Current progress on 3D graphene-based photocatalysts: From synthesis to photocatalytic hydrogen production

Hydrogen (H₂) is considered an alternative energy carrier for future clean energy systems in many applications. The three-dimensional (3D) graphene is one of the promising candidates for various applications especially in photocatalytic H₂ production due to its high electron conductivity, mechanical stability, fast electron transfer, and large surface area. Exploring the changes in the physical properties from different dimensionalities can be interesting because a 3D structure may improve the photocatalytic efficiency in terms of enhancing the light adsorption, increasing the accessible active surface, and improving the charge transport. Graphene can act as an electron acceptor and cocatalyst, and combining the graphene with metal oxides, transition metal dichalcogenides, or other semiconducting materials can enhance the photocatalytic activity of composites. Therefore, the synthesis, characterization, mechanism, and performance of the 3D graphene-based photocatalyst in the photocatalytic H₂ production are comprehensively discussed. The current progress and future challenges in the H₂ generation is also discussed in this review.