Photodegradation of Wastewater Containing Organic Dyes Using Modified G-C₃N₄-Doped ZrO₂ Nanostructures: Towards Safe Water for Human Beings

Historically, the photocatalytic efficacy of graphitic carbon nitride (g-C₃N₄) has been constrained by a rapid charge recombination rate and restricted sensitivity to visible light. To overcome these limitations and enhance the performance of g-C₃N₄, the strategic formation of heterojunctions with semiconductor materials is deemed the optimal approach. The present study employed a facile sonication-assisted pyrolysis method to synthesize a g-C₃N₄@ZrO₂ nanocomposite photocatalyst. This hybrid material was characterized extensively using a comprehensive suite of analytical techniques, including XRD, SEM, EDX, FTIR, and UV-Vis DRS. A comparative analysis of photocatalytic applications under identical conditions was conducted for all synthesized materials, wherein they were subjected to UVc light irradiation. The photocatalytic degradation of various dye models, such as MB, EY, and a combination of dyes, was assessed using the prepared nanocomposites. The g-C₃N4@ZrO₂ photocatalysts showcased superior photocatalytic performance, with a particular variant, g-CNZ₆, exhibiting remarkable activity. With a bandgap energy of 2.57 eV, g-CNZ₆ achieved impressive degradation efficiencies of 96.5% for MB and 95.6% for EY within 40 min. Following previous studies, the superoxide radical anions (O₂⁻. and h⁺) were largely accountable for the degradation of MB. Therefore, the observed efficacy of the g-C₃N4@ZrO₂ nanocomposite photocatalyst can be attributed to the increased generation of these reactive species.