Simultaneously modulating morphology and electronic structure of carbon-fiber: A strategy for constructing efficient electrocatalyst to on-site produce H2O2 in wide pH

Abstract

On-site production of H 2 O 2 via a two-electron oxygen reduction reaction (2e -ORR) presents a sustainable alternative to the energy-intensive anthraquinone process. However, the development of efficient and stable electrocatalysts in wide pH remains a critical challenge. Herein, fluorine-doped porous carbon fiber (F-CF) were synthesized by simply annealing the electrospun of polytetrafluoroethylene (PTFE) and polyvinylpyrrolidone (PVP). The obtained F-CF has a hierarchical macro/meso/micro-pores structure due to the decomposition of PTFE, and exhibits excellent 2e -ORR catalytic activity and durability for H 2 O 2 production in wide pH (3~14). In alkaline media, a remarkable H 2 O 2 yields of 7.30 mol h -1 g cat. -1 (0.3 V vs. RHE) with a Faraday efficiency (FE) over 90% can be obtained. Notably, the F-CF maintains outstanding performance and stability under neutral and even acidic conditions. Density functional theory (DFT) calculations reveal that the F-doping regulates the electronic structure of CF, which can enhance its ability for O 2 adsorption and thus improve the catalytic performance for H 2 O 2 production. The practicability of F-CF was further certified by the on-site produced H 2 O 2 at different pH: bleaching (alkaline), disinfection (neutral), and dye degradation (acidic). This work opens up a new way to design efficient carbon-based 2e -ORR electrocatalysts by the morphology and electronic structure engineering, broadening the prospects of decentralized H 2 O 2 production in many fields.