Eco-conscious ZnO–cellulose composite extracted from wheat straw for photocatalytic and adsorptive applications in industrial wastewater treatment

After the harvest of wheat, the leftover wheat straw (parali) is often burned, leading to significant environmental pollution. In this study, we repurposed the leftover wheat straw into zinc oxide modified cellulose, creating an eco-friendly material with photocatalytic and adsorptive properties for wastewater remediation. The fabrication of zinc oxide-cellulose composites was achieved through a sol-gel method utilize ZnO sol and cellulose fibers, segregated from wheat straw. The produced ZnO-cellulose composites, ZnO and Celluloe were characterized utilizing FT-IR, SEM-EDX, TGA and XRD analyses. The analysis demonstrated a consistent and uniform distribution of ZnO nanoparticles on the cellulose fiber surface. A comparative study was carried out to evaluate the performance between ZnO–cellulose composites, ZnO, and cellulose, against the removal of dyes and heavy metal ions. The photocatalytic degradation of dyes demonstrated significant activity of ZnO–cellulose composites, achieving 99.69% (MB) and 38.14% (MO) dye removal within 140 min under solar irradiation. Moreover, the ZnO-cellulose composites exhibited adsorption capacities of 45.970 mg/g (91.95%) for Pb²⁺, 45.12 mg/g (90.25%) for Cd²⁺, and 38.71 mg/g (77.41%) for Cr³⁺ ions. These results emphasize the improved photocatalytic and adsorption performance of ZnO–cellulose composites compared to ZnO and cellulose, suggesting strong potential for removing organic contaminants and hazardous metal ions from wastewater.