Criss-crossed a-Fe2O3 nanorods/Bi2S3 heterojunction for enhanced photoelectrochemical water splitting

In this research work, alpha-Fe2O3/Bi2S3 heterojunction photoelectrodes for improved photoelectrochemical water splitting have been successfully fabricated on FTO substrate by applying hydrothermal and solvothermal approaches. A seed layer approach is also applied before the solvothermal step for the homogeneous distribution of Bi2S3 over alpha-Fe2O3 nanorods to obtain a uniform heterojunction. The physicochemical and optical techniques results of alpha-Fe2O3/Bi2S3 indicate high crystallinity, presence of two distant phases with different bandgap positions. Linear sweep voltammetry (LSV) results indicate that the optimized alpha-Fe2O3/Bi2S3 photoanode performs a maximum photocurrent density of 2.550 mA cm(-2) at 1.23 V-RHE which is almost 20 times higher than pristine alpha-Fe2O3 (0.123 mA cm(-2) at 1.23 V (RHE)). Electrochemical Impedance Spectroscopy (EIS) entirely shows alpha-Fe2O3/ Bi2S3.6 h is the lowest R-p (180.9 omega cm(2)) compare to pristine Fe2O3 (5810 omega cm(2)), indicating enhanced photo catalytic performance on OER and S2-/S-2(2-) cycle followed under 100 mW cm(-2) solar irradiation. This significant upsurge in the photocurrent density and applied biased photon-to-current conversion efficiency shown by the heterojunction is attributed to the improved light-harvesting efficiency, enhanced conductivity, and effective charge separation at the alpha-Fe2O3/Bi2S3 interface.