Abstract

Searching for inexpensive, efficient and durable electrocatalysts with earth-abundant elements toward the hydrogen evolution reaction (HER) is of vital importance for the future sustainable hydrogen economy, yet still remains a formidable challenge. Herein, a facile template-engaged strategy is demonstrated for the direct in-situ growth of Ni nanoparticles and N-doped carbon nanotubes on carbon nanorod substrates, forming a hierarchically branched architecture (abbreviated as Ni@N-C NT/NRs hereafter). The elaborate construction of such unique hierarchical structure with tightly encapsulated Ni nanoparticles and open configuration endows the as-fabricated Ni@N-C NT/NRs with abundant well-dispersed active sites, enlarged surface area, reduced resistances of charge transfer and mass diffusion, and reinforced mechanical robustness. As a consequence, the optimal Ni@N-C NT/NR catalyst demonstrates superior electrocatalytic activity with relatively low overpotential of 134 mV to deliver a current density of 10 mA·cm⁻² and excellent stability for HER in 0.1 M KOH, holding a great promise for practical scalable H₂ production. More importantly, this work offers a reliable methodology for feasible fabrication of robust high-performance carbon-based hierarchical architectures for a variety of electrochemical applications.

中文翻译：

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Ni纳米粒子包裹的N掺杂碳纳米管在碳纳米棒上的原位生长，用于有效的析氢电催化

摘要

寻找廉价，高效和耐用的，富含稀土元素的电催化剂以进行氢释放反应（HER），对于未来可持续的氢经济至关重要，但仍然是艰巨的挑战。在此，演示了一种针对直接原位的简便模板参与策略在碳纳米棒基底上生长Ni纳米颗粒和N掺杂的碳纳米管，形成分层分支的体系结构（以下简称为Ni @ NC NT / NRs）。紧密封装的Ni纳米颗粒和开放结构的这种独特的分层结构的精心构造赋予了制成的Ni @ NC NT / NRs足够丰富的活性位点，扩大了表面积，降低了电荷转移和质量扩散的阻力，并得到了增强机械坚固性。结果，最佳的Ni @ NC NT / NR催化剂显示出优异的电催化活性，相对较低的134 mV过电势，可提供10 mA·cm ^-2的电流密度，并在0.1 M KOH中对HER具有出色的稳定性，这具有很大的前景用于实用的可扩展H ₂生产。更重要的是，这项工作为可靠的方法提供了可靠的方法，可用于各种电化学应用的鲁棒高性能碳基分层体系结构的可行制造。