Transition metal sulfides (TMSs) are promising electrocatalysts for boosting oxygen evolution reaction (OER) but their poor stability hinders the practical applications. Herein, a mesoporous CoS/MoS₂ polyhedron is synthesized for in situ embedded with CeO₂ nanoparticles (denoted as CeO₂@CoS/MoS₂). Electrochemical experimental results indicate that dispersion of a proper amount of CeO₂ (20 wt%) cocatalyst on the interface of CoS/MoS₂ has activated abundant Co/Mo sites and induced oxygen vacancies/defects to boost the OER activity. 20%CeO₂@CoS/MoS₂ displays excellent OER electrocatalytic performance in alkaline with an overpotential of 247 mV to reach the current density of 10 mA cm^-2 and a Tafel slope of 64 mV dec^-1. More importantly, the embedded CeO₂ particles have effectively prevented the binary metal sulfide from corrosion through Ce³⁺/Ce⁴⁺ switching, thus enhancing its stability and displaying a 12-hours continuous OER electrocatalysis at 10 mA cm^-2. Our result represents one of rare examples by assembling cocatalyst within mesoporous hetero-structural binary sulfides to improve the electrocatalytic performance for OER.

过渡金属硫化物（TMSs）是促进氧释放反应（OER）的有前途的电催化剂，但其稳定性差会阻碍实际应用。在此，合成了介孔CoS / MoS ₂多面体，以原位嵌入CeO ₂纳米颗粒（表示为CeO ₂ @ CoS / MoS ₂）。电化学实验结果表明，适量的CeO ₂（20 wt％）助催化剂在CoS / MoS ₂界面上的分散激活了丰富的Co / Mo位点，并诱导了氧空位/缺陷，从而提高了OER活性。20％CeO ₂ @ CoS / MoS ₂在碱性条件下表现出优异的OER电催化性能，过电位247mV以达到10mA cm ^-2的电流密度和64mV dec ^-1的Tafel斜率。更重要的是，嵌入的CeO ₂颗粒有效地防止了二元金属硫化物通过Ce ³⁺ / Ce ⁴⁺转换而腐蚀，从而增强了其稳定性，并在10 mA cm ^-2下显示了12小时连续OER电催化作用。我们的结果代表了罕见的例子之一，通过在中孔杂结构二元硫化物中组装助催化剂来提高OER的电催化性能。