Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, Department of Chemistry and Chemical Engineering , Huazhong University of Science & Technology , Wuhan 430074 , PR China.
School of Chemistry and Environmental Engineering , Wuhan Institute of Technology , Wuhan 430205 , PR China.
ACS Appl Mater Interfaces. 2018 Oct 3;10(39):33124-33134. doi: 10.1021/acsami.8b07343. Epub 2018 Sep 19.
It is a critical challenge to construct efficient precious-metal-free bifunctional oxygen electrocatalysts for fuel cell and metal-air batteries via structural and component engineering. Herein, a one-dimensional mesoporous double-layered tubular structure, where CoS nanocrystals are incorporated into nitrogen, sulfur codoped carbon, is successfully synthesized via the coordinated-assisted polymerization and sacrificial template methods. The double-layered tubular structure provides for a large electrochemically active surface area and promotes fast mass transfer. Cobalt oxides/oxyhydroxides, which are evolved from the sulfides during the catalytic processes, as the main active sites efficiently catalyze the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), in cooperation with the Co-N-C and heteroatom-induced active sites. Hence, it demonstrates excellent bifunctional electrocatalytic activity with the overvoltage between the OER potential at 10 mA cm ( E) and ORR half-wave potential ( E) of 0.707 V, which is superior to most of precious-metal-free bifunctional oxygen electrocatalysts reported recently, as well as the state-of-art Pt/C and RuO catalysts.
通过结构和组分工程来构建用于燃料电池和金属-空气电池的高效无贵金属双功能氧电催化剂是一个关键挑战。在此，通过配位聚合和牺牲模板法成功合成了一维介孔双层管状结构，其中嵌入了 CoS 纳米晶的氮、硫共掺杂碳。双层管状结构提供了大的电化学活性表面积并促进了快速传质。在催化过程中，硫化物演变而来的钴氧化物/氢氧化物作为主要活性位点，与 Co-N-C 和杂原子诱导的活性位点协同作用，高效地催化氧还原反应（ORR）和析氧反应（OER）。因此，它表现出优异的双功能电催化活性，其在 10 mA cm（E）处的 OER 电位和 ORR 半波电位（E）之间的过电势为 0.707 V，优于最近报道的大多数无贵金属双功能氧电催化剂以及最先进的 Pt/C 和 RuO 催化剂。
