Atomic Bridging of Metal-Nitrogen-Carbon toward Efficient Integrated Electrocatalysis

摘要

The rational design of robust electrocatalysts for efficient integrated devicesis crucial to enhance energy conversion performance. The coordination oforganic ligands with metal ions provides high flexibility to anchor metalatoms among carbon materials. Herein, the atomic anchoring of Zn andNi atoms into N-doped carbon networks with adjustable atomic structureis developed by the facile pyrolysis of metal-organic framework nanoplatesin the presence of dicyandiamide. Theoretical calculations reveal thedescriptor-based design principles to adjust the bridging structures of metalnitrogen-carbon moieties with changing d-band centers, thereby improvingelectrocatalytic performance. The resulting electrocatalyst displays good multipleelectrocatalytic activities for carbon dioxide reduction, oxygen reduction,and evolution reactions, enabling the fabrication of integrated energy devices.Importantly, the CO_2-H_2O overall splitting with the as-prepared electrocatalystshas been driven by the commercial solar cell and the zinc-air batteryassembled with the same catalyst respectively, showing high CO faradaicefficiency up to 90%. Especially, the overall solar-to-CO conversion efficiencyis up to 13% and the corresponding utilization efficiency of solar-to-electricitycan reach 54.4%, demonstrating the large promising space to chase the limitthat solar cells can possibly achieve. This work provides new opportunities tomodulate the atomic bridging structure of metal-nitrogen-carbon for integratedelectrolysis.