Co3+-O-V4+ cluster in CoVOx nanorods for efficient and stable electrochemical oxygen evolution
Co3+-O-V4+ cluster in CoVOx nanorods for efficient and stable electrochemical oxygen evolution
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DOI：
10.1016/j.apcatb.2020.119571
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发表时间：
2021-03
期刊：
影响因子：
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通讯作者：
Chaoran Jiang;Ji Yang;Tingting Zhao;Lunqiao Xiong;Zhengxiao Guo;Yujing Ren;Haifeng Qi;Aiqin Wang;Junwang Tang
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文献类型：
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作者：
Chaoran Jiang;Ji Yang;Tingting Zhao;Lunqiao Xiong;Zhengxiao Guo;Yujing Ren;Haifeng Qi;Aiqin Wang;Junwang Tang
开发具有成本效益和长期稳定的析氧反应（OER）催化剂对于从水中生产清洁和可持续的H2燃料至关重要。在这里，我们展示了钴钒氧化物（CoVOx-300）作为这样一种有效和耐用的电催化剂。这样的活性催化剂是有益的，从平衡的Co 3 +-O-V 4+活性物种，其显示出高的表面Co 3+含量与匹配的V 4+产生的快速热处理。CoVOx-300具有最高的Co 3 +/Co2+比1.4和相应的最高的V4+/ V5+比1.7，表现出显著的OER活性，在10 mA cm−2（η10）的电流密度下，过电位为330 mV，在0.38 VvsRHE的过电位下，仅为46 mV dec-1的浅Tafel斜率和100 mA cm− 2的电流密度，其比活性CoOx-300高20倍，比VOx-300高1000倍。该催化剂还显示出在碱性介质中10 h的优异稳定性和相对于CoOx-300降低40%的活化能。CoVOx-300的过电位（η10）也分别比相应的CoOx-300和CoVOx催化剂低近70和80 mV，并且比商业基准催化剂RuO 2的塔菲尔斜率低20%。因此，本研究首次证明了表面Co 3 +-O-V4+物种在改善水氧化反应的电催化性能和稳定性方面起着至关重要的作用，并且该方法允许合理设计和合成其他活性过渡金属氧化物以实现有效的OER活性。
The development of cost-efficient and long-term stable catalysts for the oxygen evolution reaction (OER) is crucial to produce clean and sustainable H2fuels from water. Here we demonstrate a cobalt vanadium oxide (CoVOx-300) working as such an efficient and durable electrocatalyst. Such an active catalyst is beneficial from the balanced Co3+-O-V4+active species, which show the high surface Co3+contents with matched V4+generated by rapid heat treatment. The CoVOx-300 with highest Co3+/Co2+ratio of 1.4 and corresponding highest V4+/ V5+ratio of 1.7 exhibits remarkable OER activity with an overpotential of 330 mV at current density of 10 mA cm−2(η10), a shallow Tafel slope of only 46 mV dec-1and a current density of 100 mA cm−2at an overpotential of 0.38 VvsRHE, which is 20 times higher than the active CoOx-300 and 1000 times higher than VOx-300. The catalyst also shows excellent stability for 10 h in alkaline media and a 40 % reduced activation energy to the counterpart, CoOx-300. The overpotential (η10) of CoVOx-300 also shows nearly 70 and 80 mV lower than the corresponding CoOx-300 and CoVOx catalysts, respectively and 20 % lower Tafel slope than the commercial benchmark catalyst RuO2. Thus, this study for the first time demonstrates that surface Co3+-O-V4+species play a crucial role in improving electrocatalytic properties and stability for water oxidation reaction and the approaches allow the rational design and synthesis of other active transition metal oxides toward efficient OER activity.