Designing highly efficient and low-cost electrocatalysts for oxygen evolution reaction is important for many renewable energy applications. In particular, strain engineering has been demonstrated as a powerful strategy to enhance the electrochemical performance of catalysts; however, the required complex catalyst preparation process restricts the implementation of strain engineering. Herein, we report a simple self-template method to prepare hierarchical porous Co₃O₄ nanowires (PNWs) with tunable compressive strain via thermal-oxidation-transformation of easily prepared oxalic acid-cobalt nitrate (Co(NO₃)₂) composite nanowires. Based on the complementary theoretical and experimental studies, the selection of proper solvents in the catalyst preparation is not only vital for the hierarchical structural evolution of Co₃O₄ but also for regulating their compressive surface strain. Because of the rich surface active sites and optimized electronic Co d band centers, the PNWs exhibit the excellent activity and stability for oxygen evolution reaction, delivering a low overpotential of 319 mV at 10 mA·cm⁻² in 1 M KOH with a mass loading 0.553 mg·cm⁻², which is even better than the noble metal catalyst of RuO₂. This work provides a cost-effective example of porous Co₃O₄ nanowire preparation as well as a promising method for modification of surface strain for the enhanced electrochemical performance.

设计用于氧气析出反应的高效，低成本电催化剂对于许多可再生能源应用而言非常重要。特别是，应变工程已被证明是增强催化剂电化学性能的强大策略。然而，所需的复杂催化剂制备过程限制了应变工程的实施。本文中，我们报告了一种简单的自模板方法，该方法通过容易制备的草酸-硝酸钴（Co（NO ₃）₂）的热氧化转化来制备具有可调压缩应变的分层多孔Co ₃ O ₄纳米线（PNW）。）复合纳米线。基于互补的理论和实验研究，在催化剂制备中选择合适的溶剂不仅对于Co ₃ O ₄的分层结构演化至关重要，而且对于调节其压缩表面应变也至关重要。由于具有丰富的表面活性位点和优化的电子Co d能带中心，PNW在氧气释放反应中表现出出色的活性和稳定性，在1 M KOH中以10 mA·cm ^-2的质量负载提供了319 mV的低过电势0.553mg·cm ^-2，甚至优于RuO ₂的贵金属催化剂。这项工作提供了一个具有成本效益的多孔Co ₃ O ₄实例。 纳米线的制备以及用于改善表面应变以增强电化学性能的有前途的方法。