The development of durable, low‐cost, and efficient photo‐/electrolysis for the oxygen and hydrogen evolution reactions (OER and HER) is important to fulfill increasing energy requirements. Herein, highly efficient and active photo‐/electrochemical catalysts, that is, CoMn‐LDH@g‐C₃N₄ hybrids, have been synthesized successfully through a facile in situ co‐precipitation method at room temperature. The CoMn‐LDH@g‐C₃N₄ composite exhibits an obvious OER electrocatalytic performance with a current density of 40 mA cm⁻² at an overpotential of 350 mV for water oxidation, which is 2.5 times higher than pure CoMn‐LDH nanosheets. For HER, CoMn‐LDH@g‐C₃N₄ (η₅₀=−448 mV) requires a potential close to Pt/C (η₅₀=−416 mV) to reach a current density of 50 mA cm². Furthermore, under visible‐light irradiation, the photocurrent density of the CoMn‐LDH@g‐C₃N₄ composite is 0.227 mA cm⁻², which is 2.1 and 3.8 time higher than pristine CoMn‐LDH (0.108 mA cm⁻²) and g‐C₃N₄ (0.061 mA cm⁻²), respectively. The CoMn‐LDH@g‐C₃N₄ composite delivers a current density of 10 mA cm⁻² at 1.56 V and 100 mA cm⁻² at 1.82 V for the overall water‐splitting reaction. Therefore, this work establishes the first example of pure CoMn‐LDH and CoMn‐LDH@g‐C₃N₄ hybrids as electrochemical and photoelectrochemical water‐splitting systems for both OER and HER, which may open a pathway to develop and explore other LDH and g‐C₃N₄ nanosheets as efficient catalysts for renewable energy applications.

中文翻译：

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双功能CoMn层状双氢氧化物@石墨C3N4纳米杂化物与高效光电化学总水分解的耦合

为满足氧气和氢气释放反应（OER和HER）的需要，开发持久，低成本和高效的光/电解对于满足不断增长的能源需求非常重要。在此，高效，活性的光/电化学催化剂，即CoMn-LDH @ g-C ₃ N ₄杂化体，已通过一种简便的室温共沉淀方法成功地合成。CoMn-LDH @ g-C ₃ N ₄复合材料具有明显的OER电催化性能，在水氧化的超电势为350 mV时电流密度为40 mA cm ^-2，比纯CoMn-LDH纳米片高2.5倍。对于HER，CoMn‐LDH @ g‐C ₃ N ₄（η ₅₀ = -448毫伏）需要一个电位接近的Pt / C（η ₅₀ = -416毫伏），以达到为50mA cm 2的电流密度²。此外，在可见光照射下，CoMn-LDH @ g-C ₃ N ₄复合材料的光电流密度为0.227 mA cm ^-2，比原始CoMn-LDH（0.108 mA cm ^-2）高2.1倍和3.8倍和g‐C ₃ N ₄（0.061 mA cm ^-2）。CoMn-LDH @ g-C ₃ N ₄复合材料在1.56 V和100 mA cm ^-2时提供10 mA cm ^-2的电流密度整个水分解反应在1.82 V下进行。因此，这项工作建立了纯CoMn-LDH和CoMn-LDH @ g-C ₃ N ₄杂化物作为OER和HER的电化学和光电化学水分解系统的第一个实例，这可能为开发和探索其他LDH开辟道路和g‐C ₃ N ₄纳米片作为可再生能源应用的有效催化剂。