TiO2 SiO2 Hybrid Research Articles

Optimal Suppression of Photocatalytic Activity of Hybrid TiO2 Particles in Epoxy Thin Film by Using Taguchi Method

In this study, two different Al2O3-TiO2 and SiO2-TiO2 hybrid TiO2 particles were synthesised by using silica (SiO2) and alumina (Al2O3) to suppress the photocatalysis of TiO2. Key variables such as the concentration of the hybridization material (C), heating temperature (Th), and calcinating temperature (Tc) were selected with performance measured by photodegradation rate. The Taguchi L9 orthogonal array, a systematic approach used in the design of experiments (DOE), confirmed A333 (Al2O3-TiO2) achieved 99% photodegradation suppression with photodegradation rate reduced significantly from 0.01305 min−1 to 0.00009 min−1 and improved yellowing resistance by 63%, while S323 (SiO2-TiO2) achieved 75% suppression with photocatalysis activity decreased from 0.01305 min−1 to 0.0033 min−1 and 42% improved resistance. X-ray Diffraction (XRD) analysis showed A333 had a higher rutile phase (40.1% vs. 10.2% for S323), and Fourier Transform Infra Red (FTIR) and Field Emission Scanning Electron Microscopy (FESEM) analyses revealed A333's rougher surface and lower surface area compared to S323 and pure TiO2. Overall, A333 effectively suppressed photocatalysis and improved yellowing resistance of epoxy thin film. Copyright © 2024 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Artificial neural network model of non-Darcy MHD Sutterby hybrid nanofluid flow over a curved permeable surface: Solar energy applications

The conversion of solar radiation to thermal energy has recently much interest as the requirement for renewable heat and power grows. Due to their enhanced ability to promote heat transmission, nanofluids can significantly improve solar-thermal systems' efficiency. This section aims to study the heat transfer behavior of the Sutterby hybrid nanofluid flow of magnetohydrodynamics in the presence of a non-uniform heat source/sink and linear thermal radiation over a non-Darcy curved permeable surface. A novel implementation of an intelligent numerical computing solver based on multi-layer perceptron (MLP) feed-forward back-propagation artificial neural network (ANN) with the Levenberg-Marquard algorithm is provided in the current study. Data were gathered for the ANN model's testing, certification, and training. Established mathematical equations are nonlinear, which are resolved for velocity, the temperature in addition to the skin friction coefficient, and the rate of heat transfer by using the bvp4c with MATLAB solver. The ANN model selects data, constructs and trains a network, then evaluates its efficacy via mean square error. Graphs illustrate the impact of a wide range of physical factors on variables, including pressure, velocity, and temperature. In the entire study, the thermal energy improved by the SiO2 (silicon dioxide) - Au (gold) hybrid nanofluid than the SiO2-TiO2 (titanium dioxide) hybrid nanofluid. The higher internal heat generation/absorption parameter values increase the temperature.

Effect of TiO2–SiO2 hybrid nanofluids on enhanced oil recovery process under different wettability conditions

Effect of TiO2–SiO2 hybrid nanofluids on enhanced oil recovery process under different wettability conditions

Efficiency enhancement of building multi-layer solar collector with SiO2–TiO2 hybrid nanofluids

Efficiency enhancement of building multi-layer solar collector with SiO2–TiO2 hybrid nanofluids

Sol-gel synthesis of TiO2-SiO2 hybrid films with tunable refractive index for broadband antireflective coatings covering the visible range

Sol-gel synthesis of TiO2-SiO2 hybrid films with tunable refractive index for broadband antireflective coatings covering the visible range

Thermo-physical Properties of TiO2-SiO2 Hybrid Nanofluids Dispersion with Water/Bio-glycol Mixture

Introducing nanoparticles in liquid-based mixtures began to gain attention in various industries. This is supported by previous studies to improve the performance and provide energy saving for the system. Among its uses is in the VCRS and automotive air conditioning (AAC) system. The lubricant used in this system has the potential to have a good effect on the performance. Before testing the nano-lubricant enhancement performance, an automotive air conditioning (AAC) system test rig based on hybrid electric vehicles (HEV) AC system has to be developed; therefore, this paper presented the development process of AAC test rig specific for the HEV. In order to analyze the performance, 11 thermocouples, digital pressure gauges with the data logger, and AC/DC power clamp were assembled and used. After that, the experiment was conducted with five different initial refrigerant charges and three different compressor speeds. This method was applied to both pure POE lubricant and SiO2/POE nano-lubricant. Then, the heat absorbs, compressor work, and coefficient of performance (COP) were evaluated. The highest average COP for SiO2/POE nano-lubricant was achieved at a 40 % duty cycle (2520 RPM) speed with a value of 2.84. The highest enhancement of the COP is 25.1% at 60% duty cycle (3180 RPM) speed with 160 grams of initial refrigerant charged an average enhancement of the COP is 13.16%.

