International Journal of Hydrogen Energy, Vol.45, No.16, 9635-9647, 2020
Carbon membrane bridged ZnSe and TiO2 nanotube arrays: Fabrication and promising application in photoelectrochemical water splitting
In this work, a cascade structure among ZnSe, carbon membrane and TiO2 NTAs was constructed precisely. This carbon membrane bridged ZnSe and TiO2 composite exhibits excellent H-2 evolution activity, the H-2 evolution rate of ZnSe/C/TiO2 NTAs (866.76 mu mol/cm(2)) is about 6.95 times higher than that of pure TiO2 NTAs (124.64 mu mol/cm(2)) after 200 min irradiation. The introduction of carbon membrane can greatly facilitate the electron transfer from ZnSe to TiO2, ZnSe/C/TiO2 ternary composite exhibits the highest transient photocurrent density (1.05 mA/cm(2)) and the lowest impedance (677.6 Omega) among all the samples. Besides, the contact between TiO2 and electrolyte is improved after introducing carbon membrane, therefore C/TiO2 NTAs shows more positive flat band potential of (1.86 V) compared with TiO2 NTAs (0.50 V). It is also found that pure carbon powder can achieve H-2 production under visible light irradiation, its sensitization effect can further improve photocurrent density of the composite under 500 nm light radiation, the electrons produced in carbon film can inject into TiO2, and holes from TiO2 can quickly transfer to carbon film, leading to excellent H-2 evolution efficiency. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.