Pure Tin Dioxide Research Articles

SnO2QDs: Photophysical properties, photocatalytic activity, mineralization financial cost and recycling process during industrial effluent treatment

This study investigates the synthesis, characterization, and photocatalytic performance of pure and titanium-doped tin dioxide quantum dots (SnO2QDs) prepared via a sonochemical method. The structural and morphological properties were thoroughly examined using XRD, FTIR, SEM-EDX, HRTEM, UV-DRS, and BET surface area analysis. XRD confirmed the formation of tetragonal SnO2 with high phase purity and average crystallite sizes of 2.95 nm for SnO2QD1 (calcined at 270 °C) and 8.36 nm for SnO2QD2 (calcined at 480 °C). Titanium doping was achieved without altering the SnO2 crystalline structure, as evidenced by FTIR spectra showing characteristic vibrational modes and hydroxyl groups. HRTEM images revealed spherical nanoparticles with diameters of 3.2 nm for SnO2QD1 and 9.7 nm for SnO2QD2, supported by SAED patterns confirming their polycrystalline nature. The photocatalytic efficiency was evaluated through the degradation of Reactive Yellow 145 dye under Xenon lamp irradiation. SnO2QD1 exhibited superior photocatalytic activity with a rate constant (k) of 6.94 × 10−3 s−1, achieving 80 % dye degradation in 105 min, compared to SnO2QD2 with a k of 4.50 × 10−3 s−1 and 83 % degradation in 120 min. Titanium doping further enhanced the photocatalytic performance, with SnO2QDT1 (1 % Ti) showing a k of 9.89 × 10−3 s−1 and 80 % degradation in just 90 min, three times more efficient than SnO2QDT2 (9 % Ti). BET analysis indicated a significant reduction in surface area with increased calcination temperature, from 154 m2/g for SnO2QD1 to 86 m2/g for SnO2QD2. The bandgap energies, determined via UV-DRS, were 3.30 eV for SnO2QD1 and 3.34 eV for SnO2QD2, slightly reduced in Ti-doped samples, enhancing visible light absorption. The SnO2QDs demonstrated excellent recyclability, maintaining photocatalytic activity over eight reuse cycles. Economic analysis based on Saudi Arabian electricity tariffs highlighted the cost-effectiveness of SnO2QD1, offering a 5.2 % reduction in energy consumption compared to SnO2QD2. These findings position SnO2QDs as highly efficient and sustainable photocatalysts for industrial wastewater treatment applications.

Morphological Characterization of Sb-Doped SnO2 Thin Films Developed by Spray Pyrolysis

In the present work, we have successfully deposited Sb antimony doped tin dioxide (SnO2) thin films with different concentrations (0 at%, 1 at%, 3 at% and 5 at%) from a stannous (II) chloride dihydrate solution (SnCl2.2H2O), by the pyrolysis chemical spray deposition technique on ordinary microscope glass substrates preheated to a fixed temperature of 350 °C. After deposition, the films were annealed at temperatures 400 °C for 4h. The aim of this work is on the one hand to study the morphological properties of pure and doped tin dioxide thin films and to determine the different morphological parameters such as: the roughness Ra, Rq and on the other hand to study the effect of Sb doping on the morphological properties of SnO2 thin films. To achieve this purpose, the thickness of all the films was estimated by profilometer with standard scan type. The morphology of the films was examined by atomic force microscope (AFM) in contact mode at room temperature to visualize the surface of our samples (the structure, size and morphology of crystallites ... etc). The 2D and 3D AFM images confirm the formation of nanostructures on the surface, with shapes and dimensions influenced by the amount of antimony doping. All the samples show a polycrystalline morphology, and the grain size progressively decreases with the increase of the Sb concentration (1% and 3%). On the other hand, for high antimony doping (5% Sb) the grains are larger than those observed at 3% doping. The root mean square (RMS) surface roughness values for samples with Sb concentrations (5%) were found to be 8.334 nm.

