A review on synthesis, modification method, and challenges of light-driven H2 evolution using g-C3N4-based photocatalyst

The energy scarcity is exacerbating and needs an urgent solution. The most plausible solution to address the forthcoming energy scarcity is to diversify the energy sources. Developing the water-splitting process (WSP) efficiency depends on solar energy representing "21st-century dream technology". We present a comprehensive review of related papers employing graphitic carbon nitride (g-C3N4) as pure, doped, or composite nanostructure in the evolution of hydrogen from water dissociation under simulated sunlight irradiation, mainly in the last ten years. Herein, after a concise introduction to the main principle of the water-splitting process, the methods to synthesize, modify and upgrade the photocatalytic performance of g-C3N4 were reviewed in detail. Moreover, the main challenges of using g-C3N4-based photocatalytic material in WSP have been mentioned. The report mainly targets the g-C3N4 character, synthesis method, photocatalytic activity, and strategies toward enhancing photoreactivity under visible light, along with the reusability of the fabricated nanohybrid catalysts. Above and over, this review suggests the potential of g-C3N4 to produce green H2 from water at a competitive price, which can contribute to satisfying the global energy sector demand and suppressing global warming.