2D TiO2/Ti3C2 conductive substrate enhanced the photoelectrochemical performance of hematite for water splitting

Abstract

Since the photoelectrochemical properties of hematite are affected by its bulk and surface charge recombination, the introduction of a conductive substrate is a feasible way to improve its properties. In this paper, the Ti3C2 and TiO2/Ti3C2 conductive substrates were prepared by electrophoretic depositing multilayered Ti3C2 and TiO2/Ti3C2 nanosheet powders onto F-doped SnO2 glass (FTO), respectively. Then, the TiO2/Ti3C2-hematite and Ti3C2-hematite photoanodes were obtained by in-situ growth of hematite on Ti3C2 and TiO2/Ti3C2 conductive substrates by hydrothermal method. The photoanodes were characterized by scanning electron microscopy (SEM), UV–vis spectroscopy, X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS) and photoelectrical measurements. The photocurrent density of TiO2/Ti3C2-hematite reaches 1.29 mA cm−2 at 1.23 V (vs. RHE), which is 3.7 times than that of the FTO-hematite as 0.35 mA cm−2. The enhancement of the photocurrent response of TiO2/Ti3C2-hematite is mainly due to the great improvement of the bulk charge separation efficiency and the surface charge injection efficiency. This is attributed to the fact that the layered TiO2/Ti3C2 conductive substrate can improve the interface property of FTO/hematite, provide Ti source and a larger specific surface area for the growth of hematite.