Progress and challenges on reduced graphene (rGO)-based Co-catalysts for efficient photocatalytic hydrogen production via water splitting

Reduced graphene oxide (rGO) exhibits highly adjustable electronic properties owing to their unique two-dimensional carbon structure, facilitating extensive surface modifications. Photocatalytic water splitting relies on semiconducting materials possessing electronic structures conducive for charge carriers to reach the surface of the photocatalyst to participate in the water splitting reactions. Numerous efforts have been made to establish viable photocatalytic systems capable of efficiently separating water into hydrogen gas and oxygen solely through solar energy input, specifically visible light. Notably, the integration of rGO with a suitable semiconductor photocatalyst has been reviewed extensively with much emphasis on electronic properties, stability and surface area of the rGO. This paper highlights several key findings and draws attention to potential future directions that can contribute to unlocking the full potential of rGO in photocatalytic hydrogen production through careful examination of the significant role that rGO plays in enhancing photocatalytic hydrogen (H₂) production when integrated with various semiconductor photocatalysts.