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

In the present work, the WS 2 nanosheets were prepared through a liquid-phase exfoliation method (LPE). Various techniques were then used to characterize thickness, length, and concentration of these nanosheets. WS 2 nanosheets were also loaded on α–Fe 2 O 3 photoanodes to prepare core-shell structured α–Fe 2 O 3 /WS 2 /WO x photoanodes. These core-shell structured α–Fe 2 O 3 /WS 2 /WO x 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–Fe 2 O 3 /#4-WS 2 /WO x ) had photocurrent densities of 0.98 and 2.1 mA cm −2 (with the lowest onset potential 0.54 V RHE and 0.47 V RHE ) under front and back-side illumination, respectively, at 1.23 V RHE under 100 mW cm −2 , which were about 13 and 30-fold higher than those of pure α-Fe 2 O 3 photoelectrode. Furthermore, H 2 and O 2 production of α–Fe 2 O 3 /#4-WS 2 /WO x photoanode were 32 μmol.cm −2 and 15.3 μmol.cm −2 , respectively at 1.23 V RHE under 100 mW cm −2 after 2 h. • The amount of WS 2 nanosheets was estimated to optimize the concentration and thickness. • Depth, surface, and interface of the α–Fe 2 O 3 /#4-WS 2 /WO x report by TOF-SIMS analysis. • A developed model for MS plots was investigated for cylindrical geometry of nanorods. • The best W SCL value of the α–Fe 2 O 3 /#4-WS 2 /WO x decreased 54% that of the pure α–Fe 2 O 3 . • The H 2 and O 2 evolution of α–Fe 2 O 3 /#4-WS 2 /WO x obtained 32 and 15.3 μmol cm −2 , respectively.