Facile synthesis of MnO₂/g-C₃N₄ for photocatalytic reduction of methylene blue dye under visible light

Water pollution has recently come to the forefront of people’s minds because of the widespread textile dye contamination. It suffers from a wide variety of harmful chemicals in the textile, cosmetics, food, and paint industries and these are removed by photocatalysis. Photocatalytic degradation is considered an efficient approach for the elimination of toxic pollutants from industrial effluents. In this work, MnO₂/g-C₃N₄ nanocomposite was developed hydrothermally for photocatalytic mineralization of methylene blue (MB) dye. The surface study revealed that MnO₂/g-C₃N₄ shows a greater surface area (97 m² g⁻¹) attributed to the g-CN nanosheet. The photocatalytic efficiency of MnO₂, g-C₃N₄ & MnO₂/g-C₃N₄ materials was additionally ascertained via the degradation of MB, which was considered to be a model dye. The MnO₂, g-C₃N₄ & MnO₂/g-C₃N₄ display the photocatalytic efficiency of 72.34, 85.81, and 94.32%, respectively. According to the TOC study, the MnO2/g-C3N4 nanocomposite showed a degradation rate of 71.23% over a period of 150 min. The scavenger analysis revealed that charge species (hydroxyl, hole and superoxide anion) play a substantial part in the photodegradation of dyes. The results show that the fabricated nanocomposite shows maximum photocatalytic efficacy compared to pristine material due to the appropriate bandgap along with unique structural features. The developed catalyst not only has the potential to degrade the dye and it can also work in other energy storage applications.