Thermal studies of Mn2+-doped ZnO powders formation by sol–gel method

Reduction of hazardous reactive oxygen species (ROS) production of ZnO through Mn inclusion for possible UV-radiation shielding application

“…As an agreement to the XRD data, a wurtzite ZnO characteristic Raman peak was observed at 436 cm À1 for the pristine ZnO. This peak is ascribed as the E 2H high phonon mode [25,39]. An additional band, the 3E 2L was observed at 330 cm À1 also for the pristine ZnO.…”

“…The values of D from this method were denoted as D W-H and the obtained values (Table 1) were found to correlate well with those calculated from Scherer method (D D-S ). The reduction in crystallite size upon Mn 2þ doping has been reported in literature and attributed to the generation of a retarding force on the grain boundaries that exceeds the driving force for grain growth of Zn, thus impeding the movement of the grain boundary and resulting in moderate reduction of the crystallite size as the dopant concentration is increased [25,30].…”

“…Both the E 2H and 3E 2L peaks were slightly shifted towards lower frequencies for the Mn-doped ZnO. Vladut et al (2018) [25] and Das et al (2015) [40] also reported some peak shifting when doping ZnO with Mn ions, which they said was an indication of tensile stress induced in the crystal. Ahmed and co-authors [26], further highlighted that impregnating transition metals in the ZnO lattice leads to microscopic topological and structural disorders in the periodic Zn atomic sub lattice and breaks translational symmetry.…”

“…According to Tsuzuki [24], contradictory results may be attributed to location of dopants as well influence from the fabrication method. Recently, Mn has been incorporated on ZnO to tailor its physiochemical properties including thermal [25], magnetic [26,27], optical [28,29] and piezoelectric properties [30]. However, limited progress has been made on deliberate addition of Mn ions to ZnO to suppress its photocatalytic activity for safe UV shielding applications.…”

The Influence of Gel Preparation and Thermal Treatment on the Optical Properties of SiO2-ZnO Powders Obtained by Sol–Gel Method

“…The FTIR spectra for treated powders are shown in Figure 3 . The bands that are typical of Si-O vibrations are visible in the recorded spectra and are identical to those that have been described in the literature [ 16 , 17 , 18 , 19 , 20 , 21 ]. Small bands at 560 cm −1 or 568 cm −1 may be attributed to the vibration of the Si-O-Zn bonds, whereas the main bands at 1273 cm −1 , 1080 cm −1 , 1114 cm −1 , 793 cm −1 , and 467 cm −1 are assigned to Si-O-Si bonds in networks and chains.…”