Fabrication and photoelectrochemical performance of Ag/AgBr sensitized TiO2 nanotube arrays for environmental and energy applications.

Graphical abstract Ag-AgBr microspheres were deposited on the surface of TiO 2 nanotube arrays by a solvothermal method. The visible light photocurrent density of TiO 2 NTs/Ag-AgBr (SH) was 5.86 mA/cm2, the photovoltage was −0.31 V/cm2, the flat band was −0.79 V, and the carrier concentration was 1.77 × 1020 cm−3. The TiO 2 NTs/Ag-AgBr (SH) showed the optimal photoelectrocatalytic removal efficiencies of methyl orange, rhodamine B, methyl blue and Cr(VI). Highlights • Ag-AgBr nanospheres were deposited on TiO 2 nanotube arrays by a hydrothermal method. • The TiO 2 NTs/Ag-AgBr (SH) photoelectrode showed the excellent photoelectrochemical properties. • The PEC mechanism of TiO 2 NTs/Ag-AgBr photocatalysts was proposed. Abstract The TiO 2 nanotube arrays (TiO 2 NTs) sensitized by Ag-AgBr nanoparticles were prepared with different alkali (sodium hydroxide, urea and methenamine) as mineralizers by a hydrothermal method, and the TiO 2 NTs/Ag-AgBr photoelectrode showed high visible light absorption, transient photocurrent and photoelectrocatalytic (PEC) performances. The results indicated that TiO 2 NTs/Ag-AgBr (SH) photoelectrode showed the high visible light photocurrent density of 5.86 mA/cm2, photovoltage of −0.31 V/cm2 and PEC removal efficiency for MO (71.97%), RhB (59.88%), MB (80.76%) and Cr(VI) (52.24%), respectively. The high PEC property could be attributed to the high activities of solar absorption and electron separation. The excellent photoelectrochemical property of TiO 2 NTs/Ag-AgBr would induce the novel photoelectrode promising applications in solar cells and wastewater treatment. [ABSTRACT FROM AUTHOR]