Remarkable photodegradation breakdown cost, antimicrobial activity, photocatalytic efficiency, and recycling of SnO2 quantum dots throughout industrial hazardous pollutants treatment

In the conducted research, a one-step hydrothermal synthesis of pure and titanium-doped tin dioxide quantum dots is elaborated upon, with a thorough analysis of their structural, optical, morphological, and photocatalytic properties undertaken using advanced analytical techniques. Through X-ray Diffraction XRD, the crystalline nature and phase purity of the tetragonal structures of SnDs were confirmed, with the crystallite sizes measured at 3.0 nm for SnD1 and 7.66 nm for SnD2, following treatments at 240 °C and 300 °C, respectively. The structural integrity of SnO2 was maintained despite titanium doping. FTIR spectroscopy verified the existence of specific vibrational modes indicative of surface hydroxyl groups. HRTEM images revealed the spherical morphology of particles, with diameters of 3.5 nm for SnD1 and 9.1 nm for SnD2. Optical band gaps, determined through UV-DRS, ranged from 3.33 eV in SnD1 to 3.47 eV in SnDTi2. The photocatalytic degradation of Congo Red dye under xenon lamp irradiation was quantitatively assessed; notably, SnD1 exhibited a 23 % higher rate constant compared to SnD2, attributed to its smaller particle size and a 31 % greater surface area. Doping with 4 % Ti in Sn0.96Ti0.04O2 more than doubled the degradation rate compared to a 6 % Ti doping in Sn0.94Ti0.06O2. Furthermore, the generation of hydroxyl radicals was significantly enhanced, showing an increase of approximately 220 % for SnD1 and 80 % for SnD2. The capability of these nanomaterials to reduce the chemical oxygen demand of industrial organic pollutants to within regulatory limits under solar irradiation was documented, with SnD1 maintaining its photocatalytic efficiency over seven cycles of reuse. In the photocatalytic degradation rate of Congo Red dye, which was 23 % higher for SnD1 compared to SnD2, and the threefold increase in the degradation rate for SnDTi1 compared to SnDTi2. An economic assessment, based on electricity tariffs in Saudi Arabia, highlighted the cost-effectiveness of SnD1, which ranged from 26.93 to 30.36 USD per breakdown cost of the photodegradation process, showing it to be less costly than SnD2. Conversely, SnDTi1 was found to be more economical than SnDTi2, with costs ranging from 26.67 to 33.09 USD. Collectively, the results emphasize the outstanding photocatalytic performance and cost-efficiency of SnDs, reinforcing their potential as sustainable solutions for the treatment of industrial wastewater. Additionally, the antibacterial efficacy of these materials against a range of bacteria, yeast, and fungi was investigated and substantiated.

Study the effect of alpha irradiation on the optical properties of pure and doped tin dioxide thin films prepared by spin coating

Chemical spin coating is used to prepare pure and indium doped thin films of tin dioxide. All pure and doped thin films have been annealed at a temperature of 500oC. The effects of indium doping and alpha irradiation on the optical properties were studied by recording spectra of transmittance and absorbance at wavelengths (250 - 1250) nm. We found that the transmittance decreases with increasing doping concentrations, while the absorbance increases with increasing doping concentrations, whereas the allowed direct optical band gap decreases with an increase of doping. The results of this study shows that alpha irradiation causes a decrease in the band gap values, and it also effect on the optical properties such as transmittance, absorption coefficient and reflectance.

Highly Sensitive, Selective and Stable NO2 Gas Sensor Based on Porous Influenced SnO2 Bilayer Thin Films

In this work, an attempt has been made to fabricate SnO2 porous films using automated nebulizer spray pyrolysis technique with the influence of a porogen. Pure tin dioxide and porous tin dioxide (SnO2/SnO2) thin films were prepared from a precursor solution composed of SnCl2·2H2O and polyethylene glycol as a porogen. The structural, morphological, optical and gas sensing performance of the prepared thin films were characterized. The inclusion of porogen significantly improved the sensing property of porous SnO2 bilayer thin films and it was confirmed by structural, morphological and gas sensing performance studies. The optimized spray process parameter was determined finally in this work as SnO2 precursor strength of 0.2 M for porous SnO2 layer. Under this condition, the increased lattice constant, lattice defect and increased pores diameter were achieved, which exhibited good gas sensitivity and selectivity towards NO2 gas at 250 ºC. The response and recovery time is decreased as 50%, the deduction limit is 0.9 ppm. In addition, during the five weeks test, the response level was observed nearly constant, which indicated that the SnO2 bilayer sensor has long-term stability.

Some of the Study of the Physical Properties of the Membranes Binary Tin Oxide Sno2 Pure and Tinged with Nickel Ni at Different Rates Distortion

Some of the physical properties were studied, which included the optical properties of the films of pure tin dioxide doped with nickel in proportions (1,5,7%) at a molar concentration of 0.1moL/L, which were prepared by thermal chemical deposition method on glass bases at a temperature of (400ºC). The study included the optical properties through the transmittance spectrum (T) of the films of pure tin dioxide doped with banned nickel in the range of wavelengths (300-900). It was noticed that the transmittance of pure tin dioxide films is high, ranging between (82-76) % approximately in the visible region, as we have noticed that by using doping, the permeability of oxide films decreases in succession, and the reflectivity increases with the increase in the percentage of doping gradually and that the refractive index increases with the increase in the energy of the photon. The rest of the optical constants were calculated as functions of the photon's energy that smells (refractive index).

