Eradication of Gram-negative bacteria by reusable carbon nitride-coated cotton under visible light

•GCN-T immobilised on cotton fabrics (CO) by an exhaustion method.•Functionalised cotton completely degraded RhB upon 60 min of irradiation.•CO/GCN-T displays antimicrobial efficiency against P. aeruginosa and E. coli.•CO/GCN-T did not affect commensal skin bacteria Staphylococcus spp.•CO/GCN-T is non-cytotoxic to skin cell lines (L929 fibroblasts and HaCaT keratinocytes).