Harnessing mesoporous g-C ₃ N ₄ -based photocatalytic materials for sustainable fuel production via solar energy conversion: a review

The current energy production technology is associated with incompetent and unsustainable global conditions like climate change, the greenhouse effect, etc. Therefore, the call for sustainable and renewable energy practices is essential to address future energy crises, preserve ecological balance and combat climate change. Harnessing solar energy conversion via artificial photosynthesis over an efficient semiconductor is a key strategy to maintain the circular energy cycle and achieve zero-emission energy missions. g-C₃N₄ is one of the most exclusively studied semiconductor-photocatalysts; however, its bulk structure suffers from several significant limitations. Rational modifications of morphology and porosity led to the development of a mesoporous-C₃N₄ (mp-g-CN) framework, which has excellent photoresponsive features. mp-g-CN enriched with superior physicochemical properties, improved optoelectronic features, and well-dispersed active site distribution can be synthesized by either template-assisted or template-free synthesis methods. The template-free synthesis approach is more appealing than the template-assisted synthesis method, which can reduce the multiple synthesis steps and avoid the use of hazardous chemicals. Further, the strategic functional modifications deliver more efficient mp-g-CN structures, which can be considered as a reference photoactive material for producing H₂, H₂O₂, NH₃, carbonated fuel and biofuels from renewable precursors. Finally, some unresolved hitches in advancing mp-g-CN photocatalysts to achieve high efficiency in artificial photosynthesis have been encountered as current challenges and future prospects.