MOF‐Derived Hollow CoS Decorated with CeOx Nanoparticles for Boosting Oxygen Evolution Reaction Electrocatalysis

Transition‐metal sulfides (TMSs) have emerged as important candidates for oxygen evolution reaction (OER) electrocatalysts. Now a hybrid nanostructure has been decorated with CeOx nanoparticles on the surface of ZIF‐67‐derived hollow CoS through in situ generation. Proper control of the amount of CeOx on the surface of CoS can achieve precise tuning of Co2+/Co3+ ratio, especially for the induced defects, further boosting the OER activity. Meanwhile, the formation of protective CeOx thin layer effectively inhibits the corrosion by losing cobalt ion species from the active surface into the solution. It is thus a rare example of a hybrid hetero‐structural electrocatalyst with CeOx NPs to improve the performance of the hollow TMS nanocage. A hybrid nanostructure decorated with CeOx nanoparticles on the surface of MOF‐derived hollow CoS was designed and fabricated. It not only boosts the oxygen evolution reaction (OER) electrocatalytic process effectively, but also improves stability significantly. Precise tuning of Co2+/Co3+ ratio and induced defects can be achieved. The formation of a protective CeOx thin layer inhibits the oxidation of CoS and loss of cobalt.