Rajendiran Rajmohan, Chinnadurai Deviprasath, Chen Kai, Selvaraj Aravindha Raja, Prabakar Kandasamy, Li Oi Lun
Department of Materials Science and Engineering, Pusan National University, 2 Busandaehak-ro 63beon-gil, Geumjeong-gu, Busan, 46241, Republic of Korea.
Materials Technology Institute, Pusan National University, 2 Busandaehak-ro 63beon-gil, Geumjeong-gu, Busan, 46241, Republic of Korea.
ChemSusChem. 2021 Mar 5;14(5):1324-1335. doi: 10.1002/cssc.202002544. Epub 2021 Jan 21.
Tungsten-doped Ni-Fe hydroxides fabricated on a three-dimensional nickel foam through cathodic electrodeposition are proposed as effective oxygen evolution reaction (OER) catalysts for alkaline water oxidation. Incorporating an adequate amount of W into Ni-Fe hydroxides modulates the electronic structure by changing the local environment of Ni and Fe and create oxygen vacancies, resulting in abundant active sites for the OER. The optimized electrocatalyst, with a substantial number of catalytic sites, is found to outperform the well-established 20 wt% Ir/C electrocatalyst. The catalyst only requires small overpotentials of 224 mV and 251 mV to generate current densities of 10 mA cm and 50 mA cm , respectively, at an extremely low Tafel slope. Surface study after long-term chronopotentiometry (ca. 30 h) reveals that the tungsten dopant undergoes reduction to stabilize the Ni and Fe active sites for predominant water oxidation. This research provides new insight to apply optimum amounts of tungsten doping to enable more significant electronic coupling within Ni-Fe for the chemisorption of hydroxy and oxygen intermediates and greatly improved OER activity.
通过阴极电沉积在三维泡沫镍上制备的钨掺杂镍铁氢氧化物被提议作为碱性水氧化中有效的析氧反应（OER）催化剂。在镍铁氢氧化物中掺入适量的钨，通过改变镍和铁的局部环境来调节电子结构并产生氧空位，从而为析氧反应提供丰富的活性位点。优化后的电催化剂具有大量催化位点，其性能优于成熟的20 wt% Ir/C电催化剂。该催化剂在极低的塔菲尔斜率下，分别仅需224 mV和251 mV的小过电位就能产生10 mA cm 和50 mA cm 的电流密度。长期计时电位法（约30 h）后的表面研究表明，钨掺杂剂发生还原反应以稳定镍和铁活性位点，从而实现主要的水氧化反应。本研究为应用适量的钨掺杂提供了新的见解，以在镍铁中实现更显著的电子耦合，促进羟基和氧中间体的化学吸附，并大大提高析氧反应活性。
