Effect of Chitosan loading towards structural, optoelectronic and photocatalytic degradation of flakes like CuO-Chitosan nanocomposite

The development of a stable and extremely active photocatalyst has attracted substantial consideration in the area of wastewater treatment and photoelectrocatalytic (PEC) water splitting. In recent work, flakes-like CuO–chitosan nanocomposites were effectively synthesized to investigate the impact of chitosan loading on their structural, photocatalytic degradation of Methylene blue (MB) and optoelectronic characteristics. The CuO–chitosan nanocomposites were prepared via a simple co-precipitation route by varying chitosan contents (0.1 g (CCu1), 0.3 g (CCu3), and 0.5 g (CCu5)). FTIR and X-ray diffraction (XRD) confirmed the structural studies like monoclinic phase of CuO, its smaller crystallite size was observed with increased chitosan concentration. SEM/EDX analyses revealed a flakes-like morphology and composition with enhanced surface uniformity and reduced agglomeration upon chitosan incorporation. The optical performance of CuO-Chitosan nanocomposites was assessed with UV by evaluating optical band gaps of CCu1(3.34eV), CCu3(3.32eV), and CCu5 (3.29eV), suggesting CS incorporation effectively reduce band gap of pure CuO (3.36 eV). Photocatalytic degradation investigations revealed that optimized chitosan loading significantly enhanced degradation efficiency of CCu5 which shows 93 % degradation of methylene blue (MB) within 150 min under visible light. The optoelectronic characteristics of all four samples were tested by LSV, EIS and MS plots. Among them CuC5 depicts higher current density, low charge transfer resistance and greater electron Donar density (Nd =8.4×10 ¹² cm ³ ) as compared to CuC1, CuC3 and CuO respectively. The results highlight that controlled chitosan loading effectively modify the physicochemical, photocatalytic dye degradation and optoelectronic properties of CuO, making them promising candidates for environmental remediation and photocatalytic applications.