Eco-Friendly In₂S₃ Cocatalyst Assisted GaN Nanowires for Enhanced Solar-Driven Water Splitting

Considering ongoing research endeavors aimed at developing oxygen evolution cocatalysts (OECs), there is a growing sense of anticipation regarding the potential benefits of strategically integrating these OECs with photoanodes. Such an integration holds promise as a viable pathway to significantly enhance the efficiency of solar-assisted water splitting. However, despite considerable efforts directed toward improving the solar-to-hydrogen conversion efficiency of GaN-based photoanodes, there remains a need for further progress toward realizing the full potential of GaN as a promising photoanode material. In this study, we have successfully fabricated an advanced photoanode composed of nanostructured In2S3/ZnO/GaN. This novel photoanode demonstrates a substantial increase in photocurrent density, approximately 4.5 times greater (2.6 mA cm(-2)), compared to pristine GaN nanowires (GNW). This remarkable enhancement can be attributed to improved light absorption and rapid charge separation within the photoanode structure. Additionally, the incident photon-to-current efficiency reached an impressive 64%, a notable improvement over the efficiency of 32% observed in pristine GNWs. Further investigations into charge transfer resistance and carrier lifetime provide insights into the formation of a type-II heterojunction between In2S3 nanoparticles and GNWs, elucidating the underlying mechanisms responsible for these improvements. This study not only presents effective methodologies for advancing GaN-based photoanodes but also broadens the prospects for utilizing eco-friendly cocatalysts in the photocatalytic generation of hydrogen through solar water splitting processes.