A High-Performance Sb₂S₃–Based Photocathode with rGO and TiO₂/Pt for Photoelectrochemical Water Splitting

Antimony sulfide (Sb 2 S 3 ) is an emerging semiconductor for photoelectrochemical (PEC) water splitting, but its low carrier concentration and susceptibility to corrosion limit its performance. Constructing heterojunctions is an effective strategy to address these challenges. This study presents a high-performance Sb 2 S 3 -based photocathode for PEC water splitting by incorporating reduced graphene oxide (rGO) to confine Sb 2 S 3 growth and TiO 2 /Pt to optimize the energy band alignment. The resulting photocathodes (Sb 2 S 3 -rGO/TiO 2 /Pt) exhibit a photocurrent density of −7.75 mA/cm 2, an onset potential of 0.70 V vs reversible hydrogen electrode, and an absorbed photocurrent efficiency of 0.71%, representing the highest performance reported for Sb 2 S 3 -based photocathodes that exclude toxic materials. The synergistic effects of rGO incorporation and heterojunction formation effectively promote charge separation and transport, significantly enhancing the PEC performance. This work provides a pathway for designing high-performance, environmentally friendly photocathodes based on Sb 2 S 3 for solar-driven hydrogen production, offering a nontoxic alternative to traditional photocathode materials.