Co@Co Cages Engineered from Hollowing MOFs for Enhanced Hydrogen Evolution Reaction Performance

Advances in hollow engineering ofmetal-organicframeworks(MOFs) have enabled a variety of applications in catalysts, sensors,and batteries, but the hollow derivatives are often limited to hydroxides,oxides, selenides, and sulfides with the presence of additional elementsfrom the environment. Here we have successfully synthesized hollowmetallic Co@Co cages through a facile two-step strategy. Interestingly,the Co@Co(C) cages with a small amount of residual carbon show excellentcatalytic performance due to the abundant exposed active sites andfast charge transfer. During the hydrogen evolution reaction, theoverpotential of Co@Co(C) is as low as similar to 54 mV at the currentdensity of 10 mA cm(-2), which is close to that of similar to 38 mV for the Pt/C electrodes. The two-step synthesis strategyopens up opportunities for increasing the number of catalytic activesites and rates of charge/mass transfer while pushing the limits ofmaterials utilization beyond that achieved in existing MOF-based nanostructures.

Automated summary

Hollow metallic Co@Co cages were successfully synthesized using a simple two-step strategy, showing excellent catalytic performance due to abundant exposed active sites and fast charge transfer. The low overpotential of Co@Co(C) in the hydrogen evolution reaction suggests its potential as a catalyst comparable to Pt/C electrodes. This two-step synthesis strategy opens up opportunities for improving catalytic activity and charge/mass transfer rates in MOF-based nanostructures.