Alginate reinforced composite of CuO-gC3N4: Synthesis, characterization and photocatalytic activity

•Developed CuO-gC3N4 based hydrogel photocatalyst by ionotropic gelation method.•The incorporation of CuO-gC3N4 in Alginate tuned the bandgap of the resultant material.•The prepared photocatalyst exhibit good degradation ability with reusable characteristics. In this work, we report the fabrication of a novel and reusable CuO-gC3N4 based photocatalyst. The Alg/CuO-gC3N4 was prepared by two step process; first CuO-gC3N4 was synthesized by co-precipitation method, followed by its incorporation in the calcium alginate (Alg) through a facile ionotropic gelation method. The resultant material was characterized using appropriate techniques, including Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV Diffuse Reflectance Spectroscopy (UV-DRS). The photocatalytic activity of the CuO-gC3N4 and Alg/CuO-gC3N4 were assessed to degrade tetracycline (TC) under UV–vis irradiation. This research presents a promising avenue for the design of biocompatible and cost-effective materials for environmental remediation applications.