Efficient and stable core-shell α?Fe2O3/WS2/WOx photoanode for oxygen evolution reaction to enhance photoelectrochemical water splitting

Abstract

In the present work, the WS2 nanosheets were prepared through a liquid-phase exfoliation method (LPE). Various techniques were then used to characterize thickness, length, and concentration of these nanosheets. WS2 nanosheets were also loaded on α–Fe2O3 photoanodes to prepare core-shell structured α–Fe2O3/WS2/WOx photoanodes. These core-shell structured α–Fe2O3/WS2/WOx nanorods have advantages of effective separation, decreased recombination of photo-generated electron-hole pairs, and increased electron transport properties, resulting in improved PEC performance. The best photoanode (α–Fe2O3/#4-WS2/WOx) had photocurrent densities of 0.98 and 2.1 mA cm-2 (with the lowest onset potential 0.54 VRHE and 0.47 VRHE) under front and backside illumination, respectively, at 1.23 VRHE under 100 mW cm-2, which were about 13 and 30-fold higher than those of pure α-Fe2O3 photoelectrode. Furthermore, H2 and O2 production of α–Fe2O3/#4-WS2/WOx photoanode were 32 μmol.cm-2 and 15.3 μmol.cm-2, respectively at 1.23 VRHE under 100 mW cm-2 after 2 h.