Solid TiO2 Research Articles

Synthesis mechanism of TiO2 nanoparticles via high frequency electrical arc discharge

Abstract The rapid advancement of nanofabrication techniques has significantly increased the utilization of nanoparticles in recent years. This study investigates the synthesis of titanium dioxide (TiO₂) nanoparticles, highlighting their unique properties and diverse applications across scientific and industrial fields. These nanoparticles are valued for their biocompatibility and advantageous optical, electrical, and physical properties. Various synthesis methods—chemical, physical, and biological—are reviewed, with a particular focus on the electric arc discharge method. This method is distinguished by its efficiency and environmental friendliness, enabling the production of highly pure nanoparticles. Utilizing continuous and alternating sparks between two electrodes, the technique generates spherical nanoparticles with adjustable sizes, controlled by the energy of each spark. An RC circuit-based device was designed for this electrical discharge process. Dynamic light scattering (DLS) measurements revealed an average particle size of 164.51 nm with a standard deviation of 44.08 nm. Field emission scanning electron microscopy (FESEM) images showed both solid and hollow spherical TiO2 nanoparticles. Energy dispersive spectroscopy (EDS) confirmed that the TiO2 particles contained only titanium and oxygen, with no other elements detected. X-ray diffraction (XRD) analysis verified the crystal structure, predominantly identifying the anatase phase of the synthesized nanoparticles. This research enhances the understanding of TiO2 nanoparticle synthesis and characterization, providing a foundation for future innovations in their extensive applications.

Phase equilibria of the Na2O‐TiO2‐SiO2 system between 900 and 1600°C in air

AbstractThe Na2O‐SiO2‐TiO2 system is important for the glass, ceramic, and metallurgical industries. Its features provide information on the composition and melting temperature to be utilized during the production of glass and ceramic and during the processing of TiO2‐bearing material in the metallurgical industry. The liquidus temperatures between 900 and 1600°C in the ternary system at saturation of solid SiO2, TiO2, Na2Ti6O13, Na2SiTiO5, and Na2Ti3O7 were measured using the equilibration‐quenching energy‐dispersive X‐ray spectroscopy/Electron Probe Microanalyzer technique. A wide range of liquidus compositions were obtained with Na2O between 0 and 41.7 mol% in the SiO2‐ and TiO2‐rich regions. The present study provides liquidus data at 1500 and 1600°C for the first time. Liquidus temperatures at various double saturations were also obtained in the present investigation to determine univariant lines in the phase diagram. The present experimental data were compared with previous investigations and computed phase diagrams. The data obtained in the present investigation can be employed to optimize the thermodynamic properties and phase diagrams of the Na2O‐SiO2‐TiO2 system.

Influence of Ti addition on the microstructure and comprehensive properties of Mo–Cu alloy

To enhance the overall performance of Mo–Cu alloy, Ti was added to Mo–Cu alloy to improve the bonding strength of Mo/Cu interface and generate solid solution strengthening effect. The outstanding performances of Mo–Cu–Ti alloys were achieved by infiltrating Cu–Ti alloy with different compositions into the Mo skeleton. Compared to the incoherent interface of Mo/Cu in Mo–Cu alloy, the addition of Ti transformed its interface to the coherent interface of Mo–Ti/Cu–Ti. All Mo–Cu–Ti alloy blocks had higher relative densities (97.4%∼98.5%) to guarantee the excellent comprehensive performances. What's more, the existences of Mo–Ti and Cu–Ti solid solutions assured the alloy possessed relatively high mechanical strength. The introduction of Ti purified the grain boundary by absorbing oxygen to generate TiO2 which hindered the growth of Mo–Ti grains. As increasing Ti amount from 0 wt% to 4.62 wt%, the Mo–Ti (or Mo) grain size reduced from 5 μm to 4.1 μm. Notably, Mo–Cu alloy block with the addition of 2.30 wt% Ti possessed the highest tensile strength of 562 MPa. Additionally, since the finer grain size of Mo–Ti alloy, this sample also owned the maximum micro-hardness and bending strength of 268 HV and 1730 MPa, respectively. Nevertheless, the presences of Cu–Ti solid solution and TiO2 also destroyed the electrical conductivities of the samples to some extent.

