SnO2 Samples Research Articles

Unraveling Oxygen Vacancies Effect on Chemical Composition, Electronic Structure and Optical Properties of Eu Doped SnO2.

The influence of Eu doping (0.5, 1 and 2 mol.%) and annealing in an oxygen-deficient atmosphere on the structure and optical properties of SnO2 nanoparticles were investigated in relation to electronic structure. The X-ray diffraction (XRD) patterns revealed single-phase tetragonal rutile structure for both synthesized and annealed Eu-doped SnO2 samples, except for the annealed sample with 2 mol.% Eu. The results of X-ray photoelectron spectroscopy (XPS) emphasized that europium incorporated into the SnO2 host lattice with an oxidation state of 3+, which was accompanied by the formation of oxygen vacancies under cation substitution of tetravalent Sn. Moreover, XPS spectra showed the O/Sn ratio, which has been reduced under annealing for creating additional oxygen vacancies. The pulse cathodoluminescence (PCL) demonstrated the concentration dependence of Eu site symmetry. Combination of XRD, XPS and PCL revealed that Eu doping and following annealing induce strongly disordering of the SnO2 crystal lattice. Our findings provide new insight into the interaction of rare-earth metals (Eu) with host SnO2 matrix and new evidence for the importance of oxygen vacancies for optical and electronic structure formation.

CO2 detection using In and Ti doped SnO2 nanostructures: Comparative analysis of gas sensing properties

This research explores the gas-sensing characteristics of undoped SnO2, as well as indium (In:SnO2) and titanium (Ti:SnO2) doped SnO2 nanostructures, which were synthesized using a homogeneous precipitation technique. Structural analyses indicate the presence of a tetragonal rutile phase with a preferred orientation along the (110) plane, with both doped samples showing shifts towards higher angles. Raman spectroscopy confirms the vibrational modes associated with SnO2 in both the pure and In: SnO2 samples, while the Ti: SnO2 sample reveals vibrational modes corresponding to both SnO2 and TiO2. Fourier-transform infrared (FTIR) spectroscopy indicates shifts in the O-Sn-O and Sn-O bonds in the doped samples, suggesting the effects of doping. X-ray photoelectron spectroscopy (XPS) results imply a combination of SnO and SnO2 phases in the undoped SnO2, while In: SnO2 samples display In-O bonding and the presence of metallic indium, and Ti: SnO2 shows Ti-O bonding. Scanning electron microscopy (SEM) images show agglomerated particles in the pure and In-doped samples, whereas the Ti-doped samples exhibit a flake-like structure. Transmission electron microscopy (TEM) analysis verifies the integration of dopants into the SnO2 crystal lattice, with average crystallite sizes measured at 44.46 nm for undoped, 34.06 nm for In: SnO2, and 42.63 nm for Ti: SnO2. Gas-sensing experiments for CO2 detection reveal that In: SnO2 demonstrates the most significant sensing response. These results underscore the impact of doping on the structural, morphological, and gas-sensing attributes of SnO2 nanostructures, offering important insights for the advancement of efficient carbon dioxide sensors.

Study of an enhanced photocatalytic hybrid MnO2@SnO2 core-shell Z-scheme nano heterojunction for efficient H2 production

The usage of non-renewable carbon-base fuel energy have created multiple issues such as global warming, environmental degradations etc. Replacing these non-renewable sources of energy with renewable energy (photocatalytic H2 production) is a hot topic for researchers due to its sustainability and eco-friendliness. In this work MnO2, SnO2 and their nanocomposites have been synthesized through simple hydrothermal and co-precipitation methods. The purpose of such nanocomposite fabrication is to synthesize a suitable heterostructure for maximum solar energy harvesting in water splitting. All the prepared samples of pure MnO2, SnO2, and nanocomposites have been characterized through various techniques, which confirm the structure, functional groups, absorbance, morphology, elemental compositions, chemical compositions, and increase in photo-induced current as well as the photostability of such nanocomposites. The highest apparent quantum yield of the optimized MnO2@SnO2 (first time reported as photocatalyst for H2 production) were 21.7% at wavelength 420 nm, which is the highest ever reported for such (MnO2@SnO2) nanocomposite. The enhanced photocatalytic behavior for H2 production has been observed which is 3.67 times greater than pristine MnO2. Such an enhancement is due to the synergistic effect of SnO2 NPs decorated on the NTs of MnO2. The present work provides a novel approach to produce hydrogen with high performance as efficient solar harvesting.

