Yousaf Sheraz, Zulfiqar Sonia, Somaily H H, Warsi Muhammad Farooq, Rasheed Aamir, Shahid Muhammad, Ahmad Iqbal
Institute of Chemistry, The Islamia University of Bahawalpur Baghdad-ul-Jadeed Campus Bahawalpur-63100 Pakistan
Department of Chemistry, School of Sciences & Engineering, The American University in Cairo New Cairo 11835 Egypt.
RSC Adv. 2022 Aug 18;12(36):23454-23465. doi: 10.1039/d2ra03873k. eCollection 2022 Aug 16.
The design of oxygen evolution reaction (OER) catalysts with higher stability and activity by economical and convenient methods is considered particularly important for the energy conversion technology. Herein, a simple hydrothermal method was adopted for the synthesis of iodine-doped nickel hydroxide nanoparticles and their OER performance was explored. The electrocatalysts were structurally characterized by powder X-ray diffraction analysis (P-XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), and BET analysis. The electrochemical performance of the electrocatalysts was assessed by cyclic voltammetry, linear sweep voltammetry, and electrochemical impedance spectroscopy. The abundant catalytic active sites, oxygen vacancies, low charge-transfer resistance, and a high pore diameter to pore size ratio of iodine-doped Ni(OH) were responsible for its excellent catalytic activity, whereby OER was initiated even at 1.52 V ( RHE) and a 330 mV overpotential was needed to reach a 40 mV cm current density in 1 M KOH solution. The material also exhibited a low Tafel slope (46 mV dec), which suggests faster charge-transfer kinetics as compared to its counterparts tested under the same electrochemical environment. It is worth noting that this facile and effective approach suggests a new way for the fabrication of metal hydroxides rich in oxygen vacancies, thus with the potential to boost the electrochemical performance of energy-related systems.
通过经济便捷的方法设计具有更高稳定性和活性的析氧反应（OER）催化剂对于能量转换技术尤为重要。在此，采用一种简单的水热法合成了碘掺杂的氢氧化镍纳米颗粒，并探究了其析氧反应性能。通过粉末X射线衍射分析（P-XRD）、傅里叶变换红外光谱（FTIR）、场发射扫描电子显微镜（FESEM）、能量色散X射线光谱（EDX）和BET分析对电催化剂进行了结构表征。通过循环伏安法、线性扫描伏安法和电化学阻抗谱评估了电催化剂的电化学性能。碘掺杂的Ni(OH)丰富的催化活性位点、氧空位、低电荷转移电阻以及高孔径与孔径比是其优异催化活性的原因，由此在1 M KOH溶液中，即使在1.52 V（相对于可逆氢电极）时也能引发析氧反应，达到40 mV cm的电流密度需要330 mV的过电位。该材料还表现出低塔菲尔斜率（46 mV dec），这表明与其在相同电化学环境下测试的同类材料相比，电荷转移动力学更快。值得注意的是，这种简便有效的方法为制备富含氧空位的金属氢氧化物提供了一种新途径，因此有可能提高与能量相关系统的电化学性能。
