Hydrothermal-Induced Formation of Well-Defined Hollow Carbons with Curvature-Activated N?C Sites for Zn–Air Batteries |
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| Authors: | Chunxiao Li Wanli Xu Liangwen Ye Prof Jingjun Liu Prof Feng Wang |
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| Institution: | State Key Laboratory of Chemical Resource Engineering, Beijing Key Laboratory of Electrochemical Process and Technology for, Materials, Beijing University of Chemical Technology, Beijing, 100029 P. R. China |
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| Abstract: | Metal-free carbons have been regarded as one of the promising materials alternatives to precious-metal catalysts for oxygen reduction reaction (ORR) due to their high activity and stability. In this paper, well-defined N-doped hollow carbons (NHCs) are firstly synthesized by using an ammonia-based hydrothermal synthesis that is environmentally friendly and suitable for mass production in industry and a commercial black carbon as raw material. Moreover, the shell thickness of the NHCs can be easily tuned by this hydrothermal strategy. Zn–air battery test results reveal shell thickness-dependent activity and durability for ORR over the NHCs, which exceeds that obtained by commercial Pt/C (20 wt %). The enhanced battery performance can be attributed to the curvature-activated N–C moieties on the hollow carbon surface, which served as the main active sites for ORR as evidenced by DFT calculations. The proposed approach may open a way for designing curved hollow carbons with high graphitization degree and dopant nitrogen level for metal–air batteries or fuel cells. |
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| Keywords: | active sites batteries hollow carbons hydrothermal zinc–air batteries |
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