Impact of calcined temperatures on the crystalline parameters, morphological, energy band gap, electrochemical, antimicrobial, antioxidant, and hemolysis behavior of nanocrystalline tin oxide

To construct a battery, the precipitation-synthesized SnO2 products at 450 °C and 650 °C were separately taken and mixed with graphite as the anode and PbO2,V2O5, and graphite materials as cathode materials to make the pellets and examine their open circuit voltage (OCV) values. The microstrain, lattice parameter, and crystallite size values of the above-mentioned tin oxide compounds were obtained through Rietveld refinement-MAUD fit analysis. The microstrain and lattice parameter values of tin oxide were significantly varied at a higher calcined temperature. Surface particle grain growth was increased with the increased calcined temperature from 450 to 650 °C as evidenced by FE-SEM study. Particle size distributions of SnO2 and polycrystalline behavior have been discussed with the aid of TEM analysis. From the UV–visible spectra, optical band gap (Eg) values reduced from 3.73 to 3.69 eV for the SnO2 products with an increase in calcined temperatures from 450 to 650 °C. The antimicrobial responses of the two different calcined SnO2 samples at 450 °C and 650 °C against two different bacterial pathogens (gram-positive-S. aureus and gram-negative-E.coli) were investigated. From the microbicidal assessment, a relatively higher diameter of the zone of inhibition (DZOI) of tin oxide at 650 °C samples was measured to be 19 ± 2 mm and 21 ± 2 mm for S. aureus and E. Coli than the DZOI of SnO2 at 450 °C samples (15 ± 1 mm for S. aureus and 18 ± 1 mm for E. coli. DPPH scavenging activity at 100 μg/ml shows that SnO₂ calcined at 450 °C achieves 68 ± 1 %, while SnO2 calcined at 650 °C exhibits a significantly higher activity of 86 ± 1 %. A slight increase in hemolysis was observed for SnO2 calcined at 650 °C, reaching 1.3 % at higher concentrations, but overall, hemolysis remained below 5 %, indicating high hemocompatibility.

Construction dual active sites on SnO2 via Fe doping for effective ciprofloxacin photodegradation

Adjusting the electronic structure via doping and enhancing the active sites of photocatalysts are proven strategies for improving the photodegradation of pollutants. However, the photodegradation mechanism involving doping elements and their impact on pollutant adsorption and activation at active sites remain unclear. In this study, Fe-doped SnO2 photocatalysts were synthesized using the hydrothermal method, featuring small particle sizes and highly active sites. It was found that doping SnO2 with 3 mol% Fe3+ significantly enhances its photocatalytic efficiency in degrading Ciprofloxacin, outperforming pure SnO2 by approximately 18.6 times. Spectroscopy methods, combined with density functional theory calculations, revealed that the presence of Lewis acid sites and oxygen vacancies serve as active sites in the Fe-doped SnO2 samples. Furthermore, a detailed photodegradation mechanism for Fe-doped SnO2 was proposed based on the band energy structure and analysis of free radical results. This research provides new insights into the mechanism of photocatalytic degradation of Ciprofloxacin by elucidating the interactions between the active sites of the photocatalyst and Ciprofloxacin molecules.

Gas sensing capabilities of sol–gel dip-coated pure SnO2 thin films for CO and C3H8 detection

This paper presents a comprehensive investigation to increase the gas sensing capability of pure tin oxide (SnO2) film coatings while ensuring non-contamination. The SnO2 thin-film coatings deposited on glass substrates were processed by homogeneous precipitation and sol–gel dip coating methods. Various characterization techniques, including X-ray diffraction, ultraviolet–visible spectroscopy (UV–Vis), and scanning electron microscopy were used to analyze the structural, optical, and morphological properties of the coatings. The prepared SnO2 coatings were tested using separately two different gases, carbon monoxide (CO) and propane (C3H8), to assess their gas sensing capabilities. The results show a significant influence of the multilayer coating of SnO2 on the sensing performance. Remarkably, the SnO2 sample with three layers exhibited a high sensitivity. By enhancing the gas sensing capabilities of tin oxide films through the dip coating technique, this study contributes to the advancement of gas sensing technologies.

