Textile waste as an alternative source in the production of carbon quantum dots: synthesis, characterization and multifunctional application.
Wastewater; Laundry; Textiles; Quantum Dots; Solvothermal; Antimicrobials.
Textile liquid waste (effluents) are highly polluting wastewater generated during dyeing and finishing, containing substances that are difficult to degrade, strong colors, and toxic organic/inorganic compounds. The industry consumes approximately 93 billion cubic meters of water annually, requiring rigorous treatment (physico-chemical/biological) to avoid contaminating soils and groundwater. Therefore, the main characteristics and impacts are: Composition: High load of dyes (especially azo dyes, which are difficult to degrade), heavy metals, salts, surfactants, and dispersing agents. Environmental Impact: Toxicity to aquatic ecosystems, increased chemical oxygen demand (COD), and difficult discoloration of water bodies. Volume: The textile sector consumes enormous volumes of water, generating toxic effluents that require specialized treatment. It is known that due to its large organic load, it is necessary to evaluate the potential of its application in obtaining high-value-added materials, such as carbon quantum dots. Carbon quantum dots (CQDs) are carbon nanoparticles with dimensions smaller than 10 nanometers. Accidentally discovered in 2004, they stand out for their strong photoluminescence and unique physicochemical properties, being considered a safer and more sustainable alternative to traditional semiconductor quantum dots (which generally contain toxic heavy metals). In this work, carbon quantum dots in different colors and sizes were obtained via solvothermal synthesis. The method of obtaining them was previously optimized and characterized via HRTEM, E. Photoluminescence, XPS, TG/DSC, as well as colorimetric analyses. Thus, the potential of a rich residue from the textile industry as a direct source for obtaining quantum dots in sizes between 2 nm and 6 nm, in green, red, and blue colors, with high antimicrobial activity and potential application in textile fibers, was proven.