In situ and tunable structuring of semiconductor-in-glass transparent composite.

SummarySemiconductor-in-glass composites are an exciting class of photonic materials for various fundamental applications. The significant challenge is the scalable elaboration of composite with the desirable combination of tunable structure, high semiconductor loading ratio, and excellent transparency. Here we report that the topological engineering strategy via hybridization of the glass network former enables to surmount the aforementioned challenge. It not only facilitates the in situ precipitation of (Ga2-xAlx)O3 domains with continuously tunable composition but also allows to simultaneously refine the grain size and enhance the crystallinity. In addition, the composites exhibit excellent transparency and can host various active dopants. We demonstrate the attractive broadband optical response of the composite and achieve the pulse laser operation in mid-infrared waveband. The findings are expected to provide a fundamental principle of in situ modification in hybrid system for generation of high-performance semiconductor-in-glass composites.

Raman and photoacoustic spectroscopies of SnO2 thin films deposited by spin coating technique

SnO2 thin films were grown on glass substrate using a spin-coating technique. The films grown in different layers and subjected to pressure-assisted heat treatment (PAHT) were characterized by Raman spectroscopy and Photoacoustic measurements. Raman spectroscopy showed the SnO2 presence in the grown thin film and in the substrate. In addition, PAHT can change the adsorbed oxygen and the oxygen vacancies in the film. These changes strongly influence the band gap energy of samples, which were investigated by photoacoustic spectroscopy and showed a blueshift in samples after PATH treatment. A depth profile analyze with excitation on the substrate indicated a slow attenuation of the photoacoustic signal relative to tin dioxide up to 120 μm, which represents SnO2 presence up to 40 μm deep in the glass substrate. The average effective thermal diffusivity, determined by two-beam phase-lag photoacoustic method was α=(0.017 ± 0.001) cm2/s, according the literature for pure tin dioxide.

Influence of Ti doping on SnO2 thin films properties prepared by ultrasonic spray technique

Titanium doped tin dioxide (Ti-SnO2) thin films have been deposited using ultrasonic spray technique to minimize the poor properties of the pure SnO2. The process has been carried out by doping SnO2 films with the appropriate percentage of titanium. X Ray Diffraction shows that the rutile structure remains the same of pure tin dioxide but with better crystallization. The titanium doping enhances the transmittance up to 83% and the conductivity about 1.4×102(Ω.cm)−1 approximately, with high figure of merit values about 7.64×10−3 Ω−1.these results are required specially for bio-sensors and optoelectronics

Comparison of SnO2-carbon nanotubes composite and the SnO2-carbon black mixture as an anode for Li-ion batteries

This article reports a comparative study on the electrochemical properties between SnO2-carbon nanotubes (CNTs) composite and SnO2-carbon black (CB) mixture. The SnO2-CNTs composite was directly synthesized by a sol-gel method with purified multi-walled carbon nanotubes and tin chloride. The SnO2-CB mixture was obtained by mixing carbon black with the previously prepared SnO2. XRD profiles of SnO2-CNTs and the obtained SnO2 have shown the pure tin dioxide phase for the composite and the mixture. TEM images confirmed that SnO2 nanoparticles with average particle size of 3-20 nm are deposited on the outer surface of carbon nanotubes, while the SnO2 obtained for the mixture indicate larger average particle size than that of in the SnO2-CNTs composite. These samples were used as anode materials for the lithium ion battery. The SnO2-CNTs composite showed an initial charge capacity of 810 mAg−1 which slightly reduced to 500 mAg−1 after 100 cycles. The SnO2-CB mixture had a smaller capacity, i.e., an initial charge capacity of 350 mAg−1, and decreased to 230 mAg−1 after 100 cycles. A reversible capacity at 0.2 Ag−1 was recovered for both samples after the cycling at different current densities, which implies excellent rate performance of the materials.

