eV For TiO2 Research Articles

Green synthesis and characterization of TiO2 and Ag-doped TiO2 nanoparticles for photocatalytic and antimicrobial applications

TiO2 and Ag-doped TiO2 nanoparticles were synthesized using lemon grass plant leaf extract via a greener co-precipitation method. Plant biomolecules facilitated nanoparticle production, ensuring stability. Characterization involved XRD, FE-SEM, XPS, FT-IR, EDX, UV-DRS, HR-TEM and UV–Vis spectroscopy analyses, revealing tetragonal and cubic structures for TiO2 and Ag-TiO2, with average sizes of 11.96 and 41.8 nm, respectively. FT-IR confirmed characteristic bands, FE-SEM and HR-TEM analysis reveal that Ag-doped TiO2 nanoparticles primarily form irregular agglomerations, with interplanar spacings of 0.362 nm for the anatase (220) plane and 0.235 nm for the silver (111) plane and EDX determined elemental composition. UV–DRS calculated band gap values (3.3 eV for TiO2, 0.9 eV for Ag-TiO2). Photocatalytic performance against methylene blue dye under sunlight indicated higher degradation by Ag-TiO2 (96.96 %) than TiO2 (77.77 %). Antimicrobial testing showed superior activity of Ag-TiO2 over TiO2.

“Enhancing wastewater treatment: DFT and experimental insights into ZnO-implanted TiO2 Z-scheme photocatalyst mediated via Smilax aspera"

This comprehensive study aimed to optimize the performance of photogenerated carriers in catalytic and optoelectronic systems by effectively separating electron-hole pairs. Green-synthesized TiO₂ nanoparticles (average size ∼21 nm) and zinc acetate (99.5 % purity), augmented with eco-friendly integration of the plant Smilax aspera, resulted in a tailored hollow direct Z-scheme photocatalyst, ZnO–TiO₂, with adjustable ZnO loading ranging from 0.5 wt% to 5 wt%. Characterization techniques such as X-ray Diffraction, Fourier Transform Infrared Spectroscopy, Ultraviolet–Visible Spectroscopy, Transmission Electron Microscopy, Thermogravimetric Analysis and Energy-Dispersive X-ray Spectroscopy provided detailed insights into the atomic and electronic properties of the material. The analysis revealed the coexistence of anatase TiO₂ and wurtzite ZnO phases, each exhibiting distinct electronic band structures within the composite. Density functional theory calculated band gap values of 2.02 eV for TiO₂ and 2.89 eV for ZnO–TiO₂ corroborated the experimental results, offering a deeper understanding of electronic transitions within the heterojunction. The ZnO–TiO₂ composite showed significant photocatalytic efficacy in degrading Methylene Blue (98 % in 15 min) and Rose Bengal (79.69 % in 40 min) under UV light. It also exhibited antifungal potential against Aspergillus niger and Candida albicans, with inhibition zones of 28.0 ± 0.12 mm and 30.23 ± 0.68 mm, respectively. This research provides valuable insights into the eco-friendly, multifunctional applications of the ZnO–TiO₂ Z-scheme photocatalyst. This research thus provides valuable insights into the multifaceted applications of this synergistic, eco-friendly heterojunction photocatalyst in environmental remediation and its role as an effective antifungal agent.

Development of Bio-Photoelectrochemical Hybrids for Solar Energy Conversion

Recent advancements in solar energy conversion have identified bio-photoelectrochemical hybrids as one of the most promising sustainable techniques. This study integrates BiVO4 and TiO2 semiconductors with photoautotrophic microorganisms (e.g., Algae) to enhance solar energy conversion. Thin films of these materials were prepared and characterized, revealing a relatively smooth surface for BiVO4 while structures for TiO2 thin films deposited as nanorods. Optical properties showed band gaps of ≤ 3.1 and 2.4 eV for TiO2 and BiVO4, respectively. The point of zero charge of materials was investigated, indicating that naturally occurring biofilm formation might not be favorable for as-prepared materials. To overcome this challenge, we aimed to use polyelectrolytes to enhance attachment of cells on the surface of semiconductor and in this regards we determined the biocompatibility of using this approach. Photoelectrochemical (PEC) measurements were conducted to evaluate solar energy conversion efficiency. This study offers insights into optimizing biosystem attachment, biofilm stability, and PEC performance of coupled semiconductors with photoautotrophic microorganisms as one photoelectrode in PEC cell, advancing sustainable solar energy conversion technologies.

