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

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 Ti 3 C 2 and TiO 2 /Ti 3 C 2 conductive substrates were prepared by electrophoretic depositing multilayered Ti 3 C 2 and TiO 2 /Ti 3 C 2 nanosheet powders onto F-doped SnO 2 glass (FTO), respectively. Then, the TiO 2 /Ti 3 C 2 -hematite and Ti 3 C 2 -hematite photoanodes were obtained by in-situ growth of hematite on Ti 3 C 2 and TiO 2 /Ti 3 C 2 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 TiO 2 /Ti 3 C 2 -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 TiO 2 /Ti 3 C 2 -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 TiO 2 /Ti 3 C 2 conductive substrate can improve the interface property of FTO/hematite, provide Ti source and a larger specific surface area for the growth of hematite.