The assessment of graphitic carbon nitride (g-C3N4) materials for hydrogen evolution reaction: Effect of metallic and non-metallic modifications

Photocatalytic hydrogen evolution is a viable and eco-friendly technology to deal with the energy crisis. Among diverse metallic and non-metallic photocatalysts, graphitic carbon nitride (g-C3N4) is recognized to have the great potential for the hydrogen evolution reaction (HER) with the aid of its widespread availability, low cost, and unique optical/electrical properties. This review discusses the advantageous photocatalytic properties of g-C3N4 for the generation of hydrogen. The mechanism and role of g-C3N4-based materials in the photocatalytic HER are also described along with their synthesis procedures and modification approaches with metallic and/or non-metallic components. The applicability of g-C3N4-based materials is assessed further based on figure of merit (FoM). Accordingly, the most effective strategies for g-C3N4-based HER are identified to include such options as the dye conjugation (e.g., C4BTP-C3N4, FoM = 1.35 × 10−4 mol g−1 Wh−1) and metallic-co-catalyst doping of g-C3N4 (e.g., Au-g-C3N4, FoM = 1.69 × 10−4 mol g−1 Wh−1).