Synthesis and characterization of α-Fe2O3 Nanoparticles and α-Fe2O3 /TiO2 Nanocomposite and application them in a solar cell

Abstract:
 Nanostructures of metal oxides of TiO2 and α-Fe2O3 are prepared through the hydrothermal method. Also α-Fe2O3/TiO2nanocomposites are prepared by the hydrothermal technique using an and α-Fe2O3 /TiO2 nanocomposites are mixed in the equal ratio. The properties of the prepared compounds are investigated through Field Emission Scanning Electron Microscopy (FE-SEM), Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD). The optical properties of prepared compounds are studied through UV-Vis Spectroscopy, X-ray diffraction patterns of prepared TiO2, and α-Fe2O3 have shown a( monoclinic structure, Tetragonal, and Hexagonal ) respectively. The optical band gap is (3.0, 1.6 and 2.7) eV for TiO2, α-Fe2O3 NPs and CuO/TiO2/α-Fe2O3nanocomposites. Dye-sensitized solar cells (DSSCs) fabricated based on TiO2, α-Fe2O3 NPs and α-Fe2O3 /TiO2/ nanocomposites are casted onto (FTO) substrates (front electrode). while the back electrode is a carbon/FTO-glass substrate. Two natural dyes of dyes are used green leek dye and red pomegranate dye whereas iodine/ iodide (KI/I2) is used as the electrolyte solution.. The solar cells efficiency rates (0.65, 1.38 and 0.96) for TiO2, α-Fe2O3 Nps and α-Fe2O3 /TiO2/ nanocomposites/re d pomegranate dye respectively. and The solar cells' efficiency rates are (0.69, 1.93 and1.29) for TiO2, and α-Fe2O3 /TiO2/ nanocomposites/ green leek dye respectively

Preparation and comparison performance of CuO Nanopartecles and CuO/TiO2 / Nanocomposite and application in solar cell

Nanostructures of metal oxides of CuO, and TiO2 were prepared by the hydrothermal method. Also, CuO/TiO2 nanocomposites were prepared by the hydrothermal technique using an equal ratio of 1:1 The properties of the prepared compounds were investigated through Field Emission Scanning Electron Microscopy FE-SEM, Transmission Electron Microscopy TEM, X-Ray Diffraction. The images of FE-SEM have confirmed that the prepared TiO2 , CuO, and nanoparticles were structured as Nanoparticles, Spherical, and CuO/ TiO2 nanocomposites which were mixed in an equal ratio were structured as rocks-like structures. The results of the X-ray diffraction indicated the presence of CuO, and TiO2 as (monoclinic structures, Tetragonal) respectively. with the average crystallite sizes,( 13.10,8.65 and 10.12)nm, for CuO , TiO2 and CuO/TiO2 respectively. The optical properties of the prepared nanoparticles CuO , TiO2 , and CuO/TiO2 were studied through UV-Vis Spectroscopy. The optical band gap of the prepared products was determined by UV-Visible spectrophotometry and was found to be 2.1, 3.0, and 2.8 eV for TiO2, CuO, NPs, and CuO /TiO2 nanocomposites respectively. Dye-sensitized solar cells (DSSCs) fabricated based on TiO2, CuO, NPs, and CuO /TiO2 nanocomposites are casted onto (FTO) substrates (front electrode), while the back electrode is carbon/FTO-glass substrate. Two types of natural dyes were used in this study. Chlorophyll pigment in green leek and anthocyanin red pigment in cochineal pomegranate whereas iodine/ iodide KI/I2 is used as the electrolyte solution. The solar cells efficiency rates (1.51,0.74 and 0.94) for CuO, TiO2 NPs, and CuO /TiO2 nanocomposites/ are chlorophyll pigments present in green leek respectively. and The solar cells efficiency rates (1.20,0.558 and 0.88) for CuO, TiO2 Nps, and CuO/TiO2 nanocomposites/ anthocyanin pigment present in red pomegranate respectively

Optical and gas sensing properties of TiO2/RGO for methanol, ethanol and acetone vapors

