<p>The growing environmental challenges caused by dye pollutants in wastewater highlight the urgent need for more practical and sustainable treatment methods. This review presents an overview of recent progress in wastewater purification, with particular attention to photocatalysis and other energy-efficient approaches. The concept and mechanisms of advanced oxidation processes (AOPs) are briefly discussed, followed by an assessment of different AOP techniques and their effectiveness in degrading dye contaminants. A significant focus is placed on coupling photocatalysis with energy conversion technologies, such as photoelectrochemical (PEC) and microbial fuel cells (MFC), which can achieve dye degradation while also generating clean energy. A comparative discussion of various photocatalytic systems is included, emphasizing their efficiency, limitations, and scale-up potential for dye removal and hydrogen generation. The synthesis, characterization, and modification of photocatalysts are also outlined to provide practical insight into their performance. Finally, the review summarizes existing challenges such as low catalyst efficiency, high cost, and limited scalability and offers possible directions for improving wastewater treatment and energy recovery. Overall, the work highlights how integrating environmental remediation with renewable energy conversion can contribute to sustainable wastewater management.</p>