<p>Environmental contamination from industrial and agricultural activities has seriously threatened ecosystems and human health. Semiconductor-based photocatalyst nanomaterials present a promising solution for mitigating ecological pollution due to their ability to harness solar energy for the efficient degradation of organic pollutants and other toxic substances. This review highlights recent advancements in the synthesis, properties, and applications of semiconductor photocatalysts. Special emphasis is placed on the role of nanoscale materials, including their optical, electronic, and magnetic properties, which make them uniquely suited for photocatalytic and sonocatalytic applications. Integrating various strategies, such as morphological control, heterostructure formation, and green synthesis protocols, is discussed to enhance photocatalytic efficiency and address challenges such as limited visible light activity and high electron-hole recombination rates. This comprehensive review also explores diverse applications ranging from water purification to renewable energy production, illustrating the transformative potential of these nanomaterials in creating sustainable and eco-friendly solutions.</p> Graphical Abstract <p></p>