• Preparation of TiO 2 /RGO nanocomposite by annealing method at 180 °C. • Employing TiO 2 /RGO nanocomposite toward sensing methanol, ethanol and acetone vapors with different ppm. • Observation an excellent response for ethanol detection even in low gas volume. Reduced graphene oxide and metal oxides derivatives are introduced as relatively benign materials for improving gas sensors' performance as exemplified by the synthesis of TiO 2 /GO nanocomposite via ultrasonication, and then the assembly of RGO adorning TiO 2 nanoparticles (NPs) (TiO 2 /RGO) is accomplished using the thermal annealing method. The characterization of the as-fabricated sample indicated that irregular shaped TiO 2 NPs with size of 26 nm covered the RGO nanosheets. The optical band gap measurement indicated the values of 3.19, 2.1 and 2.5 eV for TiO 2 , GO and TiO 2 /RGO samples, respectively. The ensued nanocomposites are then deployed for the gas sensing response of three common organic vapors of ethanol, methanol, and acetone with concentrations of 20, 40, 60, 80, 100 ppm, at ambient temperature. The TiO 2 /RGO sensor relatively exhibited an excellent response (3–4 times) for ethanol detection. These results indicated that the application of TiO 2 /RGO can help assist in the evolvement of portable gas sensing devices endowed with the capability to detect common place organic vapors.

Photocatalytic degradation of phenol by core–shell Cu@TiO2 nanostructures under visible radiation

Even allowing high degradation efficiency, TiO2 does not support many large-scale applications, mainly due to the high operational cost related to the use of artificial radiation sources. On the other hand, it is well known that the TiO2 response to solar radiation can be increased by association with noble metals, due to the phenomenon of surface plasmonic resonance. Thus, the present study aimed to prepare copper nanoparticles and their incorporation into commercial titania (Evonik Aeroxide P-25) by the wet impregnation method. Characterization studies confirmed the formation of a core–shell nanostructure (Cu@TiO2) formed by irregular shape particles with a mean size between 20 and 30 nm. The incorporation of Cu significantly reduced the optical bandgap energy (Eg) of the materials, ranging from 3.17 eV for TiO2 P-25 to 2.67 eV for Cu@TiO2 materials containing 3.0% of copper. Characterization studies carried out by cathodoluminescence shown that high concentrations of copper reduced the lifetime of photogenerated electrons and holes, which suggests its role as a charge recombination center. Thus, the presence of copper decreased the efficiency of TiO2 on the UV–Vis mediated photocatalytic degradation of phenol, while in the presence of visible radiation only Cu@TiO2 materials containing 0.5% of copper showed high degradation efficiency.

Sol-gel synthesis and characterization of Ho3+ doped TiO2 nanoparticles: Evaluation of absorption efficiency and electrical conductivity for possible application in perovskite solar cells

Titanium dioxide (TiO2) and holmium (1.2 mol% Ho3+) doped TiO2 nanoparticles were synthesized via sol-gel method using polyvinylpyrrolidone (PVP) co-polymer as a pore forming agent. The nanoparticles were dispersed in a solvent and drop-cast on a glass substrate to make films. The films were then calcined at 550 °C for 4 h in a pre-heated muffle furnace. Methylammonium lead iodide (MAPbI3) was incorporated with TiO2 and TiO2:Ho3+ nanoparticles. Therefore, the samples TiO2, TiO2:Ho3+, TiO2:MAPbI3 and TiO2:Ho3+:MAPbI3 were obtained and their properties as an electron transporting and photon absorption layers, respectively, were evaluated for possible application in perovskite solar cells. XRD results revealed a rutile phase which was found to be consistent with the RAMAN analysis. FESEM showed spherical nanoparticles with irregular pore size for TiO2 and TiO2:Ho3+ samples, whereas MAPbI3 nanocrystals seemed to have filled-up the pores in TiO2:MAPbI3 and TiO2:Ho3+:MAPbI3 samples. UV–Vis results showed an expected UV absorption of TiO2 with the absorption band at ∼366 nm and upon doping with 1.2 mol% of Ho3+ ions, an improved absorption and a shift towards the visible region was observed. Small absorption bands at ∼453, 541 and 645 nm were detected, which are resulting from the Ho3+ transitions. When MAPbI3 was incorporated with TiO2:Ho3+, absorption in the visible range remained improved with the bands at ∼541 and 645 becoming intense. TiO2:MAPbI3 sample showed a further absorption improvement with a red-shift of the absorption band. The band gap energy was estimated and found to be ∼3.00, 2.35, 2.32 and 2.34 eV for TiO2, TiO2:Ho3+, TiO2:MAPbI3 and TiO2:Ho3+:MAPbI3, respectively. The red-shift and the reduction of the bandgap values is a good indication that these materials will absorb as much photons in the visible and near-infrared regions. The current-voltage (I–V) analysis revealed that the sample TiO2:MAPbI3 have higher current flow, implying lower resistance in the material. The PL results indicated low electron-hole recombination as the intensity was considerably decreased upon doping with Ho3+ and incorporating MAPbI3.