Microstructure and high-temperature oxidation resistance of in-situ Al2O3 reinforced AlCrFeTiV high-entropy alloy with boron microalloying

In this study, the effect of boron (B) on the microstructure and high-temperature oxidation resistance of AlCrFeTiV high-entropy alloy (HEA) coatings were investigated via laser cladding on Ti-6Al-4 V. The study findings indicate that AlCrFeTiVBx (x=0, 0.5, and 1 at%) HEAs coatings mostly comprise BCC solid solution phase, TiO2 and Al2O3 ceramic particles, which formed by oxygen (O) in the air reacts with Titanium (Ti) and Aluminum (Al) of coatings. Besides, the introduction of minor B should effectively reduce the formation of TiO2. Increasing the B content, significantly promoted the high-temperature oxidation resistance of HEAs coatings at 900 °C for 50 h. When x = 1, the coating exhibits the best high-temperature oxidation resistance. Furthermore, the oxidation mechanism of the coating was studied using first-principles calculations, and further investigation was utilized on the charge transfer of oxygen adsorbed on the BCC (1 0 0) surface.

Layered oxide precursor strategy for the synthesizing of titanium oxynitrides

Oxynitride is a mixture of mixed oxide and nitride anions. The creation of simple synthesis methods remains a challenge. Herein, we propose a synthetic method that uses the layered oxide Cs0.68Ti1.83O4 precursor to directly create oxynitride Ti2.85O4N without the need for ammonia. Using a topochemical reaction at 500 °C, a combination of solid Cs2CO3 and TiO2 was converted into the layered oxynitride Cs0.68+xTi1.83O4-xNx.‬‬‬‬‬‬ The crystal structure of Ti2.85O4N has been analyzed by Rietveld refinement with synchrotron radiation data. The UV–Vis spectra revealed that Ti2.85O4N has an absorption edge around 650 nm. Ti2.85O4N exhibits photocatalytic activity for hydrogen evolution utilizing methanol as a reversible electron donor in the visible range (λ > 420 nm) when promoted by platinum. In contrast, the intermediate oxynitride Cs0.68+xTi1.83O4−xNx with surface NHx species does not exhibit photocatalytic activity. These findings open new opportunities for novel titanium oxynitrides photocatalysts.‬‬‬‬‬‬‬

Magnetic and Dielectric Properties of 0.1 Bi2/3Cu3Ti4O12 -0.9 Bi3LaTi3O12 Nanocomposite Prepared by Semi-Wet Route

INTRODUCTION: A chemical formula of nanocomposite 0.1 Bi2/3Cu3Ti4O12 -0.9 Bi3LaTi3O12 (BCLT-19) was prepared by semiwet route using metal nitrate and solid TiO2. The phase formation of Bi2/3Cu3Ti4O12 (BCT) and Bi3LaTi3O12 (BLT) was confirmed by X-ray diffraction (XRD) study. METHOD: Transmission electron microscope (TEM) analysis showed a nano particle of size 14 ± 5 nm on average for BCLT-19 composites. Scanning electron microscope (SEM) images exhibited a tubular, spherical and heterogeneous structure of grains. The root means square roughness, average roughness and maximum area peak height were explained by atomic force microscopy (AFM). RESULT: Study of magnetic properties was determined as weak antiferromagnetic to ferromagnetic and in nature. The high dielectric constant (ε' = 3147 at 100Hz to 500 K) of BCLT-19 may be due to the existence of space charge polarization. CONCLUSION: In this manuscript have studies on the novel composite materials of BCLT-19 micro-structural properties. This is useful for future Random-access memory devices and dielectric materials,

