Biomass-derived hydrothermal carbonization carbon for photocatalytic H2O2 synthesis: Advances, opportunities and challenges

Hydrogen peroxide (H 2 O 2 ) is a cornerstone green oxidant and high-energy-density energy carrier, yet its predominant industrial production via the anthraquinone process is energy-intensive and environmentally detrimental. Solar-driven photocatalysis represents a sustainable alternative, but its practical application is hindered by catalysts that are often costly and unstable. Hydrothermal carbonization carbon (HTCC), derived from abundant biomass, have recently emerged as a cost-effective and eco-friendly catalyst platform. Despite rapid progress, the field still lacks a systematic review dedicated to the design principles, performance modulation, and future trajectory of HTCC for photocatalytic H 2 O 2 synthesis. This review first elucidates the fundamental mechanisms of photocatalytic H 2 O 2 generation. Subsequently, the advancements in HTCC for photocatalytic H 2 O 2 production are comprehensively reviewed. Furthermore, a focus on functionalization strategies of HTCC, including surface chemistry modification, morphological engineering, heterojunction construction, and post-calcination treatment are provided. Concluding with a critical analysis of current challenges, this review offers insightful perspectives to guide the rational design of next-generation HTCC photocatalysts for sustainable H 2 O 2 production.