writer：Wen-Jun Niu*, Qiao-Qiao Sun, Jin-Zhong He, Jiang-Lei Chen, Bing-Ni Gu, Ming-Jin Li
keywords：Tubular g-C3N4, Copper single atoms, Nitrogen-doped porous carbon, Cu-N4 active sites, Oxygen reduction reactions
source：期刊
specific source：Chemistry of Materials
Issue time：2022年

Here, copper single atoms anchored on nitrogen-doped porous carbon (Cu-N/PC) derived from zeolitic imidazolate frameworks (ZIFs) as highly efficient electrocatalyst for oxygen reduction reaction (ORR) were demonstrated. Specifically, as a nitrogen-rich bridge-molecule, tubular g-C3N4 (TCN) can trap free Cu ions through the electrostatic interaction in the initial stage. Then, the Cu ions doped TCN can be used to regulate the content of copper and nitrogen doping, the electronic structure, as well as the specific surface area and pore diameter of Cu-N/PC. As a result, the high density of exposed Cu-N4 active sites and the high level of porosity in Cu-N/PC may significantly enhance the ORR activity with a more positive onset potential (E₀ = 0.97 V vs. RHE) and half-wave potential (E_1/2 = 0.88 V) than the commercially available Pt/C catalyst (E₀ = 0.94, E_1/2 = 0.85 V). Furthermore, the homemade Zn-air battery (ZAB) equipped with Cu-N/PC is able to deliver excellent performance, including a peak power density of 215.8 mW cm^?2 and a specific capacity of 704.9 mAh g^?1 based on Zn anode, outperforming the Pt/C catalyst. The finding highlights a new guideline for constructing Cu-N/PC catalyst with a well-designed structure and superior property for advanced fuel cells cathode materials.