Electrocatalytic overall water splitting is always holding great promise in renewable energy field. It is crucial to fabricate low-cost, earth-abundant and robust bi-functional electrocatalysts for both hydrogen evolution and oxygen evolution reactions. Herein, we report a polyoxometalates (POMs)-based molecular approach to construct Co promoting MoS₂-based nanosheets Co₅Mo₁₀S_x employing well-defined Co₃[Co₂Mo₁₀O₃₈H₄] as superior precursor. The CoMo-POMs act as pre-assembling molecular platform for the construction and regulation of CoS₂-MoS₂ heteronanostructure (CoMoS active sites) through precise engineering with atomic level. The Co₅Mo₁₀S_x exhibited excellent bi-functional electrocatalytic activity in alkaline solution, with only 36 mV and 153 mV overpotential to achieve 10 mA cm^-2 current density for HER and OER, respectively. We demonstrate a two-electrode cell performing water electrolysis in alkaline condition, delivering a current density of 10 mA cm^-2 at low cell voltage of 1.51 V. Combined with the theoretical calculations, the superior performance can be attributed to enhanced intrinsic catalytic activity of CoMoS sites, synergistic effect of heterostructure, abundant and defect-rich heterogeneous interfaces. This study provides a feasible strategy to rational design and controllable fabrication of efficient electrocatalysts for renewable energy applications.

在可再生能源领域，电催化总水分解技术一直具有广阔的前景。对于氢析出和氧析出反应而言，制造低成本，富含地球的且坚固的双功能电催化剂至关重要。在这里，我们报告了一种基于多金属氧酸盐（POMs）的分子方法，以定义明确的Co ₃ [Co ₂ Mo ₁₀ O ₃₈ H ₄ ]为上级前驱体，构建了基于Co的MoS ₂纳米片Co ₅ Mo ₁₀ S _x。CoMo-POM充当用于组装和调节CoS ₂ -MoS _2的预组装分子平台通过原子级的精确工程实现异质结构（CoMoS活性位点）。Co ₅ Mo ₁₀ S _x在碱性溶液中表现出优异的双功能电催化活性，仅过电位为36 mV和153 mV，以实现HER和OER的电流密度分别为10 mA cm ^-2。我们演示了在碱性条件下执行水电解的两电极电池，可提供10 mA cm ^-2的电流密度在低电池电压为1.51 V时。结合理论计算，其优越的性能可归因于CoMoS位点的固有催化活性增强，异质结构的协同效应，丰富的和缺陷丰富的异质界面。这项研究为合理设计和可控制地制造可再生能源应用的高效电催化剂提供了可行的策略。