Synthesis, characterization and photocatalytic applications of Zn-doped TiO2 nanoparticles by sol–gel method

Abstract

Mesoporous, nanocrystalline, Zinc-doped TiO 2 nanoparticles were synthesized by surfactant-assisted solgel method. The X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET), and UV-VIS spectrometer techniques were used to characterize the synthesized products. XRD results confirm the formation of the anatase phase for the TiO 2 nanoparticles, with crystallite sizes in the range of 12.6-18.1 nm. The small crystallite size and doping with Zinc ion inhibit phase transformation and promote the growth of the TiO 2 anatase phase. The SEM and TEM micrographs revealed the spherical-like morphology with average diameter of about 12-18 nm which is in agreement with XRD results. The optical study shows that doping ions lead to an increase in the absorption edge wavelength and a decrease in the band gap energy of titania. Photocatalytic activity of the synthesized nanomaterials was successfully tested for photodegradation of methyl red as model pollutant under UV light. The photocatalytic activity results confirm that the doped nanoparticles show higher activity than undoped titania. The small grain size, high crystallinity, high specific surface area and decrease in the band gap energy of doped titania may be responsible for the high photocatalytic activity.

Insights into the TiO2-Based Photocatalytic Systems and Their Mechanisms

“…The mechanism of cation doping is essentially to tune the Fermi level and electronic structure of d-electron configuration in TiO 2 , thereby to tune the energy levels to absorb the visible light energy and to enhance the overall photocatalytic efficiency of the system as shown in Figure 4a Consequently, there have been many cations doped in TiO2 towards enhancing its PC activities. In such cation doping, TiO2 has been doped with the (i) transition metals such as Sc, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Cd, and W [73][74][75][76][77][78][79][80][81][82][83][84]; (ii) rare-earth metals such as Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er, Yb, and La [85][86][87][88][89]; and (iii) other metals such as Li, Mg, Ca, Se, Sr, Al, Sn, and Bi [90][91][92][93][94][95][96][97]. In the case of rare earth elements doping, the electronic configurations such as 4f, 5d, and 6s are found to be favorable to tune the band edge positions, density of states, and width of VB and CB via altering the crystal, electronic, and optical structures in TiO2 [98][99][100].…”

TiO2 Nanopartikülü ve TiO2/Aktif Çamur Sentezi ile Sulu Çözeltiden Cu (II) İyonlarının Adsorpsiyonu

“…Saf TiO 2 nanopartikülleri, sol-jel yöntemi ile sentezlenmiştir (Aware ve Jadhav 2016). Çalışma kapsamında ön başlatıcı olarak bir alkoksit olan Titanium(IV)-iso-propoxide (TIP) kullanılmıştır.…”

Effect of doping Fe/Cu/Ti on WO3 on furfural degradation

“…Doping titanium enhances larger bandgap energy when compared with undoped and commercial WO 3 due to its wider bandgap energy, which would act as the pathway of electrons transition. However, there should be aware of doping amount as if too minimal bandgap energy might bring about electrons-holes recombination [19][20]. 3 2.65 1%Fe-WO 3 2.53 2%Fe-WO 3 2.47 3%Fe-WO 3 2.42 1%Cu-WO 3 2.63 2%Cu-WO 3 2.57 3%Cu-WO 3 2.48 1%Ti-WO 3 2.64 2%Ti-WO 3 2.70 3%Ti-WO 3 2.70…”