Zeng Kai, Yu Haiyang, Sun Zhihui, Yan Jin, Zheng Xiangjun, Jiang Yongxiang, Hu Wanlu, Tian Jing-Hua, Yang Ruizhi
College of Energy, Soochow Institute for Energy and Materials Innovations, Soochow University, Suzhou 215006, China.
Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou 215006, China.
ACS Appl Mater Interfaces. 2020 Sep 2;12(35):39205-39214. doi: 10.1021/acsami.0c10678. Epub 2020 Aug 21.
Ni-Mn-based binary oxides are deemed as prospective electrocatalysts for water oxidation. Here, a murdochite-type NiMnO electrocatalyst for water oxidation is reported. Murdochite-type NiMnO with hollow sphere (NMO-HS) and microflower (NMO-MF) structures has been controllably synthesized. After an in-situ activation process, the NMO-MF affords a superior activity for oxygen evolution reaction in 0.1 M KOH. A low overpotential of 370 mV at 10 mA cm is obtained, and the mass activity of activated NMO-MF is 1.96 times that of commercial IrO/C. As revealed by in-situ Raman spectra, Ni species in activated NMO-MF act as intrinsic active sites, and the in-situ formed NiOOH on the surface during the activation process is identified to contribute to the significantly enhanced catalytic activity. The Zn-air battery assembled with a NMO-MF cathode showed an exceptional power density (0.228 W cm) and long-term cycling stability (148 h).
镍锰基二元氧化物被认为是用于水氧化的潜在电催化剂。在此，报道了一种用于水氧化的钙锰矿型镍锰氧化物电催化剂。已可控合成了具有空心球（NMO-HS）和微花（NMO-MF）结构的钙锰矿型镍锰氧化物。经过原位活化过程后，NMO-MF在0.1 M KOH中对析氧反应具有优异的活性。在10 mA cm时获得了370 mV的低过电位，活化后的NMO-MF的质量活性是商业IrO/C的1.96倍。原位拉曼光谱表明，活化后的NMO-MF中的镍物种作为本征活性位点，并且在活化过程中表面原位形成的NiOOH被确定有助于显著提高催化活性。用NMO-MF阴极组装的锌空气电池表现出优异的功率密度（0.228 W cm）和长期循环稳定性（148 h）。
