TGA-capped CdTe/ZnSe nanoparticles for efficient sunlight-driven pollutant removal: Synthesis, photophysical characterization, and statistical physics approach of photodegradation

Water-soluble thioglycolic acid (TGA)-capped CdTe/ZnSe core–shell nanoparticles were synthesized under mild aqueous conditions and characterized by XRD, XPS, TEM, PL, and UV–Vis analyses. The 2–3 nm nanocrystals showed a distinct blue shift in optical spectra, confirming quantum confinement. Their dual functionality in adsorption and photocatalysis was assessed for methylene blue (MB) removal under sunlight. Under optimal conditions (pH 7, 10 mg/L MB, 30 mg catalyst), a degradation efficiency of 95.9 % was achieved in 180 min. Adsorption data fit the Langmuir–Freundlich model, with a maximum capacity of 49.6 mg/g, indicating spontaneous and exothermic interactions. Statistical physics modeling clarified the energetic and steric aspects of dye–surface interactions as monolayer physisorption driven by hydrogen bonding and van der Waals forces. Overall, CdTe/ZnSe–TGA nanostructures exhibit excellent stability and strong potential as sunlight-driven, dual-function materials for sustainable wastewater purification.