Detection of Carbon Monoxide in Humid Air with Double-Layer Structures Based on Semiconducting Metal Oxides and Silicalite

Double-layer structures based on gas-sensitive semiconducting metal oxides and silicalite-1 were tested in detection of carbon monoxide in humid air. Pure tin dioxide and that modified with antimony and palladium served as materials of the sensitive layer. Upon deposition of a silicalite-1 layer on SnO2 and SnO2/PdOx, the signal for CO in dry air at room measurement temperature (T = 25°C) grows, but an increase in the air humidity results in that the sensor sensitivity fully disappears. Raising the measurement temperature to 100°C makes weaker the adverse effect of the humidity. The double-layer structure containing the SnO2(Sb)/PdOx nanocomposite is characterized by the most stable sensor signal that is independent of the air humidity within the range RH = 4‒65%.

Characterization and Electrochemical Performance at High Discharge Rates of Tin Dioxide Thin Films Synthesized by Atomic Layer Deposition

In this study, thin films of tin dioxide have been synthesized on substrates of silicon and stainless steel by atomic layer deposition (ALD) with tetraethyl tin and by inductively coupled remote oxygen plasma as precursors. Studies of the surface morphology by scanning electron microscopy show a strong dependence on synthesis temperature. According to the x-ray photoelectron spectroscopy measurements, the samples contain tin in the oxidation state +4. The thickness of the thin films for electrochemical performance was approximately 80 nm. Electrochemical cycling in the voltage range of 0.01–0.8 V have shown that tin oxide has a stable discharge capacity of approximately 650 mAh/g during 400 charge/discharge cycles with an efficiency of approximately 99.5%. The decrease in capacity after 400 charge/discharge cycles was around 5–7%. Synthesized SnO2 thin films have fast kinetics of lithium ions intercalation and excellent discharge efficiency at high C-rates, up to 40C, with a small decrease in capacity of less than 20%. Specific capacity and cyclic stability of thin films of SnO2 synthesized by ALD exceed the values mentioned in the literature for pure tin dioxide thin films.

Compressibility and structural behavior of pure and Fe-doped SnO2 nanocrystals

We have performed high-pressure synchrotron X-ray diffraction experiments on nanoparticles of pure tin dioxide (particle size ∼30 nm) and 10 mol % Fe-doped tin dioxide (particle size ∼18 nm). The structural behavior of undoped tin dioxide nanoparticles has been studied up to 32 GPa, while the Fe-doped tin dioxide nanoparticles have been studied only up to 19 GPa. We have found that both samples present at ∼13 GPa a second-order structural phase transition from the ambient pressure tetragonal rutile-type structure (P42/mnm) to an orthorhombic CaCl2-type structure (space group Pnnm). No phase coexistence was observed for this transition. Additionally, pure SnO2 presents a phase transition to a cubic structure at ∼24 GPa. The evolution of the lattice parameters with pressure and the room-temperature equations of state are reported for the different phases. The reported results suggest that the partial substitution of Sn by Fe induces an enhancement of the bulk modulus of SnO2. Results are compared with previous studies on bulk and nanocrystalline SnO2. The effects of pressure on Sn-O bonds are also analyzed.

Microstructural study of nanocrystalline pure and doped tin dioxide to be used for resistive gas sensors

Nanocrystalline pure and doped SnO2 have been intensively studied for a long time to build resistive gas sensors. However, it is still useful to synthesize nanopowders with the smallest crystallite size to build devices. A modified gel-combustion method and a novel reactive oxidation process are proposed for nanopowders synthesis and results are compared. Materials have been characterized by XRD, Scherrer equation to evaluate the crystallite size; BET absorption to determine specific area and HRTEM to observe the crystallites (evaluating their mean size and distribution); defects and effect of calcination treatments are also considered. Previous studies have shown that if nano-SnO2 replaces the conventional microcrystalline-SnO2 to build resistive gas sensors, sensitivity increases (>30%) and the operation temperature considerably decreases.A heating and measuring system has been designed for achieving low power consumption and uses pulsed heating operation. This method of electrical control and measurement is operated intermittently, with “heating” and “readout” cycles (readout: signal of sensitive film).

Synthesis and characterization of low amount tin-doped ceria (Ce Sn1−O2−) for catalytic CO oxidation

Abstract A series of CeXSn1−XO2−δ oxides with low amount of tin (X ⩾ 0.8) have been synthesized by coprecipitation, and characterized by a sort of techniques. All the prepared oxides were in the range of mesoporous materials. It was found that the incorporation of tin prevented the ceria crystallites growth. The solubility limit for tin-doped ceria oxide was found to be 22 at.%, and partial segregation of tin dioxide was found for sample with X = 0.8 by XRD, Raman, DRS UV–vis and XPS techniques. The microstrain of the mixed oxides, associated with the lattice defects, increased with the tin content, which affects the reducibility and OSC, which were higher for mixed oxides in comparison than for pure ceria and tin dioxide. The incorporation of tin into the ceria lattice increased the total surface acidity. XPS analysis showed that both 4+ and 3+ oxidation states for Ce, and metallic tin together with oxidized tin were present in the mixed oxides, being Ce4+ and Sn4+/2+ species the most abundant in the surface. The prepared CeXSn1−XO2−δ mixed oxides showed to be very suitable as catalytic support for copper oxide in CO oxidation, especially for samples with X = 0.975 and 0.95.

