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.
