Synthesis, characterization, and performance evaluation of pristine and cerium‐doped WO₃ nanoparticles for photodegradation of methylene blue via solar irradiation

Abstract

In this study, an effective photodegrading properties of WO3 nanoparticles has been enhanced by doping with cerium. To achieve our goal pristine and Ce‐doped WO3 nanoparticles were prepared by a simple and cost effective co‐precipitation route. Characterization of all the specimens were conducted which showed that there were no noticeable structural changes. WO3 retained its monoclinic structure even after doping with (3%, 5%, 8%, 10%) cerium which was also confirmed with X‐ray diffraction (XRD) and Raman spectroscopy. In addition, XRD and Fourier transform infra‐red spectroscopy also confirm that no new phases were formed in doped specimens. XRD also depicts that minimum crystallite size is achieved at 3% cerium doping. Scanning electron microscope images show decrease in particle size initially at 3% cerium doping, that is, ~80 ± 2.5 nm. In contrast, further increase in doping percentage increases crystallite and particle sizes. Additionally, defect generation increased at lower doping percentage ~3%. In contrast, further increase in dopant (5%, 8%, 10%) caused defect annihilation process to dominate over defect generation. C/Co ratio and rate constant (KMB) values suggest that maximum degradation of methylene blue will occur at 3% cerium doping due to increase in crystalline defects. Ultraviolet visible Spectroscopy further validates C/Co ratio and degradation rate constant values by showing drastic decline in peak intensity at 3% cerium doping. Therefore, 3% cerium‐doped WO3 is more effective photocatalyst to degrade methylene blue in comparison to most of the previously used photocatalysts. The prepared cerium‐doped WO3 nanoparticles as a sun light driven photocatalyst, may be utilized for industrial wastewater purification.

In vitro antibacterial response of ZnO‐MgO nanocomposites at various compositions

“…Additionally, the crystallite size of the composite decreased drastically in comparison to their pristine counterparts. This reduction of size is accompanied by a decline in the intensity of the peak and shift toward higher Bragg angles meaning compressive residual stresses are dominant over tensile stresses 28‐30 . In addition, a decrease in crystallite size also indicates activation of localized defects which is also validated by estimated crystallite size and dislocation line density (consult Table 1).…”

“…The lower bandgap reduces/ affects the recombination time of electron and hole pairs which significantly affects the radical and H 2 O 2 (ROS) generation and stability. In contrast, the rate of recombination enhances with a decrease in bandgap 28 . Conversely, an increase in bandgap significantly improves recombination stability of electron and hole pair which remains stable for a longer period inspite of the relatively higher energy required to initiate the reaction 28 .…”

“…In contrast, the rate of recombination enhances with a decrease in bandgap 28 . Conversely, an increase in bandgap significantly improves recombination stability of electron and hole pair which remains stable for a longer period inspite of the relatively higher energy required to initiate the reaction 28 . Hence, the above‐mentioned nanocomposite combination (MgO:ZnO ratio of 1:3 and 3:1) has intermediate effective band gaps ( E g ) of 4.56 and 4.80 ev accordingly.…”

Martian regolith—Ti6Al4V composites via additive manufacturing

“…As a result, a shift toward higher 2 θ represents smaller lattice parameters or a reduction in crystalline sizes. Compressive residual stresses mainly cause this reduction, whereas higher tensile residual stresses are accompanied by an increase in crystalline size and reduction in Bragg angles 28,30,31 . Also, in the higher range of 2 θ , peak broadening and reduction are presented in Figure 3C.…”

“…Compressive residual stresses mainly cause this reduction, whereas higher tensile residual stresses are accompanied by an increase in crystalline size and reduction in Bragg angles. 28,30,31 Also, in the higher range of 2θ, peak broadening and reduction are presented in Figure 3C. Accordingly, the highest peak in DED Ti64 is located at 2θ of 64 • , whereas two other prominent peaks are presented at 2θ of 53 • and 71 • .…”