A series of cerium ion-doped titanium dioxide (Ce 3+ –TiO2) catalysts with special 4 f electron configuration was prepared by a sol–gel process and characterized by Brunauer-Emmett-Teller method, X-ray diffraction, X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance spectroscopy (DRS), and also photoluminescence (PL) emission spectroscopy. The photocatalytic activity of Ce 3+ –TiO2 catalysts was evaluated in the 2-mercaptobenzothiazole (MBT) degradation in aqueous suspension under UV or visible light illumination. The experimental results demonstrated that the overall photocatalytic activity of Ce 3+ –TiO2 catalysts in MBT degradation was signigicantly enhanced due to higher adsorption capacity and better separation of electron-hole pairs. The experimental results verified that both the adsorption equilibrium constant (Ka) and the saturated adsorption amount (Gmax) increased with the increase of cerium ion content. The results of XPS analysis showed that the Ti 3+ ,C e 3+ , and Ce 4+ ions reside in the Ce 3+ –TiO2 catalysts. The results of DRS analysis indicated that the Ce 3+ –TiO2 catalysts had significant optical absorption in the visible region between 400 and 500 nm because electrons could be excited from the valence band of TiO2 or ground state of cerium oxides to Ce 4 f level. In the meantime, the dependence of the electron-hole pair separation on cerium ion content was investigated by the PL analysis. It was found that the separation efficiency of electron-hole pairs increased with the increase of cerium ion content at first and then decreased when the cerium ion content exceeded its optimal value. It is proposed that the formation of two sub-energy levels (defect level and Ce 4 f level) in Ce 3+ –TiO2 might be a critical reason to eliminate the recombination of

for 2-mercaptobenzothiazole degradation in aqueous suspension for odour control

https://iopscience.iop.org/article/10.1088/2043-6254/ab52f7/pdf

Comparative study of crystallite size using Williamson-Hall and Debye-Scherrer plots for ZnO nanoparticles

Surfactant-assisted synthesis of photocatalysts: Mechanism, synthesis, recent advances and environmental application

Organic and inorganic antibacterial approaches in combating bacterial infection for biomedical application

Low temperature dry reforming of methane was studied over platinum (0.2–2 wt.%) and/or nickel (8 wt.%) and magnesium (8 wt.%) immobilized onto a ceria–zirconia support. Ceria–zirconia (0.6:0.4) solid solutions were synthesized by precipitation and the metals were loaded by the incipient wetness method. XRD patterns demonstrated that the support was a cubic fluorite structure and Ni and Mg were deposited onto it. Temperature-programmed reduction showed that Pt addition substantially decreased the reduction temperature and the impact became less prominent with increasing Pt loading. The Ni–Mg/(Ce 0.6 Zr 0.4 )O 2 had the highest number of basic sites and the amounts decreased with the addition of platinum. The lowest CH 4 and CO 2 conversion ( X 10 ) temperatures were achieved at 454 °C and 437 °C, respectively, using a 0.5% Pt–Ni–Mg/(Ce 0.6 Zr 0.4 )O 2 catalyst. This catalyst was optimum because it balanced between the enhanced reducibility and decreasing number of basic sites, which both occurred with increasing Pt loading. Dry reforming experiments also indicated that Pt decreased the reaction onset temperature for methane and CO 2 and correlated to a slight decrease in the H 2 :CO ratio (though still higher than for the 0.5% Pt–Ce 0.6 Zr 0.4 O 2 control catalyst). Steady-state reaction experiments were conducted between 430 and 470 °C for the best catalyst and the results showed TOFs increasing from 2.69 to 4.74 s −1 with increasing temperature and minimal deactivation when left on stream for 100.5 h. A comparison to literature indicates that the Pt/Ni/Mg/Ce 0.6 Zr 0.4 O 2 catalyst has among the highest activities, especially if Ir and Rh catalysts are not included.

Low temperature dry reforming of methane over Pt–Ni–Mg/ceria–zirconia catalysts

The effect of surfactant and dopant on the properties of zinc oxide nanoparticles were studied by preparing polyethylene glycol (PEG) capped ZnO and tungsten doped PEG capped ZnO nanoparticles via the electrochemical method. These nanoparticles were characterized using X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Ultraviolet Diffuse Reflection Spectroscopy (UV-DRS), Scanning Electron Microscopy (SEM) and Electron Dispersive Analysis of X Rays (EDAX). The photocatalytic degradation of malachite green dye using these nanoparticles was studied under visible light. The effects of various reaction parameters like dye concentration, catalyst concentration, pH and time were studied to optimize the photodegradation reaction. Reusability of these nanoparticles was studied and no significant change was observed in the degradation efficiency of PEG capped ZnO till the fourth cycle, while there was a gradual decrease in the degradation efficiency of tungsten doped PEG capped ZnO. Langmuir- Hinshelwood kinetic model well describes the photodegradation capacity and the degradation of malachite green follows pseudo-first order kinetics.Photocatalytic studies reveal that PEG capping increases the degradation properties of ZnO while tungsten doping decreases the extent of PEG capping and has a detrimental effect on the degradation properties of ZnO. The prepared nanoparticles exhibit significant antibacterial properties against gram-positive Bacillus cereus and gram-negative Escherichia coli bacterial strains by agar well diffusion method.

Electrochemical synthesis, photodegradation and antibacterial properties of PEG capped zinc oxide nanoparticles

Biogenic synthesis of g-C3N4/Bi2O3 heterojunction with enhanced photocatalytic activity and statistical optimization of reaction parameters

Ceria doped titania nano particles: Synthesis and photocatalytic activity☆

Adsorption is a possible method with distinct advantages to remediate pollution due to dyes. Sodium Lauryl Sulfate (SLS) coated ZnO nanoparticles were synthesized using the electrochemical method. The final product was dried at different temperatures, 60, 120, 150 and 300 °C. The sample dried at 60 °C was found to have the maximum SLS coating on its surface providing high negative charge density. This facilitates the adsorption of cationic dyes on its surface through electrostatic attraction. The effect of SLS on the adsorption process was confirmed by comparing it with ZnO without SLS. The effect of important parameters such as amount of adsorbent, concentration of dye, temperature and time on the percentage of adsorption was investigated using Box-Behnken design (BBD) of Response Surface Methodology (RSM). The prepared catalysts were characterized using X-ray diffraction analysis, infrared spectroscopic analysis, scanning electron microscopy, elemental detection analysis, thermogravimetric and zeta potential analysis. Finally, the study was extended to Langmuir and Freundlich isotherms in order to confirm the type of adsorption. The adsorption kinetics studies showed that it obeys pseudo second order kinetics.

Effect of surface charge and other critical parameters on the adsorption of dyes on SLS coated ZnO nanoparticles and optimization using response surface methodology

K.R. Sunaja Devi

Papers

Electrochemical synthesis, photodegradation and antibacterial properties of PEG capped zinc oxide nanoparticles

Biogenic synthesis of g-C3N4/Bi2O3 heterojunction with enhanced photocatalytic activity and statistical optimization of reaction parameters

Ceria doped titania nano particles: Synthesis and photocatalytic activity☆

Effect of surface charge and other critical parameters on the adsorption of dyes on SLS coated ZnO nanoparticles and optimization using response surface methodology

Experimental Design for Optimization of 4-Nitrophenol Reduction by Green Synthesized CeO2/g-C3N4/Ag Catalyst Using Response Surface Methodology