Oxidase-Inspired Selective 2e/4e Reduction of Oxygen on Electron-Deficient Cu | doi.page

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Oxidase-Inspired Selective 2e/4e Reduction of Oxygen on Electron-Deficient Cu

ACS Applied Materials & Interfaces2020Vol. 12(4), pp. 4833–4842

Citations Over TimeTop 11% of 2020 papers

Fei He, Yong‐Fei Zheng, Huailin Fan, Delong Ma, Qifeng Chen, Tao Wei, Weibing Wu, Dan Wu, Xun Hu

Abstract

Development of low-cost and efficient (electro)catalysts with tunable 2e/4e oxygen reduction reaction (ORR) selectivity toward energy conversion, biomimetic catalysis, and biosensing has attracted growing interest. Herein, we reported that carbon nanohybrids with O- or N-coordinated Cu (Cu-OC or Cu-NC) showed superior activity for 2e and 4e electrocatalytic ORR with selectivities of 84.0% and 97.2%, respectively. Experimental evidence demonstrated that the strong electron-rich O-doped carbon in Cu-OC donated electrons to Cu2+, weakening the binding strength of H₂O₂ at Cu-O centers and facilitating the 2e ORR pathway for selective production of H₂O₂. However, the poor electron-donor ability of the N-doped carbon in Cu-NC made Cu-N sites more electron deficient due to the reduced electron transfer from N-doped carbon to Cu2+, promoting 4e ORR by enhancing adsorption of O₂ and the ORR intermediates. The high 4e ORR activity of Cu-NC rendered its potential for application in a Zn-air battery and oxidase-mimicking activity for 3,3',5,5'-tetramethylbenzidine (TMB) and ascorbic acid (AA) oxidation. The maximal velocity (V_max) of TMB and AA oxidation over Cu-NC was higher than some natural oxidases and noble-metal-based artificial enzymes. The lower activation energy for AA oxidation over Cu-NC resulted in a 263-fold higher oxidative rate than TMB, further prompting nonenzymatic sensing of AA by the competitive oxidation strategy.

Citations Over TimeTop 11% of 2020 papers

Abstract

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