Novel physical sunscreen from one-dimensional TiO[formula omitted] nanowire: Synthesis, characterization and the effects of morphologies and particle size for use as a physical sunscreen

The performance of the one-dimensional (1D) morphology as an inorganic UV filter for sunscreens of titanium dioxide (TiO2) was evaluated in this research. The 1D TiO2 nanowires were prepared using solid TiO2 and 10 M NaOH as precursors via a modified hydrothermal method, followed by calcination at 400–900°C for 5 h. The influences of TiO2 loading, hydrothermal time and calcination temperature were studied on the morphologies of the as-prepared samples. The morphologies of the TiO2 nanowires were investigated using SEM and TEM techniques. The results found all the variables directly affected the particle size and shape of the TiO2 nanowires. The hydrothermal synthesis conditions using a TiO2 loading of 0.2 g at 220°C for 24 h (HTiO2) resulted in a particle size that was the longest and narrowest in length and diameter, respectively. The first product from the hydrothermal synthesis is H2Ti3O7, which can transform into TiO2(B) (TiO2@400), anatase (TiO2@700) and rutile (TiO2@900) by calcination at 400, 700 and 900 °C, respectively. The calcined samples were selected for a porcine skin penetration study. The 1D morphology particles were localized on the stratum corneum of the skin, while the comparison spherical particle penetrated the deeper layer. From the SPF test, the highest SPF is TiO2 anatase.

Ice Adhesion Evaluation of PTFE Solid Lubricant Film Applied on TiO2 Coatings

Ice formation affects the performance of many industrial components, including aircraft wings, spacecraft, and power transmission cables. In particular, ice build-up on airplane components increases drag and fuel consumption. A large number of studies have been carried out to reduce ice adhesion by developing passive methods such as icephobic coatings and active ice removal approaches such as mechanical vibrations or chemical-based solutions. Despite remarkable recent breakthroughs in the fabrication of icephobic coatings, passive ice removal solutions require higher durability to resist cyclical mechanical ice detachment treatments. Functionalized TiO2 coatings, applied using the suspension plasma spray (SPS) technique, have been shown to be robust and to have dual-scale characteristics in an ice accretion analysis. In this study, the icephobicity and mechanical durability of a novel duplex coating consisting of polytetrafluoroethylene (PTFE) solid lubricant films on TiO2-coated substrates were evaluated. Notably, various amounts of PTFE were applied on top of the TiO2 coating to identify the ideal quantity required to obtain optimal icephobic properties. Ice was generated in an icing wind tunnel, and the amount of accreted ice was evaluated to assess the anti-icing properties. Wettability parameters, including static water contact angle and contact angle hysteresis, were measured to determine the water mobility and surface energy. Ice shear adhesion to the PTFE-TiO2 duplex coating was measured using a custom-built test rig. The mechanical durability was assessed by measuring the ice shear strength for almost twenty icing–deicing cycles, and after five cycles, the roughness parameters and images taken from the surface of the samples were compared. The combination of PTFE solid lubricant film and TiO2 coating reduced ice adhesion by 70%–90% compared to that of a bare aluminum substrate (reference material). Additionally, the results showed that the application of a uniform layer of PTFE solid lubricant film on dual-scale TiO2 coating significantly reduced ice adhesion and maintained mechanical durability for 25 deicing cycles, making this combination a promising candidate for deicing approaches.

Optical and photocatalytic properties of TiO2–Bi2O3–CuO supported on natural zeolite for removing Safranin-O dye from water and wastewater

A series of n–p heterojunction catalysts (TiO2–Bi2O3–CuO) were synthesized by the ceramic method. X-ray diffraction, scanning electron microscopy coupled with energy dispersive X-ray, Fourier transform infrared spectroscopy (FTIR), UV–visible spectroscopy, and photoluminescence were used for the characterization of the synthesized materials. The optical optimization demonstrated that the solid solution TiO2–0.2Bi2O3–0.25CuO exhibited the best optical property. This catalyst supported on natural zeolite under ultrasonic waves improved notably the adsorption-photodegradation capacity of the resultant material. The impact of the n–p junction supported on zeolite on the photodegradation of a polluting solution showed excellent results for the degradation of cationic dye with removal efficiency reaching 94.1% and 80.23% under sunlight for Safranin-O dye in distilled water and in wastewater from a local textile dyeing plant.