Synthesis, structural and optical properties of Al doped SnO2 nanoparticles

Pure tin dioxide (SnO2) and Al doped SnO2 nanoparticles are prepared by co-precipitation method. Studies on structural and morphological properties are done by X-ray diffraction, field emission scanning electron microscopy and electron diffraction X-ray spectroscopy and optical properties by using UV–Visible spectroscopy in diffuse reflectance spectroscopy mode. Porosity is found to increase with Al doping when compared to pure SnO2. The band gap as well as Urbach energy increases with Al doping. Al doped SnO2 exhibits high porosity.

Tailoring nanomaterial products through electrode material and oxygen partial pressure in a mini-arc plasma reactor

Nanomaterials with controllable morphology and composition are synthesized by a simple one-step vapor condensation process using a mini-arc plasma source. Through systematic investigation of mini-arc reactor parameters, the roles of carrier gas, electrode material, and precursor on producing diverse nanomaterial products are revealed. Desired nanomaterial products, including tungsten oxide nanoparticles (NPs), tungsten oxide nanorods (NRs), tungsten oxide and tin oxide NP mixtures and pure tin dioxide NPs can thus be obtained by tailoring reaction conditions. The amount of oxygen in the reactor is critical to determining the final nanomaterial product. Without any precursor material present, a lower level of oxygen in the reactor favors the production of W18O49 NRs with tungsten as cathode, while a high level of oxygen produces more round WO3 NPs. With the presence of a precursor material, amorphous particles are favored with a high ratio of argon:oxygen. Oxygen is also found to affect tin oxide crystallization from its amorphous phase in the thermal annealing. Results from this study can be used for guiding gas phase nanomaterial synthesis in the future.

A novel chelating acid-assisted thermolysis procedure for preparation of tin oxide nanoparticles

Pure tin dioxide (SnO 2) nanoparticles were synthesized via thermolysis of tin phthalate and tin oxalate in the presence of oleic acid (OA) as solvent. Oleic acid (OA) was employed as an organic solvent, which can be applied to control particle growth and to stabilize the particles. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and photoluminescence (PL) spectroscopy. The orthorhombic phase SnO 2 nanoparticles with average size about 12 nm were synthesized through thermolysis of tin phthalate in the presence of oleic acid.

Crystallite growth kinetics of highly pure nanocrystalline tin dioxide: The effect of palladium doping

TXRD study together with BET, HRTEM and TEM techniques were performed to investigate the effect of Pd doping on crystallite growth kinetics of highly pure nanocrystalline SnO 2 during isothermal annealing at 873, 973 and 1073 K. Apparent activation energy for crystallite growth of blank as well as surface and bulk doped SnO 2 was estimated applying grain growth model with size-dependent impediment. Low activation energy for blank material (∼23 kJ mol −1) suggests that Sn self-diffusion on the reduced crystallite's surface is the most probable mechanism contributing to the growth process. Together with very low crystallite growth rate blank material demonstrates the highest agglomeration degree after annealing. Doping with Pd does not result in drag effect on crystallite boundary mobility. In contrary, it results in remarkable increase of crystallite growth rate together with an increase in the activation energy. In the case of bulk doped SnO 2 the phenomenon of crystallite coalescence was observed.

Synthesis and properties of pure and antimony-doped tin dioxide thin films fabricated by sol–gel technique on silicon wafer

High-quality antimony-doped tin dioxide (SnO 2:Sb) thin films with various concentrations of Sb have been prepared on Si (1 1 1) wafer by sol–gel technique. The microstructure, surface morphology, composition and optical properties of the films are characterized using X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and spectroscopic ellipsometry. It is found that the films are the dominant orientation of (1 0 1) with rutile structure of SnO 2, Sb dopant causes the peak positions in XRD patterns to shift slightly instead of introducing new phases, and the average grain size of the films is about 26 nm. Optical constant, refraction index n from 1.55 to 1.95 in the visible spectral region, was determined through multilayer analyses on their respective pseudo-dielectric functions. It is also found that the optical constants depend strongly on the layers of films, annealing temperature and the concentration of Sb dopant.