Morphology and strain control of hierarchical cobalt oxide nanowire electrocatalysts via solvent effect
Morphology and strain control of hierarchical cobalt oxide nanowire electrocatalysts via solvent effect
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DOI：
10.1007/s12274-020-2983-6
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发表时间：
2020-08
期刊：
影响因子：
9.9
通讯作者：
Xiuming Bu;Xiongyi Liang;K. Egbo;Zebiao Li;Y. Meng;Quan Quan-Quan;Yang Yang Li-Yang;K. Yu;Chi‐Man Lawrence W
中科院分区：
文献类型：
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作者：
Xiuming Bu;Xiongyi Liang;K. Egbo;Zebiao Li;Y. Meng;Quan Quan-Quan;Yang Yang Li-Yang;K. Yu;Chi‐Man Lawrence W
设计出高效、低成本的析氧电催化剂对许多可再生能源的应用具有重要意义。特别是，应变工程已被证明是提高催化剂电化学性能的有力策略；然而，所需的复杂催化剂制备工艺限制了应变工程的实施。本文报道了一种简单的自模板方法，通过容易制备的草酸-硝酸钴（Co(NO3)2）复合纳米线的热氧化转化制备具有可调压缩应变的分层多孔co3o4纳米线（PNWs）。在理论和实验研究的基础上，选择合适的溶剂制备催化剂不仅对co3o4的分层结构演化至关重要，而且对其压缩表面应变的调节也至关重要。由于PNWs具有丰富的表面活性位点和优化的Co - d带中心，PNWs具有优异的析氧活性和稳定性，在10 mA·cm−2in 1 M KOH条件下，其过电位为319 mV，质量负载为0.553 mg·cm−2，甚至优于贵金属催化剂RuO2。这项工作提供了一个具有成本效益的多孔co3o4纳米线制备实例，以及一种有前途的表面应变改性方法，以提高电化学性能。
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 Co3O4nanowires (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 Co3O4but 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−2in 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 Co3O4nanowire preparation as well as a promising method for modification of surface strain for the enhanced electrochemical performance.