Environmentally Friendly g-C3N4/Sepiolite Fiber for Enhanced Degradation of Dye under Visible Light

Herein, novel visible light active graphitic carbon nitride (g-C3N4)/sepiolite fiber (CN/SS) composites were fabricated via a facile calcination route, exploiting melamine and thiourea as precursors, and sepiolite fiber as support, for efficient degradation of organic dye methylene blue (MB). The as-prepared CN/SS composites were characterized by various characterization techniques based on structural and microstructural analyses. The effects of CN loading amount, catalyst dosage and initial concentration of dye on the removal rate of dye under visible light were systematically studied. The removal rate of MB was as high as 99.5%, 99.6% and 99.6% over the composites when the CN loading amount, catalyst dosage and initial concentration of dye were 20% (mass percent), 0.1 g, and 15 mg/L in 120 min, respectively. The active species scavenging experiments and electron paramagnetic resonance (EPR) measurement indicated that the holes (h+), hydroxyl radical (·OH) and superoxide radicals (·O2−) were the main active species. This study provides for the design of low-cost, environmentally friendly and highly efficient catalysts for the removal of organic dye.