Stability and thermo-physical properties of green bio-glycol based TiO2-SiO2 nanofluids

The investigation on thermal properties of nanoparticles dispersed in the mixture of water and green Bio-glycol are limited in the literature and only available for single nanofluids. The purpose of this study is to investigate the stability and thermo-physical properties of green Bio-glycol based TiO2-SiO2 nanofluids. In the present study, the hybrid nanofluids were prepared at various volume concentrations of 0.5 to 3.0% by dispersing TiO2 and SiO2 nanoparticles (20:80) in water and Bio-glycol (40:60) mixture base fluids. The stability of green Bio-glycol based TiO2-SiO2 nanofluids showed physically to be in good range of stability for suspension nanoparticles with zeta potential of −53.46 mV. The thermal conductivity of the green Bio-glycol based TiO2-SiO2 nanofluids was enhanced up to 12.52% higher than the mixture of W/BG at 3.0% volume concentration and temperature of 70 °C. Meanwhile, there is insignificant dynamic viscosity increment of the green Bio-glycol based TiO2-SiO2 nanofluids with temperature. As a conclusion, a stable TiO2-SiO2 hybrid in green Bio-glycol/water mixture nanofluids was formulated in the present study with significant enhancement in thermal properties and recommended for heat transfer application. Further heat transfer investigation is required to confirm the feasibility of the green coolant.

Molecular dynamics simulation and thermo-mechanical characterization for optimization of three-phase epoxy/TiO2/SiO2 nano-composites

In this research, experimental and theoretical method are used to improve and optimized the thermo-mechanical properties of hybrid Epoxy/TiO2/SiO2 nano-Composites. For investigation of the influence of weight percentage of Silica toward Titana in TiO2–SiO2 hybrid nanoparticles on tensile properties of epoxy, the composite was optimized by surface methodology. Thirteen experiments were designed by using design expert commercial software totally. The TiO2–SiO2 hybrid nanoparticles were synthesized by sol-gel method. Then, epoxy/TiO2–SiO2 nanocomposites were prepared by direct mixing method. Four factors as elongation at break (EAB), yield strength (σy), ultimate strength (σu) and elastic modulus (E) were investigated by using tensile test device. The optimization results showed that the best (EAB), (σy), (σu) and (E) outcomes are 29.3, 17.72, 17.43 and 4.34% respectively with 14.64% weight percent of Silica in total amount of TiO2–SiO2 0.73% hybrid nanoparticles. In order to investigate the chemical and thermo-mechanical properties of nanocomposite as tensile tests, TGA, XRD, FT-IR, SEM, EDX and DRS analysis were performed. In addition, due to the high reliability in predicting the reaction among different materials and comparing with the results of experimental work, which is based on polymer-nanoparticle interaction energy, molecular dynamics simulation (MD) were used. The simulations were performed by using materials studio (MS) software. The numerical and analytical results show that the presence of small amount of Silica beside Titanium creates a strong interaction between fillers and epoxy resin.

Synthesis and characterization of nanoparticles and composites as bactericides

In the present study, SiO2-TiO2 hybrid nanomaterial and zeolite-TiO2 (Z-TiO2) composites were synthesized by the sol-gel method. Then, the antibacterial activity of the above-mentioned synthesized materials, SiO2 and zeolite (Z) was investigated by the disk diffusion method using Echerichia coli and Enterobacter aerogenes as test microorganisms. All the materials showed antibacterial activity against E. coli with 7.2, 10.7, 3.5 and 8.2 mm of inhibition zone for SiO2-TiO2 hybrid nanomaterial, SiO2, zeolite and Z-TiO2 composite, respectively. However, none of them showed antibacterial activity against E. aerogenes. The obtained results pointed out that these natural-based materials (i.e. Z, SiO2, Z-TiO2 and SiO2-TiO2), known to be noncarcinogenic and nontoxic, can be used as disinfectants against E. coli (an important indicator of the bacteriological quality of water) as safe and eco-friendly alternatives to chlorine.

