Boosting solar fuel production of bismuth ferrite thin film by incorporating reduced graphene oxide

In this study, a facile chemical approach was utilized to successfully fabricate a porous bismuth ferrite (BiFeO3, BFO)/reduced graphene oxide (rGO) nanocomposite thin film as a photoanode for photoelec-trochemical (PEC) water splitting. The BFO nanoparticles possess a pure rhombohedral distorted perovskite crystal structure and are grafted onto rGO nanosheets. BFO/rGO (BGO) thin film has smaller nanoparticles (around 100 nm) and higher porosity which provides a higher surface area compared to BFO. Moreover, BGO exhibits higher visible absorption, a narrower band gap energy of 1.95 eV, and a lower recombination rate of charge carriers. The BGO photoanode has a maximum photocurrent density of 0.451 mA.cm-2 at 1.23 V versus the reversible hydrogen electrode (RHE) under 100 mW.cm-2 illumination which is 2.5 times more than the BFO photoanode. The applied bias photon-to-current efficiency (ABPE) of BGO nanocomposite film is 0.21%, which is approximately 2.5 times that of BFO. The obtained results reveal an intimate hetero-structure between BFO nanoparticles and rGO nanosheets. The charge separation and transfer of BFO are significantly boosted by incorporating the rGO. This study sheds light on the mechanism insights of en-hanced PEC water splitting in BFO/rGO thin film, offering a new approach to the design and fabrication of high-efficiency photoanodes.(c) 2022 Elsevier B.V. All rights reserved.