Green-assisted synthesis of highly defective nanostructured Fe-doped SnO2: Magnetic and photocatalytic properties evaluation

Here we present a comprehensive characterization of the properties of undoped and Fe-doped SnO2 nanoparticles prepared with Syzygium cumini leaves extract. The phytochemicals present in the leaves extract act as cation chelating and capping of the nanoparticles. It is observed a relative high concentration of tin (up to 10 %) and oxygen (up to 5%) vacancies promoted by surface adsorbed OH− and by Fe-doping, respectively. The magnetic characterization reveals a ferromagnetic with a saturation monetization up to 20×10−3 emu/g for the higher defective and Fe-doped sample. This behavior associated mainly to tin vacancies for the undoped samples, and to the formation of bound magnetic polarons between the incorporated Fe and the oxygen vacancies for the doped samples. Oxygen vacancies and incorporated Fe improve the SnO2 photocatalytic efficiency in the visible range of the electromagnetic spectrum by decreasing the SnO2 effective bandgap from 3.6 eV for the undoped SnO2 sample to only 1.9 eV for the Fe-doped SnO2 sample, and by acting as electron-trapping centers increasing the system quantum efficiency. Due to the ferromagnetic behavior of the studied samples, it was also considered the effect of spin-dependent processes in the observed photocatalytic improvement. Our results highlight the key role of defect engineering strategies to optimize the physical and chemical properties of semiconductor oxides for application in the development of spintronic and quantum information devices, and in systems devoted to wastewater purification through advanced oxidation processes.

Oxygen Vacancy Mediation in SnO2 Electron Transport Layers Enables Efficient, Stable, and Scalable Perovskite Solar Cells.

Previous findings have suggested a close association between oxygen vacancies in SnO2 and charge carrier recombination as well as perovskite decomposition at the perovskite/SnO2 interface. Underlying the fundamental mechanism holds great significance in achieving a more favorable balance between the efficiency and stability. In this study, we prepared three SnO2 samples with different oxygen vacancy concentrations and observed that a low oxygen vacancy concentration is conducive to long-term device stability. Iodide ions were observed to easily diffuse into regions with high oxygen vacancies, thereby speeding up the deprotonation of FAI, as made evident by the detection of the decomposition product formamide. In contrast, a high oxygen vacancy concentration in SnO2 could prevent hole injection, leading to a decrease in interfacial recombination losses. To suppress this decomposition reaction and address the trade-off, we designed a bilayer SnO2 structure to ensure highly efficient carrier transport still while maintaining a chemically inert surface. As a result, an enhanced efficiency of 25.06% (certified at 24.55% with an active area of 0.09 cm2 under fast scan) was achieved, and the extended operational stability maintained 90% of their original efficiency (24.52%) after continuous operation for nearly 2000 h. Additionally, perovskite submodules with an active area of 14 cm2 were successfully assembled with a PCE of up to 22.96% (20.09% with an aperture area).

Highly Tuning of Sunlight-Photocatalytic Properties of SnO2 Nanocatalysts: Function of Gd/Fe Dopants

Gd/Fe-SnO2 nanopowders as novel photocatalysts for the active removal of Rose Bengal dye and methyl parathion pesticide were synthesized with a low-cost coprecipitation route. The X-ray diffraction analysis of SnO2, Sn0.96Gd0.02Fe0.02O2 and Sn0.94Gd0.02Fe0.04O2 nanopowders proved the formation of a tetragonal phase of tin oxide with average crystallite sizes in the range of 13–18 nm. The Fourier transform infrared (FTIR) spectra of all samples displayed the characteristic absorption bands of SnO2. The nanopowder of the pure SnO2 sample, as seen in its transmission electron microscope (TEM) image, contains spherical-like particles of variable sizes. The TEM images of the Sn0.96Gd0.02Fe0.02O2 and Sn0.94Gd0.02Fe0.04O2 powders revealed the synthesis of fine spherical nanoparticles. Based on the TEM images, the average particle size of the pure, (Gd, 2 wt% Fe) and (Gd, 4 wt% Fe) codoped SnO2 nanopowders was estimated to be 14, 10 and 12 nm, respectively. After the addition of (Gd, 2 wt% Fe) and (Gd, 4 wt% Fe) to the SnO2 structure, the band gap energy of SnO2 was reduced from 3.4 eV to 2.88 and 2.82 eV, respectively. Significantly, the Sn0.96Gd0.02Fe0.02O2 nanocatalyst exhibited a high removal efficiency of 98 and 96% for Rose Bengal dye and methyl parathion pesticide after activation by sunlight for 35 and 48 min, respectively. Furthermore, this catalyst has shown perfect mineralization as well as high stability properties for the treatment of Rose Bengal dye and methyl parathion pesticide. These results suggest the suitability of the Sn0.96Gd0.02Fe0.02O2 nanocatalyst for the treatment of agriculture and industrial effluent under sunlight light energy.

