Highly porous nanofiber of bismuth sulfide/poly-o-aminobenzenethiol-bismuth tungstate composite seeded on poly-1H pyrrole: Photocathode for green hydrogen generation without external sacrificing agent

Abstract

A novel and highly porous nanofiber composite, Bi₂S₃–poly(O-aminobenzenethiol)/Bi₂WO₆ (Bi₂S₃–POABT/Bi₂WO₆ NF), was successfully synthesized via in-situ polymerization of O-aminobenzenethiol in the presence of Bi₂WO₆. The resulting nanofibers, with an average diameter of approximately 40 nm, provide abundant active sites for efficient photon absorption and hot electron generation. To fabricate an efficient photocathode, the Bi₂S₃–POABT/Bi₂WO₆ NF composite was integrated onto poly(1H-pyrrole) (P1HP), forming a hybrid Bi₂S₃–POABT/Bi₂WO₆ NF/P1HP photocathode. This photocathode demonstrated excellent photoelectrochemical performance for hydrogen production from both natural Red Sea water and laboratory-prepared artificial seawater. The measured photocurrent densities (J_ph) were −0.70 and −0.66 mA/cm² for natural and artificial seawater, respectively. Notably, the system produced 0.24 mmol/h of hydrogen over a 10 cm² photocathode area using natural seawater under illumination. Further analysis revealed that the photocathode exhibited strong photoresponse sensitivity to incident photon energy, with peak J_ph values of −0.67 and −0.61 mA/cm² at photon energies of 3.6 and 2.8 eV, respectively. These results highlight the promising potential of the Bi₂S₃–POABT/Bi₂WO₆/P1HP photocathode for sustainable hydrogen production. Its high efficiency, simple synthesis method, and compatibility with real seawater make it a viable candidate for practical solar-driven water-splitting applications.