Photocatalytic Performance of g-C3N4 for Organic Peroxide Production Wastewater Under Visible Light

To explore the treatment-efficient photocatalytic system for organic peroxide production wastewater under visible light, the g-C3N4 catalyst, synthesized via thermal polycondensation, exhibited distinct optical absorption properties confirmed by UV-vis diffuse reflectance spectroscopy (UV–vis DRS). Operational parameters—specifically pH, catalyst loading, light intensity, and reaction time—were systematically optimized. Under optimal conditions (pH 5, g-C3N4 dosage 1.0 g/L, light intensity 1300 W/m2, reaction time 4 h), the system removed 72.8% of the COD, significantly enhancing the wastewater biodegradability (B/C ratio increased from 0.118 to 0.193). Analytical techniques, including gas chromatography–mass spectrometry (GC-MS) and UV-vis absorption spectroscopy, verified the effective decomposition of organic contaminants. Furthermore, radical quenching assays identified superoxide radicals (·O2−) and photogenerated electrons (e−) as the primary reactive species driving the photocatalytic process, highlighting the potential of g-C3N4 for industrial wastewater pretreatment.