Design and analysis of graphene–MoS2 hybrid layer based SPR biosensor with TiO2–SiO2 nano film for formalin detection: numerical approach

In this paper, a Surface Plasmon Resonance (SPR) biosensor has been numerically developed that used Graphene–MoS2–Au–TiO2–SiO2 hybrid structure for the detection of formalin. This developed sensor has been sensed the presence the formalin based on attenuated total reflection (ATR) method by observing the change of “surface plasmon resonance angle-the change of minimum reflectance attributor” and “the resonance frequency characteristics (RFC)-maximum transmittance attributor”. Chitosan has been used as probe sensing medium to accelerate particular reaction with the formalin. Here, graphene is used as biomolecular recognition element because of its high adsorption ability and optical characteristics which helps to improve sensor sensitivity, MoS2 used for it has larger band gap, high fluroscence quenching ability, higher optical absorption efficiency, TiO2–SiO2 bilayer as the improvement of sensitivity and Gold (Au) as the sharp SPR curve. Numerical results give the impression that the variation of RFC and SPR angle for improper sensing of formalin is quiet negligible that confirms no formalin is detected whereas for proper sensing these change are considerably countable that confirms the detection of formalin. From the sensor sensitivity analysis, owing to add TiO2–SiO2 bilayer with Graphene–MoS2 Hybrid layer, maximum sensitivity of 85.375% has been numerically resulted. This high sensor performance is for taking advantages of Graphene surface high selectively which detect bio molecular compounds through pi-stacking force, larger work function (5.1 eV) of MoS2 which allows the high sensitive detection of bio targets and Rich plasmon happens at the TiO2–SiO2 interface.

Electrospinning synthesis of SiO2-TiO2 hybrid nanofibers with large surface area and excellent photocatalytic activity

Abstract In this paper, one-dimensional SiO2-TiO2 nanofibers with large surface area and high anatase thermal stability were prepared by a facile and economical electrospinning technique. The phase transformation characters of the samples with different Si/Ti ratios and calcined at different temperatures were investigate in detail. The characterization results indicate that the modification of SiO2 could effectively prevent phase transformation of TiO2 from anatase to rutile. When the Si/Ti ratio increases from 0% to 5%, TiO2 crystals changed from mixed phases of anatase and rutile to pure anatase phase after heat treated at 600 °C. Meanwhile, the surface area of 600–5% is as high as 95.96 m2/g, which is nearly 12 times that of 600–0% (8.17 m2/g). Optimization of electrospun SiO2-TiO2 nanofibers shows that SiO2-TiO2 composite nanofibers with Si/Ti ratio = 2%, calcined at 600 °C, exhibited the highest MO degradation efficiency. The mole ratios of Si/Ti above and below 2% showed negative effect on MO degradation. This study serve as significant advancement platform to designing and fabricating high efficient and stable SiO2-TiO2 composite nanofibers via facile electrospinning in a “waterless” system and it is believed to make sense in other semiconductor systems which are sensitive to moisture.

Graphene-MoS2 with TiO2[sbnd]SiO2 layers based surface plasmon resonance biosensor: Numerical development for formalin detection

In this article, numerically a surface plasmon resonance (SPR) biosensor is developed based on Graphene-MOS2with TiO2SiO2 hybrid structure for the detection of formalin. Based on attenuated total reflection (ATR) method, we used angular interrogation technique to sense the presence the formalin by observing the change of “minimum reflectance with respect to SPR angle” and “maximum transmittance with respect to surface plasmon resonance frequency (SPRF)”. Here, we used Chitosan as probe analyte to perform chemical reaction with formalin (formaldehyde) which is consider as target analyte. Simulation results show a negligible variation of SPRF and SPR angle for improper sensing of formalin that confirms absence of formalin whereas for proper sensing is considerably countable that confirms the presence of formalin. Thereafter, a comparison of sensitivity for different sensor structure is made. It is observed that the sensitivity without TiO2, SiO2, MoS2 and Graphene (conventional structure) is very poor and 73.67% whereas the sensitivity with graphene but without TiO2, SiO2 and MoS2 layers is 74.67% consistently better than the conventional structure. This is due to the electron loss of graphene, which is accompanying with the imaginary dielectric constant. Furthermore, the sensitivity without TiO2, SiO2 and graphene but with MoS2 layer is 79.167%. After more if both graphene and MoS2 are used and TiO2 and SiO2 layers are not used then sensitivity improves to 80.5%. This greater than before performance is due to the absorption ability and optical characteristics of graphene biomolecules and high fluorescence quenching ability of MoS2. Further again, if TiO2SiO2 composite layer is used with the Graphene-MoS2 then the sensitivity enhances from 80.5% to 82.5%. Finally, the sensitivity for the proposed structure has been carried out, and result is 82.83%, the highest value among all the previous structures to integrate the advantages of graphene, MoS2, TiO2 and SiO2.

