Structural, photoluminescence, and photocatalytic properties of Mn and Eu co-doped ZnO nanoparticles

The solar driven-photocatalytic degradation using semiconductor nanoparticles (NPs) is an efficient approach to make wastewater free from organic pollutants. In this aspect, pristine ZnO NPs, Mn-doped ZnO NPs (Mn-ZnO NPs), and Mn, Eu co-doped ZnO nanoparticles (Mn-Eu-ZnO NPs) were synthesized by a soft chemical approach. XRD analysis confirmed the formation of a single-phase wurtzite structure without any additional phase impurity. TEM micrograph of Mn-Eu-ZnO NPs indicated the formation of spherical particles of size in the range of 8–15 nm. The photoluminescence spectra of Mn-Eu-ZnO NPs showed a broad defect band in the range of 400 to 750 nm suggesting its higher defect concentration as compared to ZnO NPs and Mn-ZnO NPs. The doped ZnO NPs exhibited higher photocatalytic degradation of Rhodamine B (RhB) under simulated solar light. Mn-Eu-ZnO, Mn-ZnO, and ZnO NPs showed complete photodegradation of RhB in 20, 40, and 90 min under simulated solar light, respectively. The enhanced photocatalytic degradation activity of Mn-Eu-ZnO NPs can be ascribed to the presence of higher defect concentration, enhanced optical absorption ability, high charge separation efficiency, and reduction in the recombination of photogenerated electron-hole pairs as well as their strong affinity for hydroxyl radical generation. Thus, the developed Mn-Eu-ZnO NPs can be used as potential photocatalyst for the degradation of organic dyes from wastewater.