Effective and selective electrocatalytic nitrate reduction to ammonia on urchin-like and defect-enriched titanium oxide microparticles

This work reported a facile approach to surface oxygen vacancy (OV)-enriched urchin-like TiO2 microparticles (U-TiO2), which were highly effective and durable in catalyzing selective nitrate reduction to ammonia (NO3RR). Specifically, the U-TiO2 delivered a mass activity of 1.15 min−1 mg−1catalyst, a low yield of toxic NO2−-N intermediate (≤0.4 mg/L) and an exceptional high NH3-N selectivity of 98.1% in treating 22.5 mg/L of NO3−-N under a potential of -0.60 V vs. RHE, outperforming most of the reported oxide-based catalysts. When comparing the performance of U-TiO2 with that of the solid amorphous TiO2 counterpart (A-TiO2) that had close particle size but more OV on surfaces, we identified that the OV was the reactive sites, but rather than its content, the NO3RR kinetics were primarily limited by the electron and mass transfer at U-TiO2/water interfaces. Accordingly, the superior performance of U-TiO2 to A-TiO2 could be ascribed to the hierarchical urchin-like structure in U-TiO2. The in-situ DEMS test revealed that the NO3RR on U-TiO2 followed a pathway of *NO3− → *NO2−→ *NO → *N → *NH → *NH2 → *NH3. We also demonstrated that the U-TiO2 could keep its robust performance under a wide NO3−-N concentration range and in the presence of some co-existing ions (such as Ca2+, Cl−, Mg2+). However, the presence of humic acid and CO32− in water slowed down the NO3RR on U-TiO2. This work provides a more fundamental insight into the OV-driven NO3RR process on TiO2, which should benefit for the development of efficient TiO2-based catalysts.

Titanium dioxide Ag NP enhanced solid solar cell electrodes for favourable efficiency

Population growth leads to a heightened demand for working potential to support modern commercial and residential evolutions. Available conventional energy sources, however, cause environmental pollution and severe health problems like global warming. The current energy sources also face challenges due to factors like global warming that make hydro-generated energy production even more difficult due to droughts. Therefore, alternative energy options need to be explored. The study in question aimed to find a cost-effective and environmentally friendly energy source by fabricating a solar cell that uses titanium dioxide and potassium iodate (mixed in carbon) layers in a solidified structure. TiO2 was chosen due to its photo-generating properties and synthetic steadiness over a spread acidity/basicity neutrality. The iodine/iodide complex was used to replenish the photo-excited electrons while graphite facilitated their migration. The researchers varied the ingredients capacities for the separate electrodes keeping the rest unvaried for improved (I-V) terminal parameters. Deduction from the research established that the (0.4:0.3:0.17:0.01) TiO2/CX:I2:KI proportions resulted in the optimum charge range generation. The inclusion of potassium iodate (KI) improved iodine solvability and facilitated even dispersal in graphite, which was maintained at 0.01 g in all cells. The absorber and receptive layer thicknesses of 2.00 mm and 1.00 mm respectively generated the best 0.979 V open-circuit voltage (Voc) and 12.037 μA short-circuit current (Isc) results. Favorable (10.46%) efficiency (η) and (0.64) fill factor (FF) were derived. Conducting transparent glass was suggested for improving the linkage to the external circuit and models of reducing air pockets in the solid TiO2 photovoltaic devices could further enhance their performance.

