Highly effective photoelectrochemical performance of solar energy materials based on Ag2WO4-AgX (X = Cl, Br, I) sensitized TiO2 nanotube arrays

The highly effective photoelectrochemical materials based on TiO2 nanotube arrays (TiO2 NTs) co-sensitized by Ag2WO4 and AgX (X = Cl, Br, I) were in-situ prepared by a successive ionic layer adsorption and reaction deposition of Ag2WO4 nanoparticles on TiO2 NTs followed by ion exchange to form Ag2WO4-AgX (X =Cl, Br, I) heterojunctions by a hydrothermal method. The deposition of Ag2WO4-AgX (X = Cl, Br, 1) nanoparticles was investigated by XRD and SEM. The Ag2WO4-AgX (X = Cl, Br, I) sensitization significantly extended the inherent UV absorption of TiO2 NTs to the visible light region. The photoelectrochemical properties including the visible light photocurrent response and photoelectrocatalytic removal of methyl orange, rhodamine B and Cr(VI) were investigated in detail. The results indicated the TiO2 NTs/Ag2WO4-AgBr photoelectrode showed the optimal photoelectrochemical properties, which could be attributed to the excellent energy band structure and interface conductance.