Recent advances in photocatalytic carbon-based materials for enhanced water splitting under visible-light irradiation

Hydrogen production through photocatalytic water splitting under visible-light irradiation is an appealing approach to generate clean and economical renewable energy resources. The key challenge in this field of research is to design and engineer cost-effective, green, and efficient photocatalysts. Recently, carbon-based photocatalysts have attracted huge interest for visible-light-driven hydrogen evolution reactions due to their high chemical stability, excellent electrical conductivity, and tunable surface characteristics. Here, a critical review on how various carbon-based materials such as carbon nitride, conjugated polymers, metal-organic frameworks, functionalized carbon quantum dots, and graphene derivatives emerged as next-generation photocatalysts for hydrogen production in the last five years is provided. We also highlight how the size-modulation and functionalization of nano-carbon-based materials with active species can lead to improved photocatalytic performance. Furthermore, the potential of carbon dots and graphene-derivatives as noble metal-free co-catalysts and solid electron mediators in hydrogen evolution reaction under visible light illumination is discussed. The review finally elaborates the research gap and future perspectives, paving the way for new research to develop efficient photocatalysts for hydrogen production.