Advanced Nanocarbons Toward two-Electron Oxygen Electrode Reactions for H 2 O 2 Production and Integrated Energy Conversion.

Hydrogen peroxide (H 2 O 2 ) plays a pivotal role in advancing sustainable technologies due to its eco-friendly oxidizing capability. The electrochemical two-electron (2e - ) oxygen reduction reaction and water oxidation reaction present an environmentally green method for H 2 O 2 production. Over the past three years, significant progress is made in the field of carbon-based metal-free electrochemical catalysts (C-MFECs) for low-cost and efficient production of H 2 O 2 (H 2 O 2 EP). This article offers a focused and comprehensive review of designing C-MFECs for H 2 O 2 EP, exploring the construction of dual-doping configurations, heteroatom-defect coupling sites, and strategic dopant positioning to enhance H 2 O 2 EP efficiency; innovative structural tuning that improves interfacial reactant concentration and promote the timely release of H 2 O 2 ; modulation of electrolyte and electrode interfaces to support the 2e - pathways; and the application of C-MFECs in reactors and integrated energy systems. Finally, the current challenges and future directions in this burgeoning field are discussed.