Carbon-based materials for photo- and electrocatalytic synthesis of hydrogen peroxide

A high demand of hydrogen peroxide (H2O2) has been dominantly supplied by anthraquinone process for various applications globally in chemical synthesis, wastewater treatment and more; however, it is challenged regarding the centralized manufacturing and intensive energy input and waste output. The on-site production of H2O2 via electro- and photocatalytic water oxidation and oxygen reduction partially, which is greener and easier to handle, has emerged recently with extensive research aiming to seek active, selective and stable catalysts. Here, we review the current status and future perspectives in this field focused on carbon-based catalysts and their hybrids, since they are relatively low-cost, bio-friendly and flexible in structure modulation. We present state-of-the-art progresses, different classic catalyst engineering towards selective and active H2O2 production, electro- and photochemical mechanism discussion and H2O2 formation through both reductive and oxidative reaction pathways, ending with the key challenges to be overcome. We expect promising developments will be inspired in the near future towards practical decentralized H2O2 production and direct use.