A Dual‐Functional Titanium Nitride Chloride Layered Matrix with Facile Lithium‐Ion Diffusion Path and Decoupled Electron Transport as High‐Capacity Anodes

AbstractIntercalation typed electrodes are expected with low theoretical capacity, which falls behind their high rate performance and stability. In this work, α‐TiNCl, an isoelectronic system of TiO2, is designed as a promising high‐capacity intercalation anode. TiNCl features are layered TiN backbone terminated by Cl atoms. While the rocksalt TiN backbones function as electron conductors, the interlayer voids provide Cl‐coordinated Li+ sites without strong Li‐Ti repulsion, which proves to be a rapid diffusion path with a low energy barrier (0.06 vs 0.47 eV of TiO2). Therefore, a dual‐functional TiNCl matrix is established for Li+ and e– transport. To stabilize the layered structure, TiNCl is scaffolded by an in situ grown TiO2 coating, which also serves as an electron reservoir during lithiation. The TiNCl‐TiO2 anode exhibits significantly large Li+ intercalation capacity (243% of TiO2) and outstanding battery performance (231 mA h g–1 at ≈17 C for 2500 cycles, 94 mA h g–1 at ≈34 C for 10 000 cycles). The (+) LiCoO2 || TiNCl‐TiO2 (–) full battery maintains 170 mA h g–1 for 300 cycles. This work may shed light on the molecular engineering of new compounds for electrodes.

Fabrication of ZnO and TiO2 Nanotubes via Flexible Electro-Spun Nanofibers for Photocatalytic Applications.

Web-like architectures of ZnO and TiO2 nanotubes were fabricated based on a three-step process of templating polymer nanofibers produced by electrospinning (step 1). The electrospun polymer nanofibers were covered by radio-frequency magnetron sputtering with thin layers of semiconducting materials (step 2), with FESEM observations proving uniform deposits over their entire surface. ZnO or TiO2 nanotubes were obtained by subsequent calcination (step 3). XRD measurements proved that the nanotubes were of a single crystalline phase (wurtzite for ZnO and anatase for TiO2) and that no other crystalline phases appeared. No other elements were present in the composition of the nanotubes, confirmed by EDX measurements. Reflectance spectra and Tauc plots of Kubelka–Munk functions revealed that the band gaps of the nanotubes were lower than those of the bulk materials (3.05 eV for ZnO and 3.16 eV for TiO2). Photocatalytic performances for the degradation of Rhodamine B showed a large degradation efficiency, even for small quantities of nanotubes (0.5 mg/10 mL dye solution): ~55% for ZnO, and ~95% for TiO2.

Microwave-assisted sol–gel synthesis of TiO2-mixed metal oxide nanocatalyst for degradation of organic pollutant

Abstract Titanium dioxide (TiO2) is the most effective photocatalysts for low-cost degradation of organic pollutant; however, the wide band gap and the high recombination rate of the charge carriers are drawbacks that hinders it practical application. In this study, TiO2 and titanium mixed metal oxides ternary (V/Ag/TiO2) nanocatalyst was synthesized through a microwave-assisted sol–gel route using Ti(C4H9O)4, NH4VO3, and AgNO3 as precursors. The XRD analysis of the synthesized TiO2 and V/Ag/TiO2 depicts lattice fringes for rutile and anatase crystalline phases. Raman spectra indicate the formation of a mesoporous multiphase sample mixture of rutile and anatase phases. The spectrum shift to the visible light region was demonstrated by the UV-visible spectroscopy analysis. Diffuse reflectance spectroscopy (DRS) reveals a reduced band gap of 2.9 eV for TiO2 and 2.65 eV for V/Ag/TiO2. Brunauer–Emmett–Teller (BET) indicates a large surface area of 92.8 and 84.8 m2 g−1 for TiO2 and V/Ag/TiO2, respectively. Nitrogen adsorption–desorption isotherm exhibits type IV isotherm, signifying the presence of the mesoporous structure. SEM portrays a cluster of rod-like aggregate particles, while the HRTEM analysis illustrates nanoparticles of rod-like cylindrical shape with a homogeneous size diameter. The synthesized nanocatalyst demonstrated a significant photocatalytic ability in the degradation of methyl orange (MO) and methylene blue (MB). V/Ag/TiO2 shows higher activity in the visible region. Thus, the present report suggests efficient, suitable, and economical microwave-assisted sol–gel techniques to yield V/Ag/TiO2 nanocatalysts with harnessed photocatalytic performance for the degradation of toxic organic pollutants in the presence of visible light irradiation.

