Enhanced photoelectrochemical hydrogen production by a composite photoanode constructed with TiO2 nanorods and Cu-modified NH2-MIL-125

It is of great interest to enhance the photoelectrochemical hydrogen production rate of TiO2 by utilizing the new Metal-organic frameworks material such as NH2-MIL-125(Ti), but the assembly method and its details often bring about a significant difference in performances of the composite photoelectrode. In this study, NH2-MIL-125 is grown on the surface of TiO2 nanorods by an in-situ strategy, and then Cu-modified NH2-MIL-125/TiO2 photoanode is prepared by impregnation method. Based on the characterization of SEM, UV-VIS DRS and PL spectra, the disc-like NH2-MIL-125 can improve the light absorptance in visible light region, and the modification of Cu+/Cu2+ can inhibit the charge recombination in NH2-MIL-125/TiO2 photoanode, resulting in the improved the carrier transport ability verified by EIS and IMPS. Under AM 1.5 illumination, H2 evolution rate over Cu-NH2-MIL-125/TiO2 is boosted a great extent, which is 4.6 times than that of pristine TiO2.