To enhance the intrinsic activity and the density of active sites of catalysts for the hydrogen evolution reaction (HER), a facile strategy of using an organic–inorganic precursor followed by carbonization is adopted to prepare ternary core–shell nanostructures composed of ultrafine hybrids of MoNi alloys and MoC_x nanoparticles encapsulated in N-doped carbon nanospheres (MoNi_x–MoC_x@NC). The well-defined pitaya-like nanostructures of MoNi_x–MoC_x nanoparticles encapsulated by N-doped carbon nanospheres can be obtained with MoNi_x–MoC_x hybrids as the core and ultrathin N-doped C layers as the shell. A triple synergistic effect has been achieved for the HER. The first synergistic effect from homogeneously dispersed MoNi_x alloys and MoC_x nanoparticles can improve the intrinsic activity and conductivity of MoC_x. The second synergistic effect from the MoNi_x–MoC_x and NC shell can enhance the density of active sites and conductivity of MoNi_x–MoC_x. The third synergistic effect from N-doped C can accelerate the charge transfer rate and improve close interaction between NC and MoNi_x–MoC_x. The MoNi_x–MoC_x@NC sample at an optimized low temperature of 700 °C exhibits excellent performance and long-term stability in both acidic and alkaline solution. It requires a lower overpotential of only 172 mV and 168 mV at 10 mA cm⁻² in acidic and alkaline solution, respectively. This work provides a new approach to design multiple synergistic effects from excellent catalytic interface through an organic–inorganic hybrid method for efficient electrocatalysis.

中文翻译：

---

封装在N掺杂的C纳米球中 的类似火龙果的MoNi _x -MoC _x杂化物具有三重协同效应，可有效释放氢†

为了提高用于氢释放反应（HER）的催化剂的固有活性和催化剂活性位点的密度，采用了一种简便的策略，即先使用有机-无机前驱物然后进行碳化，以制备由MoNi超细杂化物组成的三元核-壳纳米结构。合金和MoC _x纳米颗粒封装在N掺杂的碳纳米球中（MoNi _x –MoC _x @NC）。该明确定义的火龙果状MONI的纳米结构_X -MoC _X纳米颗粒包封的由N型掺杂的碳纳米球可以与MONI获得_X -MoC _X混合材料为核心，超薄N掺杂C层为壳。对于HER已经实现了三重协同作用。从均匀分散MONI第一协同效应_X合金和交通部_X纳米颗粒可以提高交通部的固有活性和电导率_X。从MONI第二协同效应_X -MoC _X和NC壳可以提高活性位点的MONI的密度和电导率_X -MoC _X。N掺杂的C产生的第三种协同效应可以加快电荷转移速率，并改善NC与MoNi _x -MoC _x之间的紧密相互作用。MoNi _x –MoC _x在优化的700°C低温下，@ NC样品在酸性和碱性溶液中均具有出色的性能和长期稳定性。在酸性和碱性溶液中，在10 mA cm ^-2时，仅需要较低的过电势，分别仅为172 mV和168 mV 。这项工作提供了一种新的方法，可以设计出色的催化界面，通过有机-无机杂化方法实现高效电催化的多种协同效应。