By designing the morphology and architecture of employed electrocatalysts, the development of high-performance hydrogen evolution reaction (HER) electrocatalysts for electrolytes with a wide pH range is practical significance for future energy conversion technologies. Herein, we synthesize an electrocatalyst composing of two-dimensional (2D) ultrathin ternary pyrite-type cobalt phosphosulfide nanosheets and conductive carbon black (CoPS NSs/C) by the one-step phosphosulfide process. Thanks to the introduction of the C, the composite not only presents a unique three-dimensional (3D) interconnected reticulum structure but also effectively reduces the thickness of nanosheets. The as-synthesized electrocatalyst exhibits remarkable small overpotential toward HER in wide pH range. Meanwhile, the electrocatalyst owns higher charge transfer rate and excellent stability. The good performance is mainly attributed to the combination of the advantages of both 2D nanosheets and 3D interconnected reticulum structure, which offers larger surface area, sufficient active sites and more contaction with electrolytes. This work provides a new method for preparing ultrathin ternary transition-metal phosphosulfide (TMPS) nanosheets, and offers a facile route for improving electrocatalytic activity by designing synergistic morphology of 2D and 3D.

通过设计所用电催化剂的形态和结构，开发用于宽pH范围的电解质的高性能氢析出反应（HER）电催化剂对于未来的能量转换技术具有实际意义。在这里，我们通过一步法硫化合成了二维（2D）超薄三元黄铁矿型磷化钴钴纳米片和导电炭黑（CoPS NSs / C）组成的电催化剂。由于引入了C，该复合材料不仅呈现出独特的三维（3D）互连网状结构，而且还有效地降低了纳米片的厚度。合成后的电催化剂在宽pH范围内对HER表现出极小的过电位。与此同时，该电催化剂具有较高的电荷转移速率和优异的稳定性。良好的性能主要归功于2D纳米片和3D互连网状结构的优点的结合，这提供了更大的表面积，足够的活性位点以及与电解质更多的接触。这项工作提供了一种制备超薄三元过渡金属磷硫化物（TMPS）纳米片的新方法，并提供了一种通过设计2D和3D协同形态来改善电催化活性的简便途径。