Layer-tunable synthesis of tetragonal Pr-doped SnO2 nanoplates for enhanced sensitive SO2 sensor

Nowadays SnO2 is widely used in manufacturing gas sensors for the detection of toxic and harmful gases such as SO2. However, SnO2 sensor still has the drawbacks of long recovery/response time and low response value. In this experiment, layer-tunable synthesis of tetragonal Pr-doped SnO2 nanoplates are prepared by a feasible hydrothermal method. Observation at SEM reveals that the layer number increases and the interlayer spacing reduces with the increase of doping ratio of Pr (1, 3, 5 mol%). The gas sensing performance show that the three layer tetragonal structure of 1 mol% Pr-doped SnO2 sample with the extended interlayer spacing exhibits outstanding gas sensing performance to 5 ppm SO2 gas at 300℃, including excellent gas response (Ra/Rg = 2.4), fast gas adsorption and desorption equilibrium (15 s/16 s). This work reveals the significance of the layer number and interlayer spacing on the gas sensing characteristics, and the strategy of Pr dopant will promote the widespread application of SnO2 nanomaterials in SO2 gas sensors to figure out severe environmental problems.

Intermediate tin oxide in stable core-shell structures by room temperature oxidation of cluster-assembled nanostructured Sn films

Room temperature oxidation of cluster-assembled nanostructured Sn films obtained by supersonic cluster beam deposition was investigated. Sn clusters smaller than about 10 nm are observed to be fully oxidized while in larger ones, as well as in Sn islands formed by clusters coalescence, completion of Cabrera-Mott process is prevented resulting in partial oxidation. Core-shell structures are therefore obtained, with shell thickness of about 4 nm. Core is composed by highly ordered, tetragonal β-tin, with micro-strain of 0.16 %, while shell is composed of tin oxides, where similar quantity of both Sn oxidation states Sn2+ and Sn4+ are observed, according to XPS. The presence in the samples of metallic tin, SnO, and SnO2 is confirmed by valence band photoelectron spectrum, whose components show edges at 0, 0.6, and 3.2 eV from Fermi level, respectively. Raman spectroscopy highlights the presence of Sn3O4 (short version of Sn2+2O2Sn4+O2), which confirms the spontaneous formation of this intermediate oxide. It is therefore proposed that an oxidation gradient Sn-SnO-Sn3O4-SnO2 characterizes core-shell system resulting from room temperature Cabrera-Mott oxidation of cluster-assembled nanostructured films.

Characterizations of Cr3+- doped SnO2 Powders Via a Hydrolysis Method

In this work, the effect of annealing temperature and Cr3+ concentration on the structural and optical properties of the SnO2 host crystals has been investigated. The Cr-doped SnO2 samples were synthesized by a simple hydrolysis method, using SnCl4.5H2O as the host precursor and CrCl3.6H2O as the source of dopant. X-ray diffraction and Raman scattering spectra analysis revealed a tetragonal rutile structure of Cr3+-doped SnO2 samples. The Cr3+ concentration and annealing temperature have no influence on the lattice parameters of the SnO2 crystals, whereas affected the appearance and intensity of the Raman modes. The optical properties of the synthesized samples were explored by photoluminescence (PL) and photoluminescence excitation (PLE) analysis. Interestingly, besides the emission peaks related to the SnO2, emission transitions within Cr3+ ions in the octahedral field of SnO2 were observed.

Synthesis and characterization of transition metals (Mn, Fe, Co, Ni) doped tin oxide for magnetic and antimicrobial studies

Dilute magnetic semiconductor oxides (DMSOs) are attractive prospects for improved charge and spin degrees of freedom control. The current research presents an overview of the structural analysis and magnetic characteristics of DMSOs based on binary metal oxide nanomaterials with various ferromagnetic or paramagnetic dopants, such as Mn, Fe, Co, and Ni, which display increased ferromagnetic behaviour at ambient temperature. The co-precipitation approach was used to create nanoparticle samples of pure SnO2, Sn0.97Mn0.03O2, Sn0.97Fe0.03O2, Sn0.97Co0.03O2, and Sn0.97Ni0.03O2. The emission spectra for the high, wide emission band are 366 nm and 655 nm. Room temperature magnetic hysteresis loops for Mn, Fe, and Ni-doped SnO2 indicate ferromagnetic behaviour when compared to pure and Co-doped SnO2, with Sn0.97Mn0.03O2, Sn0.97Fe0.07O2, and Sn0.97Ni0.03O2 samples exhibiting increased coercivity and retentivity. The antibacterial activity of pure SnO2, Sn0.97Mn0.03O2, Sn0.97Fe0.03O2, Sn0.97Co0.03O2, and Sn0.97Ni0.03O2 nanoparticles was determined.