Laser irradiation synthesis and photocatalytic properties of TiO2-SiO2 hybrid thin films

In this study, we introduce a noble method for the fabrication of highly crystalline hybrid TiO2-SiO2 thin films using laser irradiation under ambient conditions. Upon light absorption at the interface between TiO2 sol-gel film and Si wafer during the laser irradiation process, the TiO2 gel film coated on the Si wafer is transformed into anatase TiO2 film, and the surface of underlying Si wafer is oxidized to a 20.63 μm thick SiO2 film composed of nano-spheres with average diameter of 24.12 nm. The photocatalytic characteristics of the TiO2-SiO2 hybrid film on methylene blue and its discriminated morphologies are compared with those of a TiO2 film fabricated by conventional thermal annealing. The TiO2-SiO2 hybrid film shows enhanced super-hydrophilicity and superior photocatalytic characteristics, while thermally annealed 0.16 μm thick TiO2 films exhibit hydrophobic and low photocatalytic properties. The laser assisting process is promising for the fabrication of highly crystalline TiO2-SiO2 hybrid film with super-hydrophilic and photocatalytic characteristics.

Design and realization of antireflection coatings for the visible and the infrared based on mesoporous SiO2 and SiO2-TiO2 hybrid materials.

Five-layer antireflective coating for the visible and the infrared has been successfully fabricated by a solgel route on quartz substrate. The quarter-half-quarter multilayer structure with two buffer layers is optimized by the optical admittance approach. Mesoporous SiO2 film templated by an ethylene oxide-propylene oxide-ethylene oxide triblock copolymer is used as the top layer, and SiO2-TiO2 hybrid films are employed as the other layers. The grazing incidence small-angle x-ray scattering results indicate the ordered mesopores in the low-index SiO2 film, as well as the homogeneity of the SiO2-TiO2 hybrid films. Transmittance spectra are fitted to obtain film thicknesses and refractive indices, providing the main technological parameters for theory designs. A short heat-treatment step followed by a shock cooling process is introduced to suppress crack formation in film stacks. The transmittance of the obtained five-layer antireflective coating exceeds 99% at 500-700nm, and the maximum value in the infrared region is 97.84% at 1100nm. This work is a beneficial attempt to fabricate antireflective coatings with multilayer structure through the soft solgel route.

Sol⁻Gel-Processed Organic⁻Inorganic Hybrid for Flexible Conductive Substrates Based on Gravure-Printed Silver Nanowires and Graphene.

In this study, an organic–inorganic (O–I) nanohybrid obtained by incorporating an alkoxysilane-functionalized amphiphilic polymer precursor into a SiO2–TiO2 hybrid network was successfully utilized as a buffer layer to fabricate a flexible, transparent, and stable conductive substrate for solution-processed silver nanowires (AgNWs) and graphene under ambient conditions. The resulting O–I nanohybrid sol (denoted as AGPTi) provided a transmittance of the spin-coated AgNWs on an AGPTi-coated glass of 99.4% and high adhesion strength after a 3M tape test, with no visible changes in the AgNWs. In addition, AGPTi acted as a highly functional buffer layer, absorbing the applied pressure between the conductive materials, AgNWs and graphene, and rigid substrate, leading to a significant reduction in sheet resistance. Furthermore, gravure-printed AgNWs and graphene on the AGPTi-based flexible substrate had uniform line widths of 490 ± 15 and 470 ± 12 µm, with 1000-cycle bending durabilities, respectively.

