The rational design and strategy of obtaining stable bifunctional electrocatalysts with unique functionalities are prerequisite to achieving robust catalytic activity. In this study, a composition‐controlled partial sulfurization/phosphorization strategy to synthesize a doughnut‐like 3D heterostructured electrocatalyst for overall water splitting is proposed, wherein core–shell 2D CoS_1−x P_x nanosheets decorated with N‐doped carbon are self‐assembled to form a hierarchical 3D architecture. The composition and phase structure in core–shell CoS_1−x P_x can be readily modified by controlling the liquid phase sulfurization and subsequent phosphorization, thereby modifying the electronic structure and activating the intrinsic active sites. The resulting CoS_1−x P_x benefits from the unique structural features including high accessible active surface area, adequate amount of reactive sites, intimate interfacial coupling between the components, interconnected electron highway, and accelerated charge/mass transfer ability. Consequently, the optimized CoS_0.46P_0.54 electrocatalyst achieves a catalytic current density of 10 mA cm⁻² at overpotentials as low as 101 and 302 mV for hydrogen evolution reaction and oxygen evolution reaction, respectively, with outstanding long‐term operational stability in alkaline solution. The CoS_0.46P_0.54 couple enables an alkaline water electrolysis with a current density of 10 mA cm⁻² at a low cell voltage of 1.62 V, comparable to that of the RuO₂||Pt/C couple (1.6 V).

中文翻译：

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用于整体水分解的堆叠式核-壳CoS1-xPx异质结构纳米片的分层结构双功能电催化剂

获得具有独特功能的稳定双功能电催化剂的合理设计和策略是实现强大的催化活性的前提。在这项研究中，提出了一种成分控制的部分硫化/磷化策略，以合成用于整个水分解的甜甜圈状3D异质结构电催化剂，其中，用N掺杂碳修饰的核壳2D CoS ₁ - _x P _x 纳米片是自组装的。组装以形成分层的3D架构。核-壳型CoS ₁ - _x P _x的组成和相结构 通过控制液相硫化和随后的磷化，可以容易地修饰R 2，从而修饰电子结构并激活固有活性位。所得的CoS _{1- x} P _x 得益于独特的结构特征，包括高可及活性表面积，足够数量的反应位点，组件之间的紧密界面耦合，互连的电子高速公路以及加速的电荷/质量转移能力。因此，优化的CoS _0.46 P _0.54电催化剂实现了10 mA cm ^-2的催化电流密度氢气分解反应和氧气分解反应的低电势分别低至101和302 mV，在碱性溶液中具有出色的长期运行稳定性。与RuO ₂ || Pt / C对（1.6 V）相比，CoS _0.46 P _0.54对能够在1.62 V的低电池电压下以10 mA cm ^-2的电流密度进行碱性水电解。