A Copper Composite Embedded in Graphene Oxide as an Efficient Mordant to Enhance the Properties of Natural Dyes for Cotton Fabric

Synthetic dyes used in the textile sector have adverse impacts on the environment and human health. Natural dyes are thus a suitable alternative for sustainable textile manufacturing and colouration; however, preparing highly stable dyes on textile fabric remains challenging. In this study, we prepared a copper and 2-methyl-8-hydroxyquinoline (2-Me-8-HQ) functionalized graphene oxide (GO) (CHG) ternary composite as the mordant to enhance the stability and colour strength of naturally extracted turmeric (Tu) and tea (Te) dyes. To evaluate the effect of the CHG composite, it was mixed with Tu and Te dyes to obtain CHG-functionalized turmeric and tea dyes (TuCHG and TeCHG), respectively. TuCHG and TeCHG exhibited superior colourfastness, wash fastness, and rub fastness, compared with only Tu and Te dyed cotton fabrics. The cytotoxicity of TuCHG and TeCHG was studied in the presence of human keratinocytes HacaT cells. The TuCHG and TeCHG dyes exhibited no cytotoxicity and good antibacterial properties. The proposed method is safe, cost-effective, and sustainable for applying natural dyes with enhanced stability on cotton fabrics.