Solar Photocatalytic Mineralization of Dye New Coccine in Aqueous Phase Using Different Photocatalysts

The objective of this study was to examine the effect of band gap of photocatalyst on the decolorization of dye new coccine (NC). The concentration of NC in the present of CuO, Fe2O3, TiO2, and ZnO reduced to 50.5, 23.3, 0.1, and 0 mg L−1, respectively, after 5 h solar light irradiation. The concentration of NC in dark condition only decreased to 48.140, 45.079, 35.269, and 31.045 mg L−1 with CuO, Fe2O3, TiO2, and ZnO as photocatalysts, respectively, after 5 h contact time. The absorbance peaks and chemical oxygen demand (COD) concentration of NC in the presence of TiO2 and ZnO decreased to baseline and zero compared to the CuO and Fe2O3. The COD concentration of NC with CuO, Fe2O3, TiO2, and ZnO as photocatalysts reduced to 21, 13, 0, and 0 mg L−1, respectively, after 12 h of solar irradiation. The surface morphology of photocatalysts was examined by scanning electron microscope (SEM), and it was found that the particle size of CuO, Fe2O3, TiO2, and ZnO ranging 250–375, 250–600, 40–100, and 60–500 nm, respectively. In summary, the higher band gap energy level indicated greater photocatalytic degradation and mineralization of NC.