UV‐A Induced Photocatalytic Degradation of Acid Green 16 Using La 2 WO 6 /ZnO Heterojunction Nanocomposites: Synthesis and Biological Applications

ABSTRACT Increasing concerns related to dye‐contaminated wastewater and the demand for multifunctional materials have prompted studies on semiconductor‐based nanocomposites for environmental and biological applications. In this context, a 7 wt.% La 2 WO 6 /ZnO nanocomposite was synthesized via a hydrothermal method and examined for its structural, optical, photocatalytic, and biological characteristics. SEM analysis showed the coexistence of smaller ZnO particles and comparatively larger La 2 WO 6 particles within the same microstructure. XRD confirmed crystalline hexagonal ZnO and monoclinic La 2 WO 6 phases without detectable structural alteration. UV–DRS measurements showed band gap values of 3.2 eV for ZnO, 2.8 eV for La 2 WO 6 , and 2.6 eV for the composite. Photocatalytic performance was evaluated through the degradation of the anionic azo dye Acid Green 16 (AG‐16) under UV light irradiation. The influence of solution pH, initial dye concentration, and catalyst dosage on degradation efficiency was systematically investigated, and the catalyst was reused for five successive cycles under identical experimental conditions to assess its stability. Antibacterial activity was assessed using the agar well diffusion method, and cytotoxicity was evaluated against MCF‐7 breast cancer cells. The results demonstrate the structural features and functional performance of the La 2 WO 6 /ZnO nanocomposite in AG‐16 degradation, along with its biological activity under the studied conditions.