Dang Yanliu, He Junkai, Wu Tianli, Yu Linping, Kerns Peter, Wen Liaoyong, Ouyang Jing, Suib Steven L
Henan Key Laboratory of Photovoltaic Materials and School of Physics & Electronics , Henan University , Kaifeng 475004 , P. R. China.
ACS Appl Mater Interfaces. 2019 Aug 21;11(33):29879-29887. doi: 10.1021/acsami.9b08238. Epub 2019 Aug 6.
Pursuing cost-effective water-splitting catalysts is still a significant scientific challenge to produce renewable fuels and chemicals from various renewable feedstocks. The construction of controllable binder-free nanostructures with self-standing holey and ultrathin nanosheets is one of the promising approaches. Herein, by employing a combination of the potentiodynamic mode of electrodeposition and low-temperature phosphidation, three-dimensional (3D) holey CoP ultrathin nanosheets are fabricated on a carbon cloth (PD-CoP UNSs/CC) as bifunctional catalysts. Electrochemical tests show that the PD-CoP UNSs/CC exhibits outstanding hydrogen evolution reaction performance at all pH values with overpotentials of 47, 90, and 51 mV to approach 10 mA cm in acidic, neutral, and alkaline media, respectively. Meanwhile, only a low overpotential of 268 mV is required to drive 20 mA cm for the oxygen evolution reaction in alkaline media. Cyclic voltammetry and impedance studies suggest the enhanced performance is mainly attributed to the unique 3D holey ultrathin nanosheets, which could increase the electrochemically active area, facilitate the release of gas bubbles from electrode surfaces, and improve effective electrolyte diffusion. This work suggests an efficient path to design and fabricate non-noble bifunctional electrocatalysts for water splitting at a large scale.
寻求具有成本效益的析氢催化剂仍然是一项重大的科学挑战，其目的是从各种可再生原料中生产可再生燃料和化学品。构建具有自支撑多孔和超薄纳米片的可控无粘结剂纳米结构是一种很有前景的方法。在此，通过结合电沉积的动电位模式和低温磷化，在碳布上制备了三维（3D）多孔CoP超薄纳米片（PD-CoP UNSs/CC）作为双功能催化剂。电化学测试表明，PD-CoP UNSs/CC在所有pH值下均表现出出色的析氢反应性能，在酸性、中性和碱性介质中，过电位分别为47、90和51 mV时，电流密度接近10 mA cm。同时，在碱性介质中，驱动析氧反应达到20 mA cm时，仅需268 mV的低过电位。循环伏安法和阻抗研究表明，性能的提高主要归因于独特的3D多孔超薄纳米片，它可以增加电化学活性面积，促进气泡从电极表面释放，并改善有效电解质扩散。这项工作为大规模设计和制造用于析氢的非贵金属双功能电催化剂提供了一条有效途径。
