Fabrication and photocatalytic evaluation of Cr-doped-ZnO/S-g-C₃N₄ nanocomposite: exploiting the synergistic effect for efficient environmental remediation

In this study, an effective Cr-ZnO/SGCN photocatalytic composite has been successfully fabricated by coupling chromium-doped zinc oxide nanoparticles (Cr–ZnO NPs) with sulphur-doped graphitic carbon nitride (SGCN) hydrothermally. The effect of various NP and ternary NC compositions on photocatalytic properties was also examined. Using SEM, XRD, EDX and FTIR methods, the samples' morphological, structural, and bonding characteristics were examined while band gaps were determined by employing the tauc plot methodology. Photodegradation of a model contaminant i.e., methylene blue (MB) dye, under sunlight irradiation, was brought into action for determining the photocatalytic capacity of synthetic materials. In order to identify the photocatalyst with the highest photocatalytic efficiency, a two-phase photocatalytic degradation study of (1, 3, 5, 7 & 9) wt.% Cr–ZnO NPs and Cr–ZO/(5, 10, 15 and 20 wt.%) SGCN NCs was conducted against MB. The 5% Cr–ZnO NPs and 5% Cr–ZnO/20% SGCN NCs presented the best optical absorption and photocatalyst effectiveness in stages one and two, respectively. Observed improved photocatalytic performance of Cr–ZnO/20% SGCN NC can be accredited to e–h pair separation and better absorption between SGCN and Cr–ZnO. As a result, the intended study provides good insight for creating a suitable visible-light-driven photocatalyst having useful environmental remediation applications.