Anion exchange membrane electrolysis (AEMWE) is currently a promising technology to produce hydrogen from water. Developing the highly intrinsic activity of electrodes is extremely important. In this paper, nitrogen v...Anion exchange membrane electrolysis (AEMWE) is currently a promising technology to produce hydrogen from water. Developing the highly intrinsic activity of electrodes is extremely important. In this paper, nitrogen vacancies-rich cobalt nitride (Co_(4)N-VN) is used as the anode catalyst of the urea oxidation reaction (UOR) and its loading Pt (Pt@Co_(4)N-VN) acted as the cathode of hydrogen evolution reaction (HER). The introduction of N-vacancies gained the electron-deficient Co_(4)N more favorable for the UOR process. Meanwhile, the electron transfer between the Co_(4)N-VN carrier and Pt can enhance the intrinsic HER activity of loaded Pt. Specifically, in the 0.33 M urea and 1.0 M KOH electrolyte, the UOR potential of CO_(4)N-VN is only 1.58 V at the current density of 300.0 mA cm^(-2), which is much lower than that of Co_(4) N and Co_(3)O_(4). At the same time, the HER overpotential at 1.0 M KOH and 300.0 mA cm^(-2) is only 120.0 mV, lower than 20 wt% Pt/C. By measuring the bode phase diagram, the presence of N-vacancies can accelerate the electron transfer rate of catalysts to improve the UOR and HER electrocatalytic activity. The overall water-splitting device featuring Pt@Co_(4)N-VN||Co_(4)N-VN electrodes achieves a voltage of 2.99 V at a current density of 300.0 mA cm^(-2).展开更多
基金supported by the National Natural Science Foundation of China(Nos.52302272 and 52377026)the Taishan Scholars Program(Nos.tsqn202211124 and tsqn202103057)+4 种基金the Natural Science Foundation of Shandong Province(Nos.ZR2022QB023 and ZR2024ME046)the Qingchuang Talents Induction Program of Shandong Higher Education Insti-tution(Research and Innovation Team of Marine Polysaccharides Fibers-based Energy Materials)the Key Innovative Research Team of New Energy Materials and Devices(No.BBXYKYTDxjZD01)the University Natural Science Research Project of Anhui Province(No.2022AH010101)the State Key Laboratory of Bio-Fibers and Eco-Textiles,Qingdao University(Nos.ZKT10 and GZRC202006).
文摘Anion exchange membrane electrolysis (AEMWE) is currently a promising technology to produce hydrogen from water. Developing the highly intrinsic activity of electrodes is extremely important. In this paper, nitrogen vacancies-rich cobalt nitride (Co_(4)N-VN) is used as the anode catalyst of the urea oxidation reaction (UOR) and its loading Pt (Pt@Co_(4)N-VN) acted as the cathode of hydrogen evolution reaction (HER). The introduction of N-vacancies gained the electron-deficient Co_(4)N more favorable for the UOR process. Meanwhile, the electron transfer between the Co_(4)N-VN carrier and Pt can enhance the intrinsic HER activity of loaded Pt. Specifically, in the 0.33 M urea and 1.0 M KOH electrolyte, the UOR potential of CO_(4)N-VN is only 1.58 V at the current density of 300.0 mA cm^(-2), which is much lower than that of Co_(4) N and Co_(3)O_(4). At the same time, the HER overpotential at 1.0 M KOH and 300.0 mA cm^(-2) is only 120.0 mV, lower than 20 wt% Pt/C. By measuring the bode phase diagram, the presence of N-vacancies can accelerate the electron transfer rate of catalysts to improve the UOR and HER electrocatalytic activity. The overall water-splitting device featuring Pt@Co_(4)N-VN||Co_(4)N-VN electrodes achieves a voltage of 2.99 V at a current density of 300.0 mA cm^(-2).
