Synthesis and enhanced catalytic performance of CdTe/ZnS heterostructured nanocomposites for organic dye reduction

¹ Department of Chemistry, Gandhi Institute of Engineering and Technology University, Gunupur, 765022, Odisha, India
² Department of Chemical Engineering, SOET, Gandhi Institute of Engineering and Technology University, Gunupur, 765022, Odisha, India
³ Department of Engineering Chemistry, SRKR Engineering College, Bhimavaram, 534204, Andhra Pradesh, India
⁴ Department of Chemical and Biochemical Engineering, IIT Patna, 801106, India

^* Corresponding author: diwakar.b@srkrec.edu.in

Published online: 7 January 2026

Abstract

The successful synthesis and thorough characterization of CdTe/ZnS nanocomposites using the solvothermal method are presented in this work, along with their use as effective and sustainable catalysts for the degradation of organic dyes. UV-Vis spectroscopy is used to analyze the formation of developed materials. The successful engineering of optical properties through nanocomposite formation is demonstrated by the systematic variation in band gap energies from CdTe (1.94 eV) through the composite (2.28 eV) to ZnS (3.63 eV). The formation of sphalerite ZnS and cubic zinc blende CdTe phases with an average crystallite size of about 30 nm was verified by X-ray diffraction analysis. Spherical nanoparticles with sizes between 20 and 80 nm were found using scanning electron microscopy. Congo Red and Rhodamine-B dyes were used to assess the catalytic performance in the presence of NaBH4 using pseudo-first-order kinetics. With rate constants of 0.02923 min⁻¹ for Congo Red and 0.04902 min⁻¹ for Rhodamine-B, the CdTe/ZnS nanocomposite outperformed individual CdTe and ZnS nanoparticles in terms of catalytic activity. The enhanced performance is attributed to synergistic electron-hole separation at the CdTe/ZnS interface. The reusability of the nanocatalytsts revealed that the efficency is withstand for the next three cycles without a noticeable change in morphology. This type of heterostructures represents a promising nanomaterial for environmental remediation applications in efficient organic pollutant removal.