Effect of the conductive substrate on the photoelectrocatalytic properties of hematite for water splitting

In this paper, hematite photoanodes were prepared on F-doped SnO2 glass (FTO), polystyrene microspheres (PS), a three-dimensional conductive substrate prepared from a monolayer PS template (MM-TCS) and a bilayer PS template (B-TCS) by a hydrothermal method, and the effect of the different substrates on the photoelectrocatalytic (PEC) performance of hematite was investigated. At 1.23 V (vs RHE), the hematite photoanode prepared on B-TCS (B-TCS-hematite) has the optimal photocurrent response of 1.16 mA cm−2, which is 4.6 times that of the hematite photoanode prepared on FTO (FTO-hematite). The improved PEC performance of the B-TCS-hematite sample is mainly due to the thicker and more connected B-TCS layers, the high ratio of (1 0 4)/(1 1 0), the morphology of nanocoral rods with larger gaps and the increased light absorption, which significantly improve the bulk charge separation efficiency and surface charge injection efficiency. In this work, the effects of conductive substrates on the photoelectrocatalytic water of hematite were investigated by scanning electron microscopy (SEM), UV–vis spectroscopy, X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), and photoelectrical measurements.