preparation of hexagonal wo3 from hexagonal ammonium tungsten bronze for sensing nh3

... Preparation of hexagonal WO 3 from hexagonal ammonium tungsten bronze for sensing NH 3 Imre Miklo ´ s Szila ´ gyi a, * , Lisheng Wang b , ... were not tested and it was still unknown whether thermal annealing of ammonium polytungstates and hexagonal ammonium tungsten bronzes could yield nanosize h-WO 3 . Materials Research Bulletin ... properties ABSTRACT Hexago...

Ngày tải lên: 20/03/2014, 13:06

... for 0.1% (1 mgÆmL )1 ) solution of 1.79 for Tma-RNase HI, 1.75 for Tma-CD, 1.85 for Tma-ND, 1.58 for Tma-W22A, 2.0 for Eco-RNase HI, 0.97 for Sto-RNase HI and 0.56 for Tk-RNase HII. These values ... 0.05–1.5 lm for Tma-RNase HI, 10– 50 lm for Tma-CD, 1.0–10 lm for Tma-ND and 0.5–50 lm for Tma-W22A. From the plot of the equilibrium binding responses as a function...

Ngày tải lên: 06/03/2014, 22:21

... find the way for increasing K 1 of hexagonal ferrite mainly by substitution effects. The second term in (1) dealing with shape anisotropy of particles forming material and takes part of several ... could reach the value of 10 5 A/m and K 1 = 5.10 6 J/m 3 . Thus with the simultaneous substitution of La for Sr and Co for Fe in the SrM-ferrite hard magnetic properties o...

Ngày tải lên: 13/02/2014, 03:20

... lengths in Fig. 1b range from 150 to 250 nm and their diameters vary from 5 to 50 nm. A calculation of the particle size dis- tribution of these samples shows that more than 85% of the tungsten oxide rods ... high yield of multiwalled WS 2 nanotubes. 2. Experimental 2.1. Synthesis of WO 3 nanorods An aqueous solution containing a mixture of 1.32 g of (NH 4 ) 10 W 12 O 41 ·...

Ngày tải lên: 19/03/2014, 16:48

... electrochemical performance of thin films have been determined by atomic force microscopy and cyclic voltammetry. The ion insertion properties of tungsten oxide hydrate and tungsten oxide films ... Lately, tungsten oxides have been commonly applied as sensing layers for hazardous gas detection as well. In this work, a soft chemical nanocrystalline processing route has been demonst...

Ngày tải lên: 20/03/2014, 13:05

... oxy- gen vacancies [2]. Among of other candidates, tungsten oxides have been commonly applied as sensing layers for hazardous gas detection [3,4]. Various crystalline forms of tungsten oxides can be ... properties of the hex-WO 3 and hybrid hex-WO 3 /MWCNTs composites were tested in the presence of very low concentra- tions of NO 2 (nitrogen dioxide). 2. Experimental 2.1. P...

Ngày tải lên: 20/03/2014, 13:05

... Among early TMOs, those with metals in formal oxidation states of five or six – e.g., oxides of W, M, and V – show high activity for many chemical transformations. As an example, supported WO x activity ... species subliming from solid WO 3 are oligomers of tungsten trioxide, i.e., (WO 3 ) x ,2 x 8. Among the oligomers, x = 3 predominates by an order of magnitude. Based on the fo...

Ngày tải lên: 20/03/2014, 13:06

... control the suspension from a standpoint of gas sensor applications. In the present study, we examined the possibilities of obtaining aqueous sols of WO 3 Á2H 2 O from an aqueous solution of Na 2 WO 4 by ... and properties of the acidification products. This paper aims at reporting the ion-exchange based preparation of WO 3 Á2H 2 O sols from Na 2 WO 4 . Formation and charac...

Ngày tải lên: 20/03/2014, 13:06

... sub- strates by resistive heating of a tungsten filament under an oxygen atmosphere at a low pressure. A schematic diagram of the apparatus used for the formation of WO 3 nanoparticles is shown in ... the formation of metal-oxide nanoparticles, such as WO 3 , MoO 3 , etc.; they evaporated various metals in Ar and O 2 mixture. The first application of the gas evaporation to the for...

Ngày tải lên: 20/03/2014, 13:06

Ngày tải lên: 23/09/2012, 14:47