Cobalt nanoparticles embedded in porous N-doped carbon support as a superior catalyst for the p-nitrophenol reduction

[Display omitted] •New catalyst with low Co-content and high activity was obtained.•Pure cobalt and bimetallic zinc/cobalt ZIF-67 were used as precursors.•Polyvinylidene fluoride was used to provide a porous carbon shell after annealing.•This shell promotes the p-nitrophenol catalytic reduction. We report the synthesis of a new effective cobalt-based composite for catalytic reduction of water pollutant - p-nitrophenol. ZIF-67 and its Zn-substituted analog have been used as precursors for the catalyst preparation. Their pyrolysis has resulted in cobalt nanoparticles embedded into N-doped carbon substrates. We have used polyvinylidene fluoride (PVDF) as an additive to ZIF-substrates to produce mesoporous carbon shells on the surface of the catalysts. We have found that PVDF-additive enhanced the catalytic properties of the obtained composite material. Firstly, this additive reduces the total cobalt concentration in the composite by increasing carbon content. Secondly, a porous carbon shell improves the rate of catalytic reactions. According to the experimental data, PVDF additive has allowed us to obtain materials with lower Co-content but with high catalytic activity towards p-nitrophenol reduction.