Natural bamboo-derived O-doped rocky electrocatalyst for high-efficiency electrochemical reduction of O2 to H2O2

Abstract

The in-situ H2O2 electrosynthesis by two-electron oxygen reduction reaction employing renewable electricity is a promising alternative to traditional anthraquinone process due to its security, environmental friendliness and excellent cost effectiveness, which requires high-performance, cost-effective and environmental-friendly electrocatalysts. A bamboo-derived O-doped rocky electrocatalyst is developed by facile pyrolysis and acid treatment for high-efficiency electroreduction of O2 to H2O2. Three-dimensional interconnected hierarchical pores in rocky electrocatalysts expose abundant electroactive sites and facilitate mass transfer of reaction species. From the results of rotating ring-disk electrode test, a H2O2 selectivity up to 80% and superior electrocatalytic activity of the prepared electrocatalyst are achieved by surface oxygen functionalization induced by acid treatment. At the optimal catalyst loading of 2 mg cm−2, prominent H2O2 productivity of 1037 mmol gcatalyst−1h−1 with high current efficiency up to 74.1% is achieved at 30 mA cm−2 by air-breathing cathode. Higher H2O2 productivity (1525 mmol gcatalyst−1h−1) is yielded by further raising the current density to 50 mA cm−2. Moreover, the durability test of the cathode through ten consecutive runs demonstrates its great stability for electrocatalytic generation of H2O2. This work inspires the development of promising biomass-derived electrocatalysts for green and sustainable on-site H2O2 electrosynthesis.