Developing transition metal oxides(TMOs)as electrocatalysts with high bifunctional activity is of significance for reversible fuel cells and rechargeable metal air batteries.Herein,we report a bifunctional nitrogen-do...Developing transition metal oxides(TMOs)as electrocatalysts with high bifunctional activity is of significance for reversible fuel cells and rechargeable metal air batteries.Herein,we report a bifunctional nitrogen-doped NiCoO_(x)nanosheet array,which can stably catalyze the oxygen evolution reaction(OER)and the oxygen reduction reaction(ORR).The nanosheet has an ultrathin thickness of 1-3 nm and mesoporous structure,which are favorable for the exposure of active sites.Moreover,the nanosheet has pronounced crystalline distortions as revealed by means of X-ray absorption fine structure analysis.The distortions yield an abundance of catalytically active defects(e.g.oxygen vacancies),thereby giving rise to enhanced electrocatalytic performance.The nanosheet array exhibits an ultra-small overpotential of only 239 mV at 10 mA cm^(-2)for the OER and a low overpotential of 382 mV at 10 mA cm^(-2)for the ORR,which places it as being one of the most active bifunctional oxygen electrocatalysts.The assembled Zn-air battery shows excellent cycling stability over 200 h during consecutive charge(OER)and discharge(ORR)processes.展开更多
基金financial support from the National Natural Science Foundation of China(no.52272289,21972163)the Fundamental Research Funds for the Central Universities,the DHU Distinguished Young Professor Program,the Development Fund for Shanghai Talents,the Foundation of State Key Laboratory of Coal Conversion(grant no.J21-22-903)+3 种基金the Innovation Program of Shanghai Municipal Education Commission(program no.2021-01-07-00-03-E00109)the Eastern Scholar Research Fund Shanghai Institutions of Higher Learningfinancial support from the Shanghai Pujiang Program(21PJ1400400)the Research Start-up Fund at DHU.EXAFS results were obtained at the BL14W1 beamline in the Shanghai Synchrotron Radiation Facility(2019-SSRF-PT-010451).
文摘Developing transition metal oxides(TMOs)as electrocatalysts with high bifunctional activity is of significance for reversible fuel cells and rechargeable metal air batteries.Herein,we report a bifunctional nitrogen-doped NiCoO_(x)nanosheet array,which can stably catalyze the oxygen evolution reaction(OER)and the oxygen reduction reaction(ORR).The nanosheet has an ultrathin thickness of 1-3 nm and mesoporous structure,which are favorable for the exposure of active sites.Moreover,the nanosheet has pronounced crystalline distortions as revealed by means of X-ray absorption fine structure analysis.The distortions yield an abundance of catalytically active defects(e.g.oxygen vacancies),thereby giving rise to enhanced electrocatalytic performance.The nanosheet array exhibits an ultra-small overpotential of only 239 mV at 10 mA cm^(-2)for the OER and a low overpotential of 382 mV at 10 mA cm^(-2)for the ORR,which places it as being one of the most active bifunctional oxygen electrocatalysts.The assembled Zn-air battery shows excellent cycling stability over 200 h during consecutive charge(OER)and discharge(ORR)processes.
