Preparation of an Adsorbent Based on Amidoxime and Triazole Modified Waste Cotton Fabrics through an Azide–Alkyne Click Reaction with Excellent Adsorption Performance toward Cu(II)

The disposal of large volumes of waste cotton fabrics (WCFs) from the textile industry is an important component of waste management and a huge challenge for researchers. Therefore, it would be significant to chemically reuse WCFs as useful products, such as adsorbents for heavy metal removal. Inspired by click chemistry, we propose an easy but effective approach for the preparation of amidoxime- and triazole-functionalized waste cotton fabrics (FCF-AT) to selectively remove Cu(II) ions from aqueous solutions via an azide–alkyne click reaction strategy, and the obtained material was well-characterized. Owing to the intrinsic structural features of the fiber and excellent coordination ability, FCF-AT had a fast sorption rate and high Cu(II) ions uptake. Batch adsorption experiments showed that equilibrium was achieved within 3 h with a capacity of maximum adsorption of 122.4 mg/g at pH 6.0. The sorption mechanism was revealed based on FTIR and XPS studies and was mainly attributed to the coordination between Cu(II) and the amidoxime and triazole groups. Even after the fifth regeneration cycle, FCF-AT still displayed a perfect adsorption performance. It should be noted that the method proposed in the present work solves two industrial disposal problems at the same time, which is a good approach for its comprehensive utilization in consideration of environmental and socio-economic problems.