To read the full version of this content please select one of the options below:

Electrochemical reduction of indigo by combination of sodium borohydride and copper salt

Xiaoyan Li (College of Textile and Garment, Hebei University of Science and Technology, The Innovation Center of Textile and Garment Technology, Hebei, China)
MengQian Wang (College of Textile and Garment, Hebei University of Science and Technology, The Innovation Center of Textile and Garment Technology, Hebei, China)
Gang Wu (College of Textile and Garment, Hebei University of Science and Technology, The Innovation Center of Textile and Garment Technology, Hebei, China)
Jiming Yao (College of Textile and Garment, Hebei University of Science and Technology, The Innovation Center of Textile and Garment Technology, Hebei, China)

Pigment & Resin Technology

ISSN: 0369-9420

Article publication date: 8 December 2020

Issue publication date: 11 May 2021

87

Abstract

Purpose

The purpose of this study is to improve the performance of sodium borohydride in reducing indigo at room temperature, the divalent copper ion complex was combined with electrochemical technology for the reduction of indigo by sodium borohydride.

Design/methodology/approach

According to the K/S value of the dyed cloth sample, find a more suitable ligand for the copper ion in the catholyte. Response surface analysis tests were performed to evaluate the effects of sodium borohydride concentration, sodium hydroxide concentration and copper sulfate pentahydrate concentration on the reduction potential of the dye solution and the K/S value of the dyed fabric samples.

Findings

Sodium gluconate was found to be a more suitable ligand for copper ions in catholyte. The effects of NaOH concentration as well as the interaction of NaBH4 and NaOH on the reduction potential of the catholyte and the K/S value of the dyed fabric samples were extremely significant. The optimal concentrations of NaBH4, NaOH and CuSO4•5H2O were 0.5, 2.5 and 0.65 g/L. In the case of the optimized condition, the absolute value of the reduction potential was 968, and the K/S value was 11.92, which is comparable with that of the conventional reduction process with sodium dithionite.

Originality/value

The divalent copper ion complex combined with electrochemical technology was applied in the process of reducing indigo with NaBH4 at room temperature.

Keywords

Acknowledgements

This research was supported by Natural Science Foundation for Young Scientists of Hebei Province (Grant No. E2019208319), Scientific Research Project of Colleges for Young Scientists in Hebei Province (QN2020235) and National Innovation and Entrepreneurship Training Program for College Students (201910082012).

Citation

Li, X., Wang, M., Wu, G. and Yao, J. (2021), "Electrochemical reduction of indigo by combination of sodium borohydride and copper salt", Pigment & Resin Technology, Vol. 50 No. 3, pp. 185-193. https://doi.org/10.1108/PRT-04-2020-0035

Publisher

:

Emerald Publishing Limited

Copyright © 2020, Emerald Publishing Limited

Related articles