A simple template‐free hydrothermal route followed by high temperature (800 °C) annealing in air forms Ni‐Mn bimetallic oxides, namely NiMn 2 O 4 , Ni 1.5 Mn 1.5 O 4, MnNi 2 O 4 and are characterized by XRD, Raman, EDS, and SEM analysis. Electrocatalytic activity of these metal oxides toward the oxidation of glycine molecules in alkaline condition was studied by cyclic voltammetry and linear sweep voltammetry methods. Among other nickel manganese bimetallic oxides and monometallic oxides (Mn 2 O 3 , NiO), Ni 1.5 Mn 1.5 O 4 shows excellent redox characteristics with high oxidation current density (310 µA.cm ‐2 at 0.43 V vs. Ag/AgCl) and lower onset potential (0.22 V vs. Ag/AgCl). Additionally, Ni 1.5 Mn 1.5 O 4 exhibits moderate Tafel slope (78 mV.dec ‐1 ) and is electrochemically stable as confirmed from chronoamperometry, indicating its potential for glycine oxidation. The linear dependence of the oxidation current with glycine concentration is signifying that the overall process is diffusion controlled. The electrochemical results suggest that bimetallic mixed Mn and Ni oxides are promising glycine oxidation catalyst, which may be attributed to the cooperative effect between different Ni and Mn elements.

中文翻译：

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双金属镍锰氧化物催化剂对甘氨酸的电化学氧化

简单的无模板水热路径，然后在空气中进行高温（800°C）退火，形成Ni-Mn双金属氧化物，即NiMn 2 O 4，Ni 1.5 Mn 1.5 O 4，MnNi 2 O 4，其特征在于XRD，拉曼，EDS和SEM分析。通过循环伏安法和线性扫描伏安法研究了这些金属氧化物在碱性条件下对甘氨酸分子氧化的电催化活性。在其他镍锰双金属氧化物和单金属氧化物（Mn 2 O 3，NiO）中，Ni 1.5 Mn 1.5 O 4具有出色的氧化还原特性，具有高氧化电流密度（0.43 V时相对于Ag / AgCl的310 µA.cm ‐2）和较低的启动电位（相对于Ag / AgCl为0.22 V）。此外，Ni 1.5 Mn 1.5 O 4具有适度的Tafel斜率（78 mV.dec -1），并且如计时电流法所证实，具有电化学稳定性，表明其潜在的甘氨酸氧化作用。氧化电流与甘氨酸浓度的线性关系表明整个过程是受扩散控制的。电化学结果表明，双金属混合的Mn和Ni氧化物是有前途的甘氨酸氧化催化剂，这可能归因于不同的Ni和Mn元素之间的协同作用。