Enhanced photocatalytic degradation of methylene blue and methyl orange by ZnO:Eu nanoparticles

Abstract

ZnO nanoparticles doped with different Eu 3+ percentages were synthesized in water (ZnO:Eu(x%)-W) and other solvents (methanol ZnO:Eu(x%)-M and ethanol ZnO:Eu(x%)-E). X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), optical absorption and photoluminescence (PL) spectroscopy were used for characterization of the nanoparticles. Our results showed influence of europium doping and solvents on size, particles agglomeration, light absorption and photocatalytic activity. Improvement in photocatalytical activity with addition of Eu 3+ doping was detected. Particle size increased with Eu 3+ doping in water samples, while it decreased in methanol. Agglomeration was more prominent in ZnO:Eu(x)-W samples.Greater amount of surface OH groups in case of ZnO:Eu(x%)-M samples was detected by PL, XPS and FTIR measurements. Influence of europium doping, as an electron trap, and surface OH groups, as a hole trap, was studied in sunlight photocatalytic degradation of cationic methylene blue (MB) and anionic methyl orange (MO). Improved photocatalytic behavior was discussed and influence of active species was further investigated using hole and hydroxyle radical scavengers. The degradation pathway of MB and MO, using high performance liquid chromatohraphy (HPLC), is also examined.

Photocatalytic properties of zirconium oxide–zinc oxide nanoparticles synthesised using microwave irradiation

“…They confirmed higher MB removal compared to MO. They also confirmed the significant effect of the presence of OH groups during the removal of MB, while for MO, the most important factor was the formation of holes (Trandafilović et al 2017). Beura and Thangadurai studied the degradation efficiency of the Sn-ZnO-graphene for mixed dyes (MO and MB).…”

Borax-Cross-Linked Guar Gum-Manganese Dioxide Composites for Oxidative Decolorization of Methylene Blue

“…Metal oxide nanoparticles (NPs) such as titanium dioxide (TiO 2 ) [18,27], zinc oxide (ZnO) [28], nickel oxide (NiO) [29], cerium dioxide (CeO 2 ) [30], copper oxide (CuO) [30,31], and manganese oxides (MnO x ) [32] have been widely studied in oxidation processes. Among those, MnO x NPs have attracted special attention for the removal of organic dyes due to their unique structure and physicochemical properties [32,33].…”

Integration of Lanthanide–Transition‐Metal Clusters onto CdS Surfaces for Photocatalytic Hydrogen Evolution

“…Before irradiation, the Eu 52 Ni 56− x Cd x /CdS‐3 gave an intense signal at 1.922, which was attributed to the paramagnetic defect of CdS (Figure a) . An EPR signal with g of 2.003 was observed upon 30 min of irradiation, which is assigned to the paramagnetic Eu 2+ species . These results revealed that the photoinduced electron of CdS can transfer from conduction‐band of CdS to Eu 3+ , resulting in reduced Eu 2+ (Figure a).…”