Enhanced photoelectrocatalytic performance of ZnIn 2 S 4 modified TiO 2 nanotube array toward methylene blue

Environmental pollution caused by organic pollutants has been attracted more and more attention by the researchers. In this paper, ZnIn 2 S 4 modified TiO 2 nanotube array (ZnIn 2 S 4 /TiO 2 ) composite electrodes are prepared by loading chalcogenide semiconductor material ZnIn 2 S 4 on the surface of TiO 2 nanotube array (TiO 2 NTA) for the degradation of methylene blue (MB). The physicochemical properties of ZnIn 2 S 4 /TiO 2 composite electrodes are analyzed by X-ray photoelectron spectroscopy, X-ray diffraction, photoluminescence spectroscopy and so on. The photoelectrocatalytic degradation rate of ZnIn 2 S 4 /TiO 2 composite electrode with the concentration of ZnIn 2 S 4 as 0.5 mmol/L (ZISTO-2) reaches 93.3% under the bias voltage of 0.7 V and simulated sunlight irradiation for 180 min against MB, which is 22.44% higher than that of pure TiO 2 NTA electrode, and the degradation rate of ZISTO-2 composite electrode toward MB is maintained at 78.2% after five cycles. The radical trapping experiments indicate that h + , ·O 2− and ·OH has significant contribution in the photoelectrocatalytic degradation. This paper provides a new ideal way to solve the problem of water pollution under visible light.