Peng Xingcui, Nie Xuezhong, Zhang Lei, Liang Taiping, Liu Yi, Liu Peng, Men Yu-Long, Niu Lin, Zhou Jian, Cui Daxiang, Pan Yun-Xiang
Institute of Nano Biomedicine and Engineering, Shanghai Engineering Research Centre for Intelligent Diagnosis and Treatment Instrument, Department of Instrument Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China.
State Key Laboratory of Catalysis, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, P. R. China.
ACS Appl Mater Interfaces. 2020 Dec 23;12(51):56943-56953. doi: 10.1021/acsami.0c13547. Epub 2020 Dec 13.
Electrocatalytic oxidation of water (, oxygen evolution reaction, OER) plays crucial roles in energy, environment, and biomedicine. It is a key factor affecting the efficiencies of electrocatalytic reactions conducted in aqueous solution, , electrocatalytic water splitting and glucose oxidation reaction (GOR). However, electrocatalytic OER still suffers from problems like high overpotential, sluggish kinetics, and over-reliance on expensive noble-metal-based catalysts. Herein, 15 nm thick carbon-based shell coated tungsten oxide (CTO) nanospheres are loaded on nickel foam to form CTO/NF. An enhanced electrocatalytic OER is triggered on CTO/NF, with the overpotential at 50 mA cm (317 mV) and the Tafel slope (70 mV dec) on CTO/NF lower than those on pure tungsten oxide (360 mV, 117 mV dec) and noble-metal-based IrO catalysts (328 mV, 96 mV dec). A promoted electrocatalytic GOR is also achieved on CTO/NF, with efficiency as high as 189 μA mM cm. The carbon-based shell on CTO is flexible for electron transfer between catalyst and reactants and provides catalytically active sites. This improves reactant adsorption and O-H bond dissociation on the catalyst, which are key steps in OER and GOR. The carbon-based shell on CTO retains the catalyst as nanospheres with a higher surface area, which facilitates OER and GOR. It is the multiple roles of the carbon-based shell that increases the electrocatalytic efficiency. These results are helpful for fabricating more efficient noble-metal-free electrocatalysts.
水的电催化氧化（即析氧反应，OER）在能源、环境和生物医学领域发挥着至关重要的作用。它是影响在水溶液中进行的电催化反应效率的关键因素，例如电催化水分解和葡萄糖氧化反应（GOR）。然而，电催化析氧反应仍然存在诸如高过电位、缓慢的动力学以及对昂贵的基于贵金属的催化剂过度依赖等问题。在此，将15纳米厚的碳基壳包覆氧化钨（CTO）纳米球负载在泡沫镍上形成CTO/NF。CTO/NF引发了增强的电催化析氧反应，在50 mA cm²时的过电位为317 mV，CTO/NF的塔菲尔斜率为70 mV dec⁻¹，低于纯氧化钨（360 mV，117 mV dec⁻¹）和基于贵金属的IrO₂催化剂（328 mV，96 mV dec⁻¹）。在CTO/NF上也实现了促进的电催化葡萄糖氧化反应，效率高达189 μA mM⁻¹ cm⁻²。CTO上的碳基壳对于催化剂与反应物之间的电子转移具有灵活性，并提供催化活性位点。这改善了反应物在催化剂上的吸附以及O - H键的解离，而这是析氧反应和葡萄糖氧化反应中的关键步骤。CTO上的碳基壳将催化剂保留为具有更高表面积的纳米球，这有利于析氧反应和葡萄糖氧化反应。正是碳基壳的多种作用提高了电催化效率。这些结果有助于制备更高效的无贵金属电催化剂。
