Advanced functional porous materials for photocatalytic H₂O₂ production

Hydrogen peroxide (H₂O₂) is one of the most essential chemicals; it has a high oxidising ability (1.763 V at pH 0) and the highest active oxygen content (47.1 wt%). Current synthesis techniques are energy-intensive, generate harmful waste, and pose the potential danger of explosions. Photocatalytic H₂O₂ production via O₂ reduction is a promising, sustainable, and eco-friendly method that harnesses solar energy to drive the reaction while also requiring low energy input and ensuring safety. Interestingly, advanced functional porous materials (AFPMs) like covalent organic frameworks (COFs), metal-organic frameworks (MOFs), porous organic polymers (POPs), covalent triazine frameworks (CTFs), metal-organic polyhedra (MOP) and hydrogen bonded organic frameworks (HOFs) have surfaced as promising photocatalysts for effective photocatalysis. These materials exhibit a tunable pore size, high surface area, and robust framework, all of which facilitate mass transfer, adequate active sites, and efficient recycling. In this review, we have discussed the different strategies applied in recent literature to improve the photocatalytic efficiency of these materials towards photocatalytic H₂O₂ synthesis. This review provides an extensive summary and discussion of the latest applications of AFPM-based photocatalysts in H₂O₂ photosynthesis. The historical background and fundamental principles underlying photocatalysts for photocatalytic H₂O production are briefly outlined. This is followed by a detailed classification and discussion of the strategies reported to enhance photocatalytic performance. The review addresses the challenges and future prospects of AFPM-based photocatalysts for light-driven H₂O₂ production.