Photo-catalytic degradation of bisphenol-a from aqueous solutions using GF/Fe-TiO2-CQD hybrid composite.

In this photocatalytic study, removal of bisphenol-A from aqueous solution was studied using the GF/Fe-TiO2-CQD composite. Due to its health and environmental effects, this compound should be disposed of sources that are mainly industrial wastewater. The phis-chemical properties of the composite were determined by traditional analyzes of EF-SEM, EDX, BET, XRD, FTIR and DRS. In this study, different ratios of CQD in the composite (1.5, 4.5 and 7.5wt%), pH, and bisphenol-A concentration as variable parameters were investigated. All analyzes, EF-SEM, EDX, BET, XRD, FTIR, show that the GF/Fe-TiO2-CQD composite is well coated on glass fibers (GF) and all the elements in the catalyst are present. On the other hand, DRS analysis showed that CQD reduces the band gap of Fe-TiO2 from 2.96eV to 2.91eV, it was 3.10eV for TiO2. Among different catalysts, GF/Fe-TiO2-CQD4.5wt% has the best performance. The results showed that for GF/Fe-TiO2-CQD4.5wt%, optimum for the process was at pH = 6 in low concentration of bisphenol-A. The first order model for the photocatalytic degradation process were well studied. In addition, GF/Fe-TiO2-CQD4.5wt% showed that it can be used many times with a minimal reduction in performance. As a result, the GF/Fe-TiO2-CQD4.5wt% composite can successfully remove bisphenol-A form in synthetic aqueous solution. However, it is necessary to further studies to applied that for real water source in water and wastewater treatment plants.

Solar Hydrogen from Glycerol-Water Mixture

The photocatalytic activity of titania supported bimetallic Cu-Ni photocatalysts were assessed for hydrogen production from water and also a mixture of glycerol-water system under visible light illumination. Addition of 2.0 mL glycerol to 8.0 mL water enhanced the solar hydrogen production from 6.1 mL to 9.5 mL. If metal was not incorporated onto TiO2 , the hydrogen production was minimal, 2.0 mL after 2 hr reaction. The band gap for bimetallic Cu-Ni/TiO2 was 2.78 eV compared to 3.16 eV for TiO2 . Photooxidation of glycerol produced glyceraldehyde, glycolic acid and oxalic acid.

Immobilized TiO2/ZnO Sensitized Copper (II) Phthalocyanine Heterostructure for the Degradation of Ibuprofen under UV Irradiation

Photocatalytic coatings of TiO2/ZnO/CuPc were developed on stainless steel substrates by subsequent sol gel dip coating for TiO2, spray pyrolysis for ZnO, and spin coating for copper (ii) phthalocyanine (CuPc) deposition. The latter compound was successfully prepared using a Schiff-based process. The materials and coatings developed were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy with attached energy dispersive spectroscopy (SEM-EDS), UV-Vis spectroscopy, room temperature photoluminescence (RTPL) spectroscopy, H1-nuclear magnetic resonance (1H-NMR) spectroscopy, C13-nuclear magnetic resonance (13C-NMR) spectroscopy, and matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry (MS). The as-deposited TiO2/ZnO/CuPc on stainless steel retained in pristine state the structural and morphological/spectroscopic characteristics of its respective components. Estimated energy band gap values were 3.22 eV, 3.19 eV, 3.19 eV for TiO2, ZnO, TiO2/ZnO respectively and 1.60 eV, 2.44 eV, and 2.92 eV for CuPc. The photocatalytic efficiency of the fabricated TiO2/ZnO/CuPc coatings was tested toward ibuprofen (IBF). After 4 h irradiation under 365 nm UV, an increased degradation of about 80% was achieved over an initial 5 mg/L ibuprofen (IBF). This was much higher compared to about 42% and 18% IBF degradation by TiO2/ZnO and TiO2 thin film, respectively. In all cases, the stability of the best-performing photocatalyst was investigated showing a small decline to 77% of IBF degradation after the 5th cycle run. The effect of pH, reactive oxygen species (ROS) probe, shed light on a possible catalytic mechanism that was suggested.

