Boosting solar-driven photocatalytic degradation of organic contaminants and bacterial deactivation using marigold- like Cu2O decorated g-C3N4 nanocomposite

Abstract

Keeping the high efficiency in designing photocatalysts in view, the present work was aimed at the development of a heterojunction photocatalyst with boosted efficiencies, both for degradation of organic contaminants and bacterial deactivation. Heterojunction nanocomposites of g-C3N4 (GCN) and Cu2O (Cu2O /GCN-5 %, Cu2O /GCN-15 %, Cu2O/GCN-25 %, and Cu2O /GCN-50 %) were prepared by hydrothermal method and their photocatalytic performance was evaluated. XPS result confirms the surface chemical composition of nanocomposite and consistent with EDX analysis. The BET studies of Cu2O/GCN −25 % nanocomposite reveals the larger specific surface area (128.10 m2/g), compared to intact Cu2O, which facilitates more active sites on the surface. The optical bandgap energy (2.39 eV-2.58 eV) is tuned towards the visible region by loading g-C3N4 in marigold-like Cu2O. The efficient charge transfer betwixt marigold-like Cu2O and g-C3N4 was demonstrated in PL, CV, and EIS analysis. The Cu2O/GCN-25 % nanocomposite exhibits superior photocatalytic activity towards Aniline blue dye (86.4 %) and β-lactam antibiotic amoxicillin (79 %) under 100 min of sunlight irradiation. HPLC analysis further confirmed the degradation and disintegration of Amoxicillin. The probable photocatalytic mechanism was proposed and tested through a radical scavenger experiment. It was found that ●OH radicals significantly take part in the photodegradation. In addition, the bactericidal activities of Cu2O/GCN-25 % nanocomposite was determined. The highest bactericidal activity was observed for Bacillus subtilis (26 mm). Hence, the marigold-like Cu2O/GCN-25 % nanocomposite is a feasible material for the degradation of dyeing and pharmaceutical industrial effluents as well as bacterial growth inhibition.