SILAR preparation of visible-light-driven TiO2 NTs/Ag2WO4-AgI photoelectrodes for waste water treatment and photoelectric conversion

The preparation of novel visible-light-driven photoelectrodes is an effective strategy to solve the obstacles of environmental pollution and energy shortage. Here, the ternary semiconductor photoelectrode with high photoelectrochemical performances was designed by the successive ionic layer adsorption and reaction (SILAR) deposition of Ag2WO4-AgI nanoparticles on the surface of TiO2 nanotube arrays (TiO2 NTs/Ag2WO4-AgI). The synergistic sensitization of Ag2WO4-AgI benefited the improvement of the visible light absorption and electron separation. The results indicated that the TiO2 NTs/Ag2WO4-AgI photoelectrode showed excellent photoelectric convertion, and produced remarkable visible light photocurrent and photovoltage. Meanwhile, organic dyes (RhB, MO and MB) and heavy metal ions (Cr (VI)) could be rapidly removed by the ternary photocatalyst under solar irradiation. The effective electron transportation and low recombination were main reasons for the excellent photoelectrochemical property. This work describes the fruitful strategy for the design of highly active TiO2 NTs photoelectrode with siliver based semiconductor co-sensitization toward waste water treatment and photoelectric conversion.