Co/ZnO/N-C composites obtained by ZIF derived from Co-Zn oxides as highly efficient catalyst for reduction of p-nitrophenol

Zinc oxide (ZnO) and cobalt (Co)-ZnO nanocomposites were first reacted with 2-Methylimidazole to synthesize the zeolitic imidazole frameworks as precursors. After calcination in nitrogen, the ZnO/N-C and Co/ZnO/N-C composites were received, respectively. The structure and composition of the samples at different stages were characterized in order to illustrate the transformation process. Finally, the ZnO/N-C and Co/ZnO/N-C composites were employed as catalysts for the hydrogenation of p-nitrophenol by sodium borohydride. The catalytic results suggested that the Co/ZnO/N-C composite with a proper amount of metallic cobalt, better dispersion, small size, and synergetic effect of N doping on carbon displayed a much more efficient catalytic ability for the reduction of p-nitrophenol in comparison with the ZnO/N-C composite as well as the Co/N-C composite synthesized by ZIF-67. The present work would provide further insight into the design of metal-carbon-based materials from the corresponded metal-organic frameworks derived from the relevant metal oxides and development of their applications from the aspect of interface and colloid chemistry. [GRAPHICS] .

Automated summary

In this study, zeolitic imidazole frameworks were synthesized from ZnO and Co-ZnO nanocomposites, resulting in ZnO/N-C and Co/ZnO/N-C composites which were employed as catalysts for the reduction of p-nitrophenol. The Co/ZnO/N-C composite exhibited a more efficient catalytic ability, highlighting the importance of metallic cobalt, dispersion, size, and N doping on carbon for catalytic performance.