VNU Journal of Science Mathematics – Physics, Vol 37, No 4 (2021) 38 50 38 Original Article Enhanced Photocatalytic Activity Using Near Visible Light of ZnO Nanorods by Doping with Mn2+ Ions Luong Hoai Nhan1, Nguyen Huu Khoa1, Lai Thi Ngoc Huyen1, Huynh Hung Quang1, Dinh Tan Muon1, Nguyen Ngoc Phuong4, Tran Cong Khanh1,2, Phan Bach Thang1,2,3, Dang Vinh Quang1,2,3,* 1Department of Materials Science and Technology, University of Science, Nguyen Van Cu, District 5, Ho Chi Minh City, Vietnam 2Vietn[.]