Efficient methods are urgently required for developing electrocatalysts with superior activities and practical applications. In this work, a novel pure ternary CoFeCr hydroxide was synthesized on carbon paper using a low-temperature (60 °C) hydrothermal approach. The OER performances of the CoFeCr hydroxides with different atomic ratios were systematically investigated. Intriguingly, the optimized trimetallic CoFeCr-6:2:1 electrocatalyst exhibited significantly improved OER performance with a small overpotential of 260 mV at 10 mA cm⁻² and a low Tafel slope of 40.1 mV dec⁻¹ under alkaline conditions. Combined experimental and DFT+U computational studies revealed that Fe was the active site and the excellent OER activity could be attributed to the electronic structure regulation effect via the introduction of Cr, which on the one hand improved the d-band center position of the Fe sites and on the other hand decreased the band gap of the sample. This regulation effect optimized the adsorption of oxygen species and efficiently accelerated the oxygen evolution kinetics and charge transfer kinetics, thus enhancing the OER performance of CoFeCr-6:2:1. Our results provide both experimental and theoretical basis for the further exploration of efficient hydroxide electrocatalysts for energy-related applications.

中文翻译：

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低温合成的三金属CoFeCr氢氧化物电催化剂，用于通过调节活性位的电子结构来加速水氧化

迫切需要有效的方法来开发具有优异活性和实际应用的电催化剂。在这项工作中，使用低温（60°C）水热方法在碳纸上合成了新型的纯三元CoFeCr氢氧化物。系统地研究了不同原子比的CoFeCr氢氧化物的OER性能。有趣的是，优化的三金属CoFeCr-6：2：1电催化剂显示出显着改善的OER性能，在10 mA cm ^-2时有260 mV的小过电位，在40.1 mV dec ^-1的低Tafel斜率在碱性条件下。结合实验和DFT + U的计算研究显示，铁是活性位点和优异的OER活性可能归因于电子结构调节作用通过引进的Cr，其中，一方面提高了Fe的d带中心位置的另一方面，减小了样品的带隙。这种调节作用优化了氧的吸附，并有效地加速了氧的释放动力学和电荷转移动力学，从而提高了CoFeCr-6：2：1的OER性能。我们的研究结果为进一步探索与能源相关的高效氢氧化物电催化剂提供了实验和理论基础。