KtQJKLӋPÿѭӧc lһp lҥi vӟLFiFPүu vұt liӋXNKiFQKDXWҥi nӗQJÿӝ 10 -5 M vӟi thӡi gian 360 SK~W7ӕc ÿӝ EDQÿҫu cho mӛi mүu vұt liӋXÿѭӧF[iFÿӏnh tӯ hҵng sӕ tӕFÿӝ bұc mӝWYjQӗng
Lu̵QYăQWK̩FVƭ CBHD: TS Nguy͍n Duy Trinh
3*676%L;XkQ7KjQK ÿӝ EDQ ÿҫu Dӳ liӋX VDX ÿy ÿѭӧF ÿѭD YjR P{ KuQK WӕF ÿӝ ÿӝng hӑc Langmuir ± Hinshelwood Hҵng sӕ tӕF ÿӝ biӇu kiӃn (k app, min -1 ) cӫa hӧp chҩt 20% NiFe2O4/BiVO4 ÿӕi vӟi sӵ SKkQKӫ\5K%Ojợ -3 SK~W -1 FDRKѫQKDLOҫn so vӟi BiVO4 tinh khiӃt Sӵ NKiFELӋt vӅ JLiWUӏ kapp giӳa hӧp chҩt NiFe2O4/BiVO4 YjBiVO4 tinh khiӃt FyWKӇ OLrQTXDQÿӃn cҩu WU~FSKkQWӱ YjFѫFKӃ SKkQKӫy cӫDFK~QJ+uQK4.14B thӇ hiӋn sӵ SKiWWULӇn theo thӡi gian cӫa phә hҩp thө khi hҩp phө YjYӟi iQKViQJWUҳQJ/('WUrQYұt liӋu nano NiFe2O4/BiVO4&kQEҵng hҩp phө / giҧi hҩp phө giӳDFiFSKkQWӱ 5K%YjEӅ mһt NiFe2O4/BiVO4 ÿҥWÿѭӧc sau 1 giӡ khuҩy trong EyQJWӕL7URQJTXiWUuQKFKLӃu xҥ, dҧi hҩp phө UV-vis rӝng 554 nm giҧm dҫQYj ÿӍQKQj\Gӏch chuyӇn dҫQVDQJEѭӟFVyQJQJҳQKѫQcho thҩy sӵ suy giҧm tӯQJEѭӟc cӫa RhB
Lu̵QYăQWK̩FVƭ CBHD: TS Nguy͍n Duy Trinh
Trong luұQYăQQj\Yұt liӋX[~FWiFTXDQJBiVO4 Yj NiFe2O4/BiVO4 ÿѭӧc tәng hӧS WKjQK F{QJ EҵQJ SKѭѫQJ SKiS WKӫy nhiӋW ÿm Wҥo ra vұt liӋX Fy KRҥW WtQK TXDQJ[~FWiFÿѭӧc cҧi thiӋQÿiQJNӇ WURQJSKkQKӫy chҩWPjXKӳXFѫ5K% Yj&9
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+RҥWWtQK[~FWiFTXDQJKyDWURQJFӫDYұWOLӋXWURQJSKkQKӫ\FKҩWPjXKӳu Fѫ5K%GѭӟLiQKViQJQKuQWKҩ\ӣ mүu 20% NiFe2O4/BiVO4 FyNKҧ QăQJSKkQKӫy RhB tӕt nhҩt so vӟLFiFPүu vұt liӋXNKiFSKkQKӫ\KRjQWRjQPjX5K%WUong 6 giӡ Gѭӟi chiӃXiQKViQJÿqQ/('Yӟi hiӋu suҩWÿҥWWѭѫQJӭng vӟLN ௗợ -
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Lu̵QYăQWK̩FVƭ CBHD: TS Nguy͍n Duy Trinh
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Lu̵QYăQWK̩FVƭ CBHD: TS Nguy͍n Duy Trinh
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