The role and effects of Ru1−xTixO2 solid solution transition layer in Ru/TiO2 composite photocatalyst by DFT calculations

In order to more clearly analyze the effects of Ru cocatalyst on TiO2 photocatalyst, two typical Ru1−xTixO2 solid solutions were selected as the transition layer of Ru/TiO2 hetero-structure for further in-depth analysis and discussion in this work, based on our previous works. The interface mismatch and interface formation energy between Ru1−xTixO2 solid solution transition layer and TiO2 layer or RuO2 layer are lower. Therefore, the introduction and existence of Ru1−xTixO2 solid solution transition layer can reduce the interface stress and imbalance of abrupt-type RuO2/TiO2 hetero-structure and make it more stable. By bridging oxygen atoms on the interface, electron transfer occurs between Ru1−xTixO2 solid solution transition layer and TiO2 layer or RuO2 layer, so as to form a smoother electrostatic potential distribution between them. More importantly, the pseudo-bandgap value of the selected Ru1−xTixO2 solid solution transition layer is between the bandgap values of TiO2 or RuO2, which can form a transition band offset between them. This effect reduces the unfavorable large band offset of abrupt-type RuO2/TiO2 hetero-structure. The above effects illustrate that the introduction of Ru1−xTixO2 solid solution transition layer can ensure the effective synergy of Ru cocatalyst, so as to significantly improve the quantum conversion efficiency of Ru/TiO2 composite photocatalyst.

HETEROGENEOUS CATALYTIC FRACTIONATION OF BIRCH-WOOD BIOMASS INTO MICROCRYSTALLINE CELLULOSE, XYLOSE AND ENTEROSORBENTS

For the first time, it was proposed to fractionate the main components of birch wood into microcrystalline cellulose, xylose and enterosorbents by integrating heterogeneous catalytic processes of acid hydrolysis and peroxide delignification of wood biomass. The hydrolysis of wood hemicelluloses into xylose is carried out at a temperature of 150 °C in the presence of a solid acid catalyst Amberlyst® 15. Then the lignocellulosic product undergoes peroxide delignification in a "formic acid – water" medium in the presence of a solid TiO2 catalyst to obtain microcrystalline cellulose (MCC) and soluble lignin. Under the determined optimal conditions (100 °С, Н2О2 – 7.2 wt.%, НСООН – 37.8 wt.%, LWR 15, time 4 h), the yield of MCC reaches 64.5 wt.% and of organosolvent lignin 11.5 wt% from the weight of prehydrolyzed wood. By the treatment of organosolvent lignin with a solution of 0.4% NaHCO3 or hot water the enterosorbents were obtained, whose sorption capacity for methylene blue (97.7 mg/g) and gelatin (236.7 mg/g) is significantly higher than that of the commercial enterosorbent Polyphepan (44 mg/g and 115 mg/g, respectively). The products of catalytic fractionation of birch wood are characterized by physicochemical (FTIR, XRD, SEM, GC) and chemical methods.

Influence of phosphorus on the NH3-SCR performance of CeO2-TiO2 catalyst for NOx removal from co-incineration flue gas of domestic waste and municipal sludge

Domestic waste and municipal sludge are two major solid hazardous substances generated from human daily life. Co-incineration technology is regarded as an effective method for the treatment of them. However, the emitted NOx-containing exhaust with high content of phosphorus should purified strictly. CeO2-TiO2 is a promising catalyst for removal of NOx by NH3-SCR technology, but the effect of phosphorous in the exhaust is ambiguous. Therefore, the effect of phosphorus on NH3-SCR performance and physicochemical properties of CeO2-TiO2 catalyst was investigated in our present work. It was found that phosphorus decreased the NH3-SCR activity below 300 °C. Interestingly, it suppressed the formation of NOx and N2O caused by NH3 over-oxidation above 300 °C. The reason might be that phosphorus induced Ti4+ to migrate from CeO2-TiO2 solid solution and form crystalline TiO2, which led to the destruction of Ti-O-Ce structure in the catalyst. So, the transfer of electrons between Ti and Ce ions, the relative contents of Ce3+, and surface adsorbed oxygen, as well as the redox performance were limited, which further inhibited the over-oxidation of NH3. In addition, phosphorus weakened the NH3 adsorption on Lewis acid sites and the adsorption performance of NO + O2, while increased the Brønsted acid sites. Finally, the reaction mechanism over CeO2-TiO2 catalyst did not change after introducing phosphorus, L-H and E-R mechanisms co-existed on the surface of the catalysts.

