This study presents a solar-matched S-scheme ZnO/g-C₃N₄ photocatalyst for efficient visible light-driven degradation of paracetamol in wastewater. The composite was synthesized using hydrothermal and calcination methods, with varying concentrations of g-C₃N₄ (3, 5, 10, and 20 wt%) in ZnO. The optimized composite with 10 wt% g-C₃N₄ showed the highest degradation efficiency of 95% within 60 minutes under visible light, a 2.24-fold increase compared to lower concentrations. The enhanced performance was attributed to band gap narrowing matching solar radiation, efficient charge transfer via S-scheme heterojunctions, and increased surface area. Scavenging experiments identified hydroxyl radicals as the primary reactive species. The composite exhibited excellent photostability and reusability, making it suitable for practical applications. The study highlights the importance of band alignment and charge carrier separation in photocatalytic efficiency. The results demonstrate the potential of ZnO/g-C₃N₄ as an effective and sustainable photocatalyst for removing pharmaceutical pollutants from aquatic environments.This study presents a solar-matched S-scheme ZnO/g-C₃N₄ photocatalyst for efficient visible light-driven degradation of paracetamol in wastewater. The composite was synthesized using hydrothermal and calcination methods, with varying concentrations of g-C₃N₄ (3, 5, 10, and 20 wt%) in ZnO. The optimized composite with 10 wt% g-C₃N₄ showed the highest degradation efficiency of 95% within 60 minutes under visible light, a 2.24-fold increase compared to lower concentrations. The enhanced performance was attributed to band gap narrowing matching solar radiation, efficient charge transfer via S-scheme heterojunctions, and increased surface area. Scavenging experiments identified hydroxyl radicals as the primary reactive species. The composite exhibited excellent photostability and reusability, making it suitable for practical applications. The study highlights the importance of band alignment and charge carrier separation in photocatalytic efficiency. The results demonstrate the potential of ZnO/g-C₃N₄ as an effective and sustainable photocatalyst for removing pharmaceutical pollutants from aquatic environments.