Applied Catalysis A: General, Vol.521, 90-95, 2016
Design of visible light responsive photocatalysts for selective reduction of chlorinated organic compounds in water
Periodic density functional theory (DFT) calculations were performed for beta-Bi2O3 photocatalyst that was modified with 32 elements. Our focus was to design visible light responsive photocatalysts for selective reduction of chlorinated organic compounds (COCs) in water. The wanted photocatalysts should have (1) a moderate adsorption potential for COCs; (2) a wide adsorption spectrum for harvesting visible light; and (3) a reduction potential enough to destroy COCs. Based on these assumptions, a combined grand canonical Monte Carlo (GCMC) and molecular dynamics (MD) simulation study was used to investigate the adsorption and diffusion behaviors of COCs in 32 modified beta-Bi2O3 ; a Becke-three-parameter-Lee-Yand-Par (B3LYP) DFT method was used to calculate the energy band structures and redox potentials of different modified beta-Bi2O3 . Sequentially, these modified beta-Bi2O3 were synthesized by solvothermal method, and the photo-reactivity of them were quantified in terms of the conduction band (CB) electron reduction using pentachlorophenol (PCP), trichloroethylene (TCE), and gamma-hexachlorocyclohexane (HCH) as model COCs. The results demonstrated that the adsorption, photoabsorption, and photo-reactivity of modified beta-Bi2O3 appear to be a complex function of the periodicity of 32 doped elements, which can be explained by the structural changes on the crystalline form and energy band structure. Based on this principle, a series of competent photocatalysts were believed to be efficient on the reduction of COCs. We designed and synthesized: (1) Ti-beta-Bi2O3 photocatalyst that performed best on reduction of PCP (37.2 mu mol L-1) with apparent quantum yield (phi(PCP)) of 1.20%; (2) Sr-beta-Bi2O3 photocatalyst for TCE (76.2 mu mol L-1) reduction (phi(TCE) 1.03%); and, (3) Zr-beta-Bi2O3 photocatalyst for HCH (27.5 mol mu L-1) reduction (phi(HCH) 0.67%). (C) 2015 Elsevier B.V. All rights reserved.