Encapsulation of Cobalt Oxide in Conjugated Network Polymer as a Catalyst for Hydrogen Evolution

Abstract

In the hydrogen evolution field, cobalt oxides have been recognized as a promising non-precious transition metal catalyst. In addition, two-dimensional (2-D) network polymer supported cobalt oxide catalysts with good crystallinity are highly anticipated to enhance catalytic performance. Here, we report the fabrication of a 2D nitrogenated network polymer-encapsulated cobalt oxide (Co@C2N) catalyst via an in-situ solvothermal synthesis. Co@C2N exhibits outstanding catalytic activities for hydrogen (H2) generation from the hydrolysis of alkaline sodium borohydride (NaBH4) solutions. The rate of maximum hydrogen generation is comparable to the best reported values for catalysts containing other noble metals in alkaline solutions. Furthermore, Co@C2N can also catalyze the in-situ reduction of a nitro group into an amino group (4-nitrophenol to 4-aminophenol) in the presence of NaBH4. The origin of high catalytic activity with enhanced stability could be due to the strong interaction between cobalt oxide nanoparticle and C2N framework, which contains large portion of nitrogen.