Deposition Temperature as a Crucial Process Parameter in Tuning the CO2 Sensing Properties of Spary-Pyrolyzed SnO2 Thin Film

SnO2 thin films are deposited on 76 × 26 × 12 mm glass substrates by spray pyrolysis technique from an aqueous solution of SnCl4.5H2O at various deposition temperatures in the range 250 °C–330 °C and their Carbon Dioxide (CO2) sensing properties are studied. Crystallographic measurements performed on the samples reveal the tetragonal cassiterite structure with a P42/mnm space group. The micro-strain, crystallite size and the texture of prominent planes vary with deposition temperature. The effect of deposition temperature on the surface topography is closely examined by Field Emission Scanning Electron Microscopy (FESEM). The CO2 sensing properties reveals that the sample prepared at 310 °C shows better response to CO2. The presence of tin interstitials oxygen vacancies and excitons is confirmed by PL spectra. Raman spectra depict the formation of sub-stoichiometric phases in the sample. It is found that the deposition temperature is crucial in controlling the dislocations, surface defects, and crystalline orientation that play an important role in enhancing the CO2 sensing performance. To investigate the conduction mechanism prevailing in the sample, AC conductivity measurements of the SnO2 thin films are carried out using Agilent 4294 A precision impedance analyzer and the results are correlated with their CO2 sensing properties.

Support of Cd doping in SnO2 nanoparticles to enhance its thermoelectric parameters

In the present study we have successfully synthesized undoped and Cd doped SnO2 nanoparticles using the Sol-gel method with different concentrations of Cd solutions, and Seebeck coefficient and electrical conductivity have been reported at various temperatures. The structural, morphological, thermoelectric and electrical properties of undoped and doped samples were by XRD, scanning electron microscopy, Raman spectroscopy, Seebeck effect and two point probe electrical measurement. XRD show the rutile tetragonal structure and the enhanced particle size in the range of 18.12 nm to 25.08 nm, and Raman active mode at 479cm-1 , 632cm-1 and 775cm-1 were measured by Raman spectroscopy. Morphology of the nanoparticles by using Scanning electron microscopy have revealed the random spherical shape and cluster formation of these nanoparticles. The maximum value of seebeck coefficient, electrical conductivity and power factor for 6% doped SnO2 samples were found to be -297.92μV/°C, 33.33Ω-1 m-1 and 0.129117 x 106 Wm-1 /°C2 , respectively. These results reveal that the Cd doped tin dioxide (SnO2) nanoparticles can be used as a good candidate for thermoelectric applications.

Investigation on Sb-doped SnO2 as an efficient sensor for the detection of formaldehyde

The applicability of antimony-doped tin dioxide (Sb-doped SnO2) as a very precise sensor for detecting formaldehyde (HCHO) gas is investigated in this study. The sol-gel method was used to prepare pure SnO2 and Sb-doped SnO2 nanostructures, which resulted in better structural and morphological properties. The prepared samples were analyzed using several characterization techniques, including X-ray diffractometer (XRD), field emission scanning electron microscopy (FE-SEM), Fourier-transform infrared spectroscopy (FTIR), UV-Vis spectroscopy and X-ray photoelectron spectroscopy (XPS). A structural investigation indicated the presence of a tetragonal SnO2 phase with a clear preference for the (110) orientation. Furthermore, the crystallite size reduced as the quantity of Sb doping rose. According to FE-SEM analysis, both the undoped (SnO2) and Sb-doped SnO2 samples had polyhedral structures. FTIR analysis verified the presence of organic functional groups in the prepared powder samples. The optical band gap (Eg) values decreased with an increasing concentration of Sb doping in the SnO2 nanostructures. XPS was used to determine the chemical elements of the prepared powder samples. In the gas sensing study, those based on 8 wt% Sb-doped SnO2 (referred to as ATO-8) outperformed the others. At room temