Tuning the ratio of Bi/Bi_(2)O_(3)in Bi/PNC nanosheet for highefficiency electrosynthesis hydrogen peroxide

Electrocatalytic two-electron oxygen reduction reaction(2e-ORR)is a promising method for producing green and sustainable H_(2)O_(2)but lacks high selectivity and yields electrocatalysts.And it is critical to develop catalysts that meet industrial demands.Herein,we report the different ratios of Bi0/Bi^(3+)supported on a phosphorus,nitrogen,and carbon nanosheet(Bi/PNC),which can reduce O_(2) to H_(2)O_(2)with high selectivity(up to 97.75%at 0.4 VRHE)in 0.1 M KOH electrolyte and retain 97%selectivity even after 100 h electrolysis.Then a homemade flow-cell system was built for electrocatalytic production of H_(2)O_(2)under an O_(2) atmosphere using an improved gas diffusion electrode.The Bi/PNC-4 can achieve a high H_(2)O_(2)yield of 2.76 mol·gcatalyst^(-1)·h^(-1)(alkaline),5.29 mol·gcatalyst^(-1)·h^(-1)(neutral),and 3.50 mol·gcatalyst^(-1)·h^(-1)(acid)in universal pH conditions.The in-situ generated H_(2)O_(2)can function as a degradation agent for efficiently degrading pesticides and antibiotics.The outstanding selectivity and activities are attributed to the synergistic effects of Bi0 and Bi^(3+)that promote proton-coupled reduction of O_(2) to OOH^(*)(ΔGOOH^(*)=4.27 eV),and the formation of H_(2)O_(2).The fast yield of H_(2)O_(2)on Bi/PNC catalysts in flow-cell provides a promising path of electrocatalytic 2e-ORR for practical H_(2)O_(2)production.