Fabrication of Z-scheme ZnO/g-C₃N₄/ZnS nanocomposites using high power laser for methylene blue degradation

Photocatalysis plays a vital role in addressing environmental challenges by harnessing solar energy for efficient pollutant degradation. In this study, we investigate the photocatalytic activity of a ZnO/g-C₃N₄/ZnS composite system in the degradation of methylene blue, a widely used dye with detrimental effects on aquatic ecosystems. The composite materials were synthesized using a facile and scalable approach, and their structural properties, morphologies, sizes, and elemental compositions were characterized using different analytical techniques. The ZnO/g-C₃N₄/ZnS composite exhibited enhanced photocatalytic performance compared to individual components. Remarkably, the degradation efficiency reached 80% for the composite with a 30% ZnO composition, surpassing the efficiencies of ZnS alone (29%) and ZnS/g-C₃N₄ (65%). The composite’s higher degradation efficiency is due to synergistic semiconductor effects, enhancing charge transfer and reducing electron-hole recombination. ZnO incorporation increases active sites and surface area, improving interaction with methylene blue. The favorable band edge positions of ZnO aligned with ZnS and g-C₃N₄, facilitating the utilization of a broader spectrum of solar light. The composite’s photocatalytic activity was achieved under UV light irradiation, demonstrating its potential for sustainable and energy-efficient applications. This study highlights the significance of composite design and the Z-scheme concept in photocatalysis, offering insights into the development of advanced materials for environmental remediation. The findings contribute to the understanding of efficient solar-driven pollutant degradation and pave the way for the design and optimization of innovative photocatalytic systems for sustainable environmental solutions.