Development of optimized triaxially electrospun titania nanofiber‐in‐nanotube core‐shell structure

AbstractOne dimensional (1D) nanostructures and its derivatives can be manipulated to serve special functions like hollow structure, and higher surface area. 1D TiO2 nanotube‐in‐nanofibers (NF@NT) are developed through triaxial electrospinning followed by a calcination process. A blended solution of polyvinyl pyrrolidone and tetra‐butyl titanate is used in outer and inner layers of nanofibers, respectively, while paraffin oil is used in the middle layer. The optimized triaxial nanofibers of 669.4 ± 52.43 nm are developed at 7.5 w/w% concentration, 28 kV applied voltage, and 24 cm spinning distance. TiO2 NF@NT structure is obtained through calcination of optimized triaxial nanofibers at 550°C. Subsequently, the morphology of TiO2 NF@NT and its uniform diameter distribution is confirmed through scanning electron microscopy. Fourier‐transform infrared spectroscopy results indicates the formation of TiO2 NF@NT. X‐Rays diffraction pattern peaks also reveals the presence of both anatase and rutile crystalline phases. The presence of only titanium (Ti) and oxygen (O) elements in the TiO2 NF@NT is confirmed through energy dispersive X‐ray spectroscopy. Brunauer–Emmett–Teller analysis indicates that TiO2 NF@NT has a higher specific surface area of ~141.68 m2/g compared with the solid TiO2 nanofiber (~75.31 m2/g). This study can be adopted to develop TiO2 NF@NT for wide range of application.

Demonstration of bright x-ray sources from solid and foam TiO2 targets at the Shenguang-III prototype laser facility

Enhancement of x-ray sources from laser-produced plasmas is significant in wide-ranging applications. Solid and foam TiO2 targets were both used to generate bright x-ray sources at the Shenguang-III prototype laser facility, with a total laser power of 3.2 TW. The new foam targets were with an ultra-low initial density of 8.1 mg/cm3 and a high Ti fraction of 33 sat. %. By absolute measurements, the multi-keV x rays of the 4 keV–7 keV band and 1.6 keV–4.4 keV band and the total x rays above 0.1 keV of the foam target have simultaneously shown conversion enhancements of 1.4, 3.1, and 2.3 times, respectively, compared with the solid target. A much larger emission volume and an average electron temperature of 3.2 keV by moving the foci of laser beams inner were obtained for the foam target, providing a good condition for multi-keV x-ray production.

Influence of CaxSr1−x(0⩽x⩽1) Substitution for Zn on Microwave Dielectric Properties of Li2ZnTi3O8 Ceramic as Temperature Stable Materials

A temperature stable Li2Zn0.95(SrxCa1−x)0.05Ti3O8 (0⩽x⩽1) ceramics were fabricated using a conventional solid-state route sintered at 1100 °C for 4 h. The XRD results indicate that the main phase Li2ZnTi3O8 and secondary phase including Sr1Ca1−xTiO3 (0⩽x⩽1) solid solution and TiO2 co-exist in composite and form a stable composite system when the (CaxSr1−x) (0⩽x⩽1) substitutes for Zn of Li2ZnTi3O8 ceramic. As x is increased from 0 to 1, the relative permittivity (er) increases from 26.65 to 27.12, and the quality factor (Q×f) increases from 63 300 to 66 600 GHz. With the increased of x, the temperature coefficient of resonant frequency (τf) increases from 0.27 to 8.23 ppm/°C, and then decreases to 3.51 ppm/°C. On the whole, the Li2Zn0.95(SrxCa1−x)0.05Ti3O8 (0⩽x⩽1) ceramics show excellent comprehensive properties of middle er = 25–27, higher Q×f ⩾ 60000 GHz and τf ⩽±8.5 ppm/°C.