A novel route to obtain TiO2 nanoparticles using green synthesis with vanillin and Bougainvillea glabra Choisy extract

In this work, we present two green routes, as an alternative method to traditional synthesis, to obtain TiO2 nanoparticles (NPs) from vanillin (TiO2_V) and Bougainvillea glabra Choisy flower extracts (TiO2_B) as suitable non-toxic reducing agents due to their potential to reduce their environmental impact and cost during the synthesis process. The NPs presented an anatase phase as confirmed by X-ray diffraction, and with crystallite sizes of 6.10 nm (TiO2_V) and 5.89 nm (TiO2_B), their hydrodynamic size and morphology were characterized by dynamic light scattering and scanning electron microscopy, respectively. Infrared spectroscopy confirmed TiO2 characteristic bands for the obtained materials and from their UV–Vis absorption spectra band gap values of 3.07 and 3.08 eV for TiO2_V and TiO2_B, respectively, were calculated. Additionally, Gratzel cells were prepared to investigate the efficiency of the NPs obtained by this green synthesis. Finally, we included a theoretical section where, from ab initio calculations of structural and electronic properties, we explain the role of the reducing agents of the employed experimental synthesis, finding that the radicals restrict the grown-up of the clusters by the passivation of the dangling bonds modifying the crystal structure of the clusters splitting the t2g orbitals, altering the band gap of the clusters.

In situ fabrication of ternary TiO2 doped grafted chitosan/hydroxyapatite nanocomposite with improved catalytic performance for the removal of organic dyes: Experimental and systemic studies

A hetero-structured photocatalysts with enhanced mineralization capacity has been obtained significant consideration due to their improved performance in environmental purification process. Wrapping of TiO2 and hydroxyapatite with suitable biopolymer will improve the specific surface area, porosity, stability and provides enhanced degradation efficiency. Herein, TiO2 reinforced hydroxyapatite (TiO2@CS-Hpt) nanocomposite matrix was synthesized proficiently by co-precipitation technique. Here, chitosan acted as a spine in the fabrication and afforded the surface for a composite generation. Photocatalysis was the method used universally for elimination of inorganic and organic impurities from water. Herein, an integrated flexible TiO2 imprinted chitosan/hydroxyapatite (TiO2@CS-Hpt) composite was fabricated and utilized for treating water contaminated with of Methylene Blue (MB) and Rhodamine B (RhB) dyes, via photo-degradation method. The prepared TiO2@CS-Hpt was characterized extensively using FTIR, XRD, SEM-EDX, TEM, PL and UV/Vis-DRS techniques. X-ray photoelectron spectroscopy served to confirm that the dyes underwent photo-reduction. The DRS results implies the reduction in band gap to of TiO2@CS-Hpt 2.01 eV as against 3.23 eV of TiO2. The results specified that the maximum degradation were 98.6 % and 96.7 % for MB and RhB respectively, in the experiment with the initial dye concentration 50 mg L−1, 0.1 g L−1 of photocatalyst, TiO2@CS-Hpt, pH 7 and under 120 min of light exposure. The photocatalyst reusability has been retained up to seven cycles and the practical applicability for the treatment of water/wastewater was ensured by field trial.

Microstructure and photocatalytic activity of TiO2-SiO2 composite materials

TiO2-SiO2 composite materials with different composition (from 0 to 50 mol % SiO2) were prepared by sol-gel method. Microstructure, optical property and photocatalytic activity of TiO2-SiO2 composite materials were characterized by Raman scattering, ultraviolet-visible (UV-vis) spectrometer and photocatalytic degradation of methylene blue. The Raman spectra results showed that TiO2-SiO2 composite materials contained only a single crystalline phase of anatase TiO2. It also indicated the inclusion of SiO2 suppressed the growth of anatase TiO2. The UV-vis absorption spectra showed that the absorption edge of TiO2-SiO2 composite materials has a blue shift as the SiO2 increased. The optical band gap of TiO2-SiO2 increased from 3.06 eV to 3.32 eV for TiO2 and 0.5TiO2-0.5SiO2. The adsorption performance and photocatalytic activity of TiO2-SiO2 was enhanced with the increase of SiO2 content. 0.5TiO2-0.5SiO2 has the best absorption performance and photocatalytic activity in our experiment. And it has potential application value in the field of photocatalytic materials.

