Photochemical Construction of P(St-AM)-Based Cu Species Composite Microspheres for Dye Adsorption

P(St-AM)-based Cu species (Cu, Cu₂O, CuO) composite microspheres have been successfully prepared by a photochemical construction technology at room temperature. The process involved the photochemical synthesis of P(St-AM) microspheres and the following deposition of Cu species nanoparticles on the surface of P(St-AM) microspheres under the irradiation of 365 nm and 254 nm UV lamps, respectively. The as-obtained composite microspheres were characterized by SEM, XRD, FTIR, DSC, and BET analyses. The as-prepared P(St-AM)-Cu-1 which has the minimum loading amount of Cu species nanoparticles was chosen as the typical adsorbent, and methyl orange was selected as a representative dye containing sulfonic groups. The adsorption capacity reached a maximum of 125.5 mg g^-1 at methyl orange concentration of 276.0 mg L^-1. The pseudo-second order kinetic model and Langmuir isotherm model described the adsorption behavior. The higher correlation coefficient (R²) and smaller values of error functions (χ², root-mean-square error) validated applicability of both the models. The composite microspheres demonstrated excellent cyclic stability. This work presents a promising photochemical strategy for constructing polymer-metal composite adsorbents for dye adsorption.