Fast sunlight-driven photo-adsorptive degradation of an aromatic dye using Fe3+/Sb3+ incorporated copper oxide nanocatalysts

Abstract

The existence of hazardous, dangerous and non-biodegradable aromatic organic contaminants in the environment poses great challenges to human health and ecosystems. This research studied the influence of codoping by Fe/Sb ions on the photodegradation activity of nanocrystalline CuO towards Congo red (CR) dye under solar irradiation. Nanocrystalline samples of pure, (1% Fe + 1% Sb) and (3% Fe + 3% Sb) co-doped CuO were produced via the coprecipitation method. X-ray diffraction (XRD) results confirmed the single monoclinic phase with C2/c space group for the pure, (1% Fe + 1% Sb) and (3% Fe + 3% Sb) co-doped CuO samples, with crystalline sizes within 33–58 nm. The well-known Kubelka–Munk method revealed that the band gap energies of pure, (1% Fe + 1% Sb) and (3% Fe + 3% Sb) co-doped CuO samples were 1.48, 1.5 and 1.49 eV, respectively. X-ray photoelectron analysis of Fe/Sb co-doped CuO powder verified that Cu, O, Fe and Sb constituents are in the +2, −2, +3 and +3 oxidation states, respectively. Morphological study showed that the pure CuO and (1% Fe + 1% Sb) co-doped CuO samples exhibited a regular distribution of particle size and shape, while the (1% Fe + 1% Sb) co-doped CuO particles displayed large grains with irregular morphology. For environmental remediation, photocatalytic tests revealed that the Fe/Sb co-doping considerably boosted the degradation rate of Congo red dye under solar irradiation. The (1% Fe + 1% Sb) co-doped CuO catalyst was the most effective photocatalyst, with a measured efficiency of 97% after 20 min of solar irradiation. Thus, Fe/Sb co-doping is a promising strategy for the usage of nanostructured CuO powder in wastewater treatment.