NANOCRYSTALLINE SnO2/TiO2 FOR SOLAR CELLS APPLICATION

The developments in the field of solar cells need to create a new material to improve the electrical properties, which leads to an increase in conversion efficiency. So, in this paper, nanocrystalline Tin dioxide (SnO2) as a thin film were synthesized and deposited on Titanium dioxide using chemical Spray pyrolysis thechniqe (CSPT). The mixed aqueous solution of Tin chloride (SnCl2) was prepeared at room temperature using magnatic stirr and sprayted on glass slide at 300 °C. Our results indicated that the prepared films are smooth, homogeneous and have good adhesion to the substrate. The results of structural properties revealed that the synthesis films are polycrystalline in nature with prefer orientations (110) and (101) for SnO2 and TiO2 respectively. The optical properties results using UV-Vis spectrophotometer analysis shows that high transmittance (grater than 70 %) and wide optical energy gap 3.97, 3.93 and 3.88 eV for TiO2, SnO2 and SnO2/TiO2 respectivly.

Cu/Al Layered Double Hydroxide by Co-precipitation with High Anti-UV Performance in Waterborne Varnish

The Cu/Al layered double hydroxide (Cu/Al LDH) with a Cu2+/(Cu2+ + Al3+) molar ratio of 0.81 was prepared via co-precipitation at pH 5.18 using a mixing solvent with DMSO, glycerol and water. The band gap of 2.58 eV is smaller than 3.07 eV of TiO2. Better anti-UV irradiation, and transparency were observed based on 0% gloss reduction loss after UV ageing.

Sustainable and easy recoverable magnetic TiO2-Lignocellulosic Biomass@Fe3O4 for solar photocatalytic water remediation

This work was undertaken to design a magnetic TiO2 hybridized with lignocellulosic biomass (olive pits: OP) for dyes and Cr(VI) photocatalytic removal from water. Firstly, TiO2-OP was synthetized by ultrasonic-assisted sol-gel process, and then TiO2-OP@Fe3O4 was obtained via hydrothermal magnetization at 180 °C. Materials were characterized by XRD, BET, UV-DRS and XPS. The as-prepared photocatalysts showed a visible light responsive, wherein, Eg values are 3.20, 3.02, 3.00 and 2.55 eV for TiO2, TiO2@Fe3O4, TiO2-OP and TiO2-OP@Fe3O4, respectively. While the specific surface area values were as follows: 22.94, 15, 55.1 and 104.7 m2/g for TiO2, TiO2@Fe3O4, TiO2-OP and TiO2-OP@Fe3O4, respectively. Photocatalytic activities of TiO2@Fe3O4, TiO2-OP and TiO2-OP@Fe3O4 were tested for the photocatalytic removal of three dyes (Rhodamine B (RhB), Methylene blue (MB) and Congo Red (CR)) and hexavalent chromium under visible light. It was found that TiO2-OP@Fe3O4 composite exhibited higher adsorption and photocatalytic abilities compared with TiO2@Fe3O4 and TiO2-OP. The oxidation rates using TiO2-OP@Fe3O4 were 100, 75 and 81% within 1 h for MB, RhB and CR, respectively, at a dye concentration of 10 ppm and photocatalyst mass of 0.25 g/L. While the photocatalytic reduction rates of Cr(VI) (10 ppm, pH 3) were 64% (within 60 min), 70% (within 60 min) and 100% (within 40 min) by TiO2@Fe2O3, TiO2-OP and TiO2-OP@Fe3O4, respectively. The effect of pH, MB concentration, photocatalyst dose, co-presence of metallic cations and Tert-butyl alcohol concentration (as OH scavenger) on the MB oxidation was studied. Since the composite showed an excellent magnetic recoverability and high photocatalytic efficiency, it could be a potential candidate in industrial wastewater treatment.