Controllable TiO2 heterostructure with carbon hybrid materials for enhanced photoelectrochemical performance

Abstract

In TiO₂ both advantages (stability and low cost) and disadvantages (large bandgap) coexist, so how to optimize a bare TiO₂ electrode is a continuous hot topic for the construction of suitable photoelectrochemical (PEC) devices based on TiO₂ for water splitting. This paper reports a facile and simple fabrication of a TiO₂/RGO/C₃N₄ photoelectrode for PEC splitting of water. Its heterostructure configuration has been characterized and confirmed by XRD, Raman spectroscopy, XPS, TEM and STEM. The introduction of both RGO and C₃N₄ film onto the surface of TiO₂ is mainly due to the fact that C₃N₄ has a strong photoelectric ability to respond to visible light and RGO plays an important role in the fast transfer of photogenerated charges across interfaces. Photocurrent and monochromatic incident photon-to-photocurrent efficiency (IPCE) of the titled heterostructure have been obviously improved, and the IPCE value (0.5 V vs. AgCl/Ag) of TiO₂/RGO/C₃N₄ was estimated to be up to 28% at a wavelength of 400 nm.