Graphitic carbon nitride (g-C3N4)-based metal-free photocatalysts for water splitting: A review

A variety of g-C3N4-based metal-free photocatalysts for H-2 generation including structurally manipulated g-C3N4, g-C3N4-doped with non-metallic elements and molecules, hetero-junctions of g-C3N4 with carbonaceous materials, polymers as well as SiC and g-C3N4-based iso-type or homo-junctions are considered. Innumerable strategies have been attempted to enhance H-2 evolution rate of g-C3N4-derived metal-free photocatalysts compared to pure g-C3N4. Furthermore, challenges in this area are yet to be tackled to resolve the issues low efficiency, low stability and dependence on noble metal co-catalysts for increasing the product yield and reduction in redox capability by narrowing the band gap. This review attempts to cover the latest developments, especially in the area of graphitic carbon nitride (g-C3N4)-based metal-free photocatalysts for H-2 generation. (C) 2019 Elsevier Ltd. All rights reserved.