Trifunctional robust electrocatalysts based on 3D Fe/N‐doped carbon nanocubes encapsulating Co4N nanoparticles for efficient battery‐powered water electrolyzers
Hyung Wook Choi,
Hongdae Lee,
Jun Lu,
Seok Bin Kwon,
Dong In Jeong,
Beum Jin Park,
Jiwon Kim,
Bong Kyun Kang,
Gun Jang,
Dae Ho Yoon,
Ho Seok Park
Affiliations
Hyung Wook Choi
SKKU Advanced Institute of Nano Technology (SAINT) Sungkyunkwan University Suwon‐si Gyeonggi‐do Republic of Korea
Hongdae Lee
School of Chemical Engineering Sungkyunkwan University Suwon‐si Gyeonggi‐do Republic of Korea
Jun Lu
School of Chemical Engineering Sungkyunkwan University Suwon‐si Gyeonggi‐do Republic of Korea
Seok Bin Kwon
School of Advanced Materials Science and Engineering Sungkyunkwan University Suwon‐si Gyeonggi‐do Republic of Korea
Dong In Jeong
School of Advanced Materials Science and Engineering Sungkyunkwan University Suwon‐si Gyeonggi‐do Republic of Korea
Beum Jin Park
School of Chemical Engineering Sungkyunkwan University Suwon‐si Gyeonggi‐do Republic of Korea
Jiwon Kim
School of Advanced Materials Science and Engineering Sungkyunkwan University Suwon‐si Gyeonggi‐do Republic of Korea
Bong Kyun Kang
Department of Electronic Materials, Devices, and Equipment Engineering Soonchunhyang University Asan City Chungnam Republic of Korea
Gun Jang
School of Chemical Engineering Sungkyunkwan University Suwon‐si Gyeonggi‐do Republic of Korea
Dae Ho Yoon
SKKU Advanced Institute of Nano Technology (SAINT) Sungkyunkwan University Suwon‐si Gyeonggi‐do Republic of Korea
Ho Seok Park
SKKU Advanced Institute of Nano Technology (SAINT) Sungkyunkwan University Suwon‐si Gyeonggi‐do Republic of Korea
Abstract Herein, we have designed a highly active and robust trifunctional electrocatalyst derived from Prussian blue analogs, where Co4N nanoparticles are encapsulated by Fe embedded in N‐doped carbon nanocubes to synthesize hierarchically structured Co4N@Fe/N–C for rechargeable zinc–air batteries and overall water‐splitting electrolyzers. As confirmed by theoretical and experimental results, the high intrinsic oxygen reduction reaction, oxygen evolution reaction, and hydrogen evolution reaction activities of Co4N@Fe/N–C were attributed to the formation of the heterointerface and the modulated local electronic structure. Moreover, Co4N@Fe/N–C induced improvement in these trifunctional electrocatalytic activities owing to the hierarchical hollow nanocube structure, uniform distribution of Co4N, and conductive encapsulation by Fe/N–C. Thus, the rechargeable zinc–air battery with Co4N@Fe/N–C delivers a high specific capacity of 789.9 mAh g−1 and stable voltage profiles over 500 cycles. Furthermore, the overall water electrolyzer with Co4N@Fe/N–C achieved better durability and rate performance than that with the Pt/C and IrO2 catalysts, delivering a high Faradaic efficiency of 96.4%. Along with the great potential of the integrated water electrolyzer powered by a zinc–air battery for practical applications, therefore, the mechanistic understanding and active site identification provide valuable insights into the rational design of advanced multifunctional electrocatalysts for energy storage and conversion.