Alkali etching zinc and manganese silicates derived from natural green algaes for supercapacitors with enhanced electrochemical properties

Shaoqing Zhang; Jiqi Zheng; Jumeng Wei; Yifu Zhang; Feier Niu; Yanping Wang; Haoran Yan; Zirong Li; Changgong Meng

doi:10.1016/j.jcis.2022.05.016

Alkali etching zinc and manganese silicates derived from natural green algaes for supercapacitors with enhanced electrochemical properties

J Colloid Interface Sci. 2022 Oct:623:135-145. doi: 10.1016/j.jcis.2022.05.016. Epub 2022 May 10.

Authors

Shaoqing Zhang¹, Jiqi Zheng², Jumeng Wei³, Yifu Zhang⁴, Feier Niu³, Yanping Wang³, Haoran Yan³, Zirong Li³, Changgong Meng⁵

Affiliations

¹ College of Chemistry and Materials Engineering, Anhui Science and Technology University, Bengbu 239000, China. Electronic address: zhangsq@ahstu.edu.cn.
² College of Environment and Chemical Engineering, Dalian University, Dalian 116622, China.
³ College of Chemistry and Materials Engineering, Anhui Science and Technology University, Bengbu 239000, China.
⁴ School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China.
⁵ College of Environment and Chemical Engineering, Dalian University, Dalian 116622, China; School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China. Electronic address: cgmeng@dlut.edu.cn.

PMID: 35576645
DOI: 10.1016/j.jcis.2022.05.016

Abstract

A facile novel method of alkali etching was proposed to enhance the application of metal-silicates in supercapacitors. First, 3D N, S, P-doped C-zinc-silicate (C-ZnSi), and C-manganese-silicate (C-MnSi) were derived from calcined green algaes (GAs) in a N₂ atmosphere. Second, the synthesized products were soaked in a 3.0 M NaOH aqueous solution for alkali etching (soaked for 6, 12 and 24 h) to obtain the etching metal silicates (e-C-ZnSi and e-C-MnSi). This method can yield a higher specific surface area and more pores, and this in turn can improve the electrochemical performance. In the three-electrode system, e-C-ZnSi and e-C-MnSi, which were soaked in NaOH solution for 12 h, exhibited the highest specific capacitances and cycling performance. Solid-state hybrid supercapacitor (HSC) devices were manufactured using C-MSi, e-C-MSi (M = Zn and Mn), and activated carbon (AC) (denoted as C-MSi//AC and e-C-MSi//AC). In the two-electrode system, the e-C-MSi//AC HSC devices exhibited higher areal specific capacitances and energy densities and better cycle performance than those of C-MSi//AC, especially e-C-MSi//AC-12 h HSC devices, which exhibited the best electrochemical properties. This study demonstrated that the naturally polluted GAs can be used as a reusable silica source for the synthesis of supercapacitors. Furthermore, alkali etching can enhance the electrochemical performance of metal silicates and can be used to prepare electrode materials applied for high-performance supercapacitors.

Keywords: Alkali etching; Electrochemical performance; Green algaes; Metal silicates; Supercapacitor.