Nejati Kamellia, Jafari Foruzin Leila, Rezvani Zolfaghar
Department of Chemistry, Payame Noor University, P.O. Box 19395-3697, Tehran, Iran.
Department of Chemistry, Faculty of Basic Sciences, Azarbaijan Shahid Madani University, Tabriz, Iran.
Dalton Trans. 2021 Jun 1;50(21):7223-7228. doi: 10.1039/d1dt01144h.
Herein, we describe a simple microwave method for the doping of Cu2+ into NiCr-LDH and the preparation of ternary Ni2.25Cu0.75Cr-LDH as a superior electrocatalyst for water oxidation in a neutral solution. The obtained Ni2.25Cu0.75Cr-LDH was characterized by XRD, DRS, TEM and FE-SEM techniques. The results showed that Ni2.25Cu0.75Cr-LDH was formed with a size of 30 nm. In order to examine the water oxidation activity of Ni2.25Cu0.75Cr-LDH, the as-prepared samples were used as an electrocatalyst-modified carbon paste electrode in neutral solution. The electrochemical results revealed that the optimized Ni2.25Cu0.75Cr-LDH presented extraordinary water oxidation activity with a low onset potential of 1.40 V (vs. RHE) and an overpotential of 170 mV compared to other molar ratios (Ni2.5Cu0. 5Cr-LDH), (Ni2CuCr-LDH), and bimetallic (CuCr-LDH), and even outperformed NiCr-LDH. Also, a small Tafel slope of 31 mV and high durability of 14 h could be obtained for Ni2.25Cu0.75Cr-LDH. The excellent OER could be assigned to the decreased band gap energy and increased charge transfer at Ni2.25Cu0.75Cr-LDH. Therefore, Ni2.25Cu0.75Cr-LDH is a promising water oxidation catalyst owing to its improved charge transfer ability.
在此，我们描述了一种将Cu2+掺杂到NiCr-LDH中的简单微波方法，以及制备三元Ni2.25Cu0.75Cr-LDH作为中性溶液中用于水氧化的优异电催化剂的方法。通过XRD、DRS、TEM和FE-SEM技术对所制备的Ni2.25Cu0.75Cr-LDH进行了表征。结果表明，形成了尺寸为30nm的Ni2.25Cu0.75Cr-LDH。为了研究Ni2.25Cu0.75Cr-LDH的水氧化活性，将所制备的样品用作中性溶液中电催化剂修饰的碳糊电极。电化学结果表明，优化后的Ni2.25Cu0.75Cr-LDH具有非凡的水氧化活性，起始电位低至1.40V（相对于RHE），与其他摩尔比（Ni2.5Cu0.5Cr-LDH）、（Ni2CuCr-LDH）和双金属（CuCr-LDH）相比，过电位为170mV，甚至优于NiCr-LDH。此外，Ni2.25Cu0.75Cr-LDH的塔菲尔斜率小至31mV，耐久性高达14h。优异的析氧反应可归因于Ni2.25Cu0.75Cr-LDH的带隙能量降低和电荷转移增加。因此，Ni2.25Cu0.75Cr-LDH由于其改善的电荷转移能力而成为一种有前途的水氧化催化剂。