溶胶-凝胶法制备TiO2-SiO2混合微球腔的激发高阶回音壁模式

溶胶-凝胶法制备TiO₂-SiO₂混合微球腔的激发高阶回音壁模式

Highly selective hydrogenation of levulinic acid catalyzed by Ru on TiO2-SiO2 hybrid support

Abstract Levulinic acid is an important molecule of biomass and the gamma-valerolactone (GVL) is one of the most promising compound from levulinic acid. We have developed an efficient catalyst for the catalytic conversion of LA into GVL, ruthenium based catalyst in silica, titania and a silica-titania hybrid support The prepared catalysts were characterized by TEM, XRD, TPR and nitrogen adsorption analysis. The results have shown higher catalytic activity of Ru/TiO2-SiO2 than Ru/TiO2 either Ru/SiO2. Herein, we report that yields higher than 90% were obtained for gamma-valerolactone from levulinic acid hydrogenation catalyzed by Ru/TiO2-SiO2 at 100 °C and 20 atm of hydrogen without additives.

Synthesis and properties of phase change microcapsule with SiO2-TiO2 hybrid shell

In this paper, SiO2-TiO2/paraffin phase change microcapsules with different contents of paraffin are prepared via sol-gel method. SiO2-TiO2 act as a shell and paraffin is used as a core. Scanning Electron Microscope (SEM), Laser particle size analyzer, Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffractometer (XRD), Differential Scanning Calorimeter (DSC) and Hot Disk are employed to characterize the morphology, chemical structure and thermal properties of SiO2-TiO2/paraffin microcapsules. The results show that there is no reaction between SiO2-TiO2 and paraffin. The average particle size is 11.38 μm when the encapsulation rate of paraffin is 39.8%. The latent heat and the phase change temperature of the SiO2-TiO2/paraffin microcapsule is 93.7 J/g and 29.0 °C, respectively. After 1000 times of heat storage-release cycles, the latent heat of the microcapsule was decreased by 6.58% and the encapsulation ratio was decreased by 2.62%. The thermal conductivity of the microcapsule is 11.63% higher than that of paraffin.

Sol-gel preparation of self-cleaning SiO2-TiO2/SiO2-TiO2 double-layer antireflective coating for solar glass

Self-cleaning SiO2-TiO2/SiO2-TiO2 double-layer antireflective (AR) coating is prepared by sol-gel process. SiO2 sol is prepared by using tetraethyl orthosilicate (TEOS) as precursor and ammonia as catalyst, while TiO2 sol was prepared by using tetrabutyl orthotitanate (TBOT) as precursor and hydrochloric acid as catalyst. The effect of TiO2 content on refractive index, abrasion-resistance and photo-catalytic activity of SiO2-TiO2 hybrid thin films or powders is systematically investigated. It is found that the refractive index of SiO2-TiO2 hybrid thin films increases gradually from 1.18 to 1.53 as the weight ratio of TiO2 to SiO2 increased from 0 to 1.0. The SiO2-TiO2 hybrid thin film and powder possesses good abrasion-resistance and photo-catalytic activity, respectively, as the weight ratio of TiO2 to SiO2 is 0.4. The degradation degree of Rhodamine B by SiO2-TiO2 hybrid powder is 88.3%. Finally, SiO2-TiO2/SiO2-TiO2 double-layer AR coating with high transmittance, abrasion-resistance and self-cleaning property is realized.

Cellulose acetate-based SiO2/TiO2 hybrid microsphere composite aerogel films for water-in-oil emulsion separation

The cellulose acetate (CA)/SiO2-TiO2 hybrid microsphere composite aerogel films were successfully fabricated via water vapor-induced phase inversion of CA solution and simultaneous hydrolysis/condensation of 3-aminopropyltrimethoxysilane (APTMS) and tetrabutyl titanate (TBT) at room temperature. Micro-nano hierarchical structure was constructed on the surface of the film. The film could separate nano-sized surfactant-stabilized water-in-oil emulsions only under gravity. The flux of the film for the emulsion separation was up to 667 L m−2 h−1, while the separation efficiency was up to 99.99 wt%. Meanwhile, the film exhibited excellent stability during multiple cycles. Moreover, the film performed excellent photo-degradation performance under UV light due to the photocatalytic ability of TiO2. Facile preparation, good separation and potential biodegradation maked the CA/SiO2-TiO2 hybrid microsphere composite aerogel films a candidate in oil/water separation application.