Synthesis of free-standing metal sulfide nanoarrays via anion exchange reaction and their electrochemical energy storage application

• Main Authors: Xia, Xinhui, Zhu, Changrong, Luo, Jingshan, Zeng, Zhiyuan, Guan, Cao, Ng, Chin Fan, Zhang, Hua, Fan, Hong Jin
• Other Authors: School of Materials Science & Engineering
• Format: Article
• Language: English
• Published: 2014
• Subjects: DRNTU::Engineering::Materials
• Online Access: https://hdl.handle.net/10356/102772; http://hdl.handle.net/10220/19109
• Institution: Nanyang Technological University

Metal sulfides are an emerging class of high-performance electrode materials for solar cells and electrochemical energy storage devices. Here, a facile and powerful method based on anion exchange reactions is reported to achieve metal sulfide nanoarrays through a topotactical transformation from their metal oxide and hydroxide pre-forms. Demonstrations are made to CoS and NiS nanowires, nanowalls, and core-branch nanotrees on carbon cloth and nickel foam substrates. The sulfide nanoarrays exhibit superior redox reactivity for electrochemical energy storage. The self-supported CoS nanowire arrays are tested as the pseudo-capacitor cathode, which demonstrate enhanced high-rate specific capacities and better cycle life as compared to the powder counterparts. The outstanding electrochemical properties of the sulfide nanoarrays are a consequence of the preservation of the nanoarray architecture and rigid connection with the current collector after the anion exchange reactions.