Synthesis and characterization of gadolinium tungstate integrated with pineapple leaf biomass hybrid

• Gd 2 (WO 4 ) 3 /PL hybrid synthesized via hydrothermal-biomass route • Band gap tuned from 2.53 to 1.93 eV enabling visible-light range activity • Nanocomposite shows suppressed e - -h + recombination for improved performance • PL biomass introduced a porous structure for a better adsorption of pollutants • Crystal, optical, and morphological synergy yields a superior structure. Water contamination by co-existing organic pollutants and heavy metals remains a critical challenge for sustainable wastewater treatment. This study reports the hydrothermal synthesis and physicochemical characterization of a hybrid nanocomposite consisting of gadolinium tungstate (Gd 2 (WO 4 ) 3 ) integrated with pineapple leaf biomass, designed as integrated photocatalyst-adsorbent material. X-ray diffraction and Rietveld refinement confirmed the monoclinic crystal structure with dimensions in the nanoscale range. TEM/SEM analysis revealed morphology transformation from cubic WO 3 to closely dense agglomerated nanoparticle for Gd 2 (WO 4 ) 3 , and a porous heterogeneous sponge like texture for Gd 2 (WO 4 ) 3 /pineapple leaf biomass hybrid. SAED patterns also validated crystallinity strongly corresponding to XRD reflections, whereas FTIR spectra confirmed the presence of W-O, O-W-O, and Gd-W metal bonds. Optical analysis demonstrated a systematic band gap reduction from 2.20 eV (Gd 2 (WO 4 ) 3 ) to 1.93 eV for the hybrid composite, accompanied by suppressed photoluminescence intensity, indicating improved charge carrier separation. The incorporation of pineapple leaf biomass introduced structural heterogeneity and interfacial interactions that improved light absorption and electronic properties. These findings demonstrate that biomass- supported gadolinium tungstate nanocomposite offer a structurally stable and optically tuneable platform with strong potential for integrated adsorption-photocatalytic wastewater treatment applications.