One-Dimensional Mesoporous Anatase-TiO2/Rutile-TiO2/ZnTiO3 Triphase Heterojunction with Boosted Photocatalytic Hydrogen Production Activity

The rational design of heterojunction photocatalysts with unique mesoporous structure is of significant importance for obtaining enhanced conversion efficiency of solar energy to hydrogen energy. In present work, for the first time, anatase-TiO2/rutile-TiO2/ZnTiO3 (TiO2(A-R)/ZnTiO3) heterojunction photocatalysts with a unique mesoporous structure were synthetized by a foaming agent assisted electrospinning method. The obtained mesoporous TiO2(A-R)/ZnTiO3 nanofibers photocatalyst showed the highest hydrogen generation rate (887.7 μmol·g−1·h−1) without use of any co-catalytic noble metals, which was approximately 2.0, 2.2 and 1.4 times higher than those of ordinary solid TiO2(A-R)/ZnTiO3, mesoporous TiO2(A-R) and mesoporous TiO2(A)/ZnTiO3 nanofibers, respectively. Significantly, the archived hydrogen generation rate is also better or comparable to the some ever reported 1D TiO2 based photocatalysts. The unique 1D mesoporous nanostructure would make the reactants and products migrating easily into/out of the photocatalyst while the closely-coupled triphase heterojunction can significantly favor the separation of photogenerated electron–hole pairs, thus synergistically contributing to the improved photocatalytic activity. We also proposed that three types of charge transfer routes over the heterojunction photocatalysts, named “waterfall”, “concave” and “convex”, might concurrently promote the separation of photoinduced electrons and holes in this triphase photocatalyst system, thereby efficiently boost the photocatalytic hydrogen production activity.

Screen printed multifunctional TiO2 photoanode with plasmonic Ag nanoparticles for performance enhancement of dye sensitized solar cell

Multifunctional TiO2 powder consisting of solid microspheres/nanoparticles (NPs) was obtained in single step hydrothermal method. The insights of mesoporous solid TiO2 microspheres are observed as interconnected particles granules in the field emission scanning electron microscope (FESEM) investigation. Secondly, Ag nanoparticles (AgNPs) of spherical shaped with narrow size distribution was synthesised by reduction process and its extinction maximum at 413 nm was observed from UV–Vis analysis. Screen printed TiO2 photoanode containing plasmonic AgNPs was utilised to construct the dye sensitized solar cell (DSSC). The efficiency and optical properties of the bare and plasmonic devices were compared. Noticeable improvement in device efficiency is attributed to plasmonic properties of the incorporated AgNPs.

Investigation of convective heat transfer enhancement for nanofluid flow over flat plate

In this paper, the laminar flow over flat plate of three different nanofluids is investigated. The fluid is considered as water with three different kind of solid particles Al2O3, TiO2, and Fe3O4 of different volume fractions (1, 2, 3, and 4%). The values of viscosity, heat capacity, density, and thermal conductivity depending on volume fraction for the three nanofluids are evaluated. Numerical simulation has been conducted for analysis the impact of the nanoparticles on the heat transfer properties, on the temperature and velocity profiles, on the wall shear stress and on the skin friction coefficient. The results show that as the value of volume fraction increases the values of the wall shear stress, skin friction, and heat transfer increase, but the velocity decreases. A comparison between the three nanofluids presents the difference in the thermal enhancement, velocity profiles, and thermal boundary layer. With the volume fraction for all three nanofluids polynomial connections has been obtained to describe for the relation of the wall shear stress, skin friction coefficient and average heat transfer coefficient.