In-situ Synthesis of Mott-Schottky Co/Co9S8 Heterojunction Anchored on Carbon Nanosheets for Efficient Electrochemical Performance
FANG Yu1,2, LI Jing1,2, KONG Weichao1, ZHOU Xue1,2, XU Lin1,2,*, SUN Dongmei1,2,*, TANG Yawen1,2
1 School of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, China 2 Jiangsu Key Laboratory of New Power Batteries, Nanjing 210023, China
Abstract: Using K3[Co(CN)6] as Co source, thiurea as S source and natural hydrophilic polymer chitosan rich in -OH and -NH2 as carbon source, the Co precursor and S source were uniformly distributed in the C precursor by forming CS-K3[Co(CN)6] hydrogel. The main driving force of hydrogel formation is the coordination crosslinking of metal Co ions with -NH2 in chitosan and the bridging between Co ions via -CN. Thanks to the uniformly dispersed precursor and the catalysis of the Co formed at the initial stage of subsequent pyrolysis, N, S co-doped carbon nanosheets with encaged Co/Co9S8 heterojunction (Co/Co9S8@N, S-CNSs) were constructed in situ by simply regulating the atomic ratio of Co to S. The morphology, composition and structure of the prepared electrocatalysts and the oxygen evolution reaction performance were analyzed with SEM, TEM, BET, XRD, Raman, XPS and electrochemical workstations. The results show that the Mott-Schottky type Co/Co9S8 interface effectively regulates the electronic structure and charge-transport characteristics of the active center. The loading of two-dimensional doped porous carbon nanosheets makes the active sites more evenly dispersed, while providing high-speed electron and mass transfer channels, as well as avoiding the migration and aggregation of active sites during the catalytic process. The synergistic action of these two allows the proposed Co/Co9S8@N, S-CNSs catalyst have better electrocatalytic performances. At a current density of 10 mA·cm-2, the overpotential of the proposed catalyst for basic oxygen evolution reaction/OER is only 304 mV, which is better than that of the commercial RuO2. This study is helpful for the development of cheap transition metal catalysts with excellent electrocatalytic properties.
通讯作者:
*徐林,南京师范大学化学与材料科学学院教授、博士研究生导师。2004年毕业于南通大学,获得学士学位。2010年毕业于南京大学,获得博士学位。2010年至2015年在美国印第安纳大学和新加坡南洋理工大学进行博士后研究。2015年至今在南京师范大学工作。目前主要从事纳米功能材料及其能源转化与储存的研究。发表论文100余篇,其中包含Advanced Functional Materials、Advanced Science、 Nano Research、 Nanoscale、ACS Applied Materials & Interfaces、Chemistry-A European Journal、The Journal of Physical Chemistry C等。xulin001@njnu.edu.cn 孙冬梅,南京师范大学化学与材料科学学院教授、博士研究生导师。1991毕业于南京师范大学化学系获学士学位;2005年毕业于中国科学院长春应用化学研究所获博士学位。2006—2008年先后在美国University of Hawaii at Manoa和英国University College London进行博士后研究。2019—2020年在澳大利亚The Australian National University作为访问学者访学一年。目前主要从事纳米电催化、燃料电池、新型氧化还原酶的设计及酶的三维结构与功能的相互关系等研究。发表SCI收录论文100余篇,参与编著中英文专业书籍2部。sundongmei@njnu.edu.cn
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2024, Vol. 38 
