Synergistic Photocatalytic and Catalytic Dynamics of Microgel‐Templated and Hydrolysed Microgel‐Derived CuS Nanocomposites: Unveiling Reductive Mechanisms and Functional Enhancements

This study delineates the synergistic catalytic–photocatalytic interplay and mechanistic details of microgel‐templated and hydrolysed microgel‐derived copper sulfide (CuS) nanocomposites, emphasizing their redox behavior, interfacial charge modulation, and functional stability. Directed by green chemistry principles, CuS catalysts were rationally engineered within neutral (SAN) and hydrolysed anionic (SANH) microgel matrices to achieve sustainable performance optimization. The dual microgel framework facilitated systematic evaluation of surface charge and polarity on catalytic efficiency, electron transfer kinetics, and operational recyclability. SAN@CuS and SANH@CuS nanocomposites were synthesized via free‐radical emulsion copolymerization of styrene, acrylamide, and NHMA, followed by hydrothermal co‐precipitation of CuS nanoparticles. Comprehensive characterization (UV–Vis., FT‐IR, XRD, TGA, SEM, TEM, EDX, and DLS) confirmed homogeneous CuS encapsulation, structural coherence, and improved electronic coupling within the SANH matrix. Kinetic investigations revealed that methylene blue reduction by NaBH 4 followed pseudo‐first‐order kinetics ( k = 6.8 × 10 − 2 s − 1 ), whereas solar‐assisted photodegradation proceeded with k = 1.6 × 10 − 2 min − 1 . The hydrolysed anionic microgel demonstrated superior charge transport, photon utilization, and substrate accessibility, enhancing catalytic turnover and durability with negligible Cu leaching. Overall, the coupled CuS–microgel architecture establishes an efficient, recyclable, and environmentally benign hybrid platform for sustainable wastewater remediation and the design of next‐generation photocatalytic systems.