Engineered Framework Photocatalysts for Green H 2 O 2 Synthesis: Overcoming Fundamental Barriers With MOFs, COFs, and HOFs

ABSTRACT Hydrogen peroxide (H 2 O 2 ) is an important green oxidant used in chemical synthesis and environmental remediation. However, its conventional anthraquinone‐based production is energy‐intensive, centralized, and environmentally demanding. Solar‐driven photocatalytic H 2 O 2 synthesis through selective oxygen reduction and water oxidation has emerged as a sustainable alternative, although practical implementation remains hindered by rapid charge recombination, limited oxygen activation, sluggish mass transfer, and catalyst‐induced H 2 O 2 decomposition. In this context, porous framework materials including metal–organic frameworks (MOFs), covalent organic frameworks (COFs), and hydrogen‐bonded organic frameworks (HOFs) have attracted significant attention due to their tunable porosity, programmable active sites, and versatile electronic structures. This review provides a unified and mechanistically informed analysis of framework‐based photocatalysts for H 2 O 2 production, correlating framework architecture, defect engineering, heterojunction formation, and active‐site coordination with photocatalytic performance. Key challenges associated with light harvesting, charge separation, oxygen transport, product stability, and long‐term durability are critically discussed alongside important benchmarking metrics such as apparent quantum yield and solar‐to‐chemical conversion efficiency. Furthermore, the review highlights scalability considerations and emerging design strategies required to transition framework‐based photocatalysts from laboratory studies toward decentralized and industrially relevant H 2 O 2 production systems. This work provides a comprehensive roadmap for the rational development of next‐generation porous photocatalysts for a sustainable economy.