Copper Oxide (Cuo) Nanoparticles with Sulfur-Doped Graphitic Carbon Nitride (S-G-C3n4) Nano composite and its Catalytic Dye Degradation

Abstract

NC materials based on metal oxide NPs and S-g-C3N4 have gained increasing attention for their wide range of potential applications in various material science fields. In this study, CuO NPs, S-g-C3N4 and CuO/S-g-C3N4 NCs catalysts were successfully synthesized by precipitation method, direct polymerization of thiourea and liquid exfoliation methods, respectively. In the synthesis of CuO NPs, 0.15 M, and pH 8 were the optimized parameters of concentration and pH respectively. Whereas 550 oC is the optimized calcination temperature for the synthesis of S-g C3N4 and (0.25:0.5) g of CuO: S-g-C3N4 is for the synthesis of NCs. The synthesized NPs and NCs were characterized by using UV-Vis spectroscopy; XRD; SEM, and FT-IR techniques. The energy band gap information from UV-Vis characterization shows that the successive decrement values, 1.88 eV for CuO NPs, 1.82 eV for S-g-C3N4 and 1.75 eV for CuO/S-g-C3N4 NCs. The XRD characterization shows that the synthesized samples were highly crystallized. The SEM image shows spherical shape for CuO NPs, wrinkled or hole like morphology for S-g-C3N4 and the mixture of two for NCs. Results suggested that the CuO/S-g-C3N4 NCs photocatalyst exhibited a relatively higher efficiency on the photodegradation of MB than CuO NPs and S-g C3N4. The effects of operational parameters such as pH, initial dye concentration, irradiation time and photocatalyst loads were studied by CuO/S-g-C3N4 NCs. The CuO/S-g-C3N4 nanocatalyst along with water exhibited remarkable catalytic activities towards MB with a degradation efficiency of 95.1% in a short reaction time. The results indicated that high degradation efficiency (95.1%) was achieved by using 0.1 g/L of photocatalyst dose, pH of 8, 10 ppm MB aqueous solution, and irradiation time of 80 min. Stability of the as synthesized photocatalyst was tested and found to be having only about 62.3% decrement after four successive cycles due to loss of catalyst during sampling. The novel CuO/S-g-C3N4 NC is a promising catalyst for the application of catalytic degradation of MB dyes in industrial wastewater.