Engineering oxygen vacancies of cobalt tungstate nanoparticles enable efficient water splitting in alkaline medium
Engineering oxygen vacancies of cobalt tungstate nanoparticles enable efficient water splitting in alkaline medium
复制标题
钨酸钴纳米粒子的工程氧空位能够在碱性介质中有效分解水
DOI：
10.1016/j.apcatb.2019.118090
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Cai Weiwei
中科院分区：
文献类型：
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作者：
Luo Fang;Xu Ruizhi;Ma Shuangxiu;Zhang Quan;Hu Hao;Qu Kongang;Xiao Shenglin;Yang Zehui;Cai Weiwei
开发地球丰富、高效、稳定的水分解电催化剂对于环境友好的能源转换和储存至关重要。在这里，我们报道了一种直径为 8 nm 的缺氧钨酸钴纳米颗粒（CoWO4-x@C）作为析氢反应（HER）和氧还原反应（OER）的高效双功能电催化剂，其表现出与商用 Pt/C 相当的 HER 活性，相对于 RHE 的过电势分别为 32.5 mV 和 46.8 mV，在酸性和碱性介质中分别提供 10 mA cm−2 的电流密度，归因于丰富的氧空位分别促进氢吸附及其相对重组。此外，在 10,000 次潜在循环后，CoWO4-x@C 观察到不可检测的降解，表明其具有高耐久性。同时，CoWO4-x@C在OER测试中仅需要295 mV的过电势即可提供10 mA cm−2，这优于基准IrO2（313 mV）。要实现 10 mA cm−2 的水分解电流密度且 12 小时内没有任何降解，需要 1.57 V 的电压，该电压相对低于 Pt/C-IrO2 (1.59 V)。
Development of earth-abundant, efficient and stable electrocatalysts for water splitting is of crucial importance for environmentally friendly energy conversion and storage. Here, we report an oxygen deficient cobalt tungstate nanoparticles with diameter of 8 nm (CoWO4-x@C) as efficient bifunctional electrocatalyst for hydrogen evolution reaction (HER) and oxygen reduction reaction (OER), which exhibits comparable HER activity to commercial Pt/C with overpotentials of 32.5 mV and 46.8 mV vs. RHE to deliver current density of 10 mA cm−2in acidic and alkaline mediums, respectively, ascribed to the rich oxygen vacancies facilitating the hydrogen adsorption and its relative recombination, respectively. Additionally, undetectable degradation is observed for CoWO4-x@C after 10,000 potential cycles indicating high durability. Meanwhile, CoWO4-x@C requires only 295 mV overpotential to deliver 10 mA cm−2in the OER test, which is better than the benchmarking IrO2(313 mV). 1.57 V comparably lower than Pt/C-IrO2(1.59 V) is required for achieving the water splitting current density of 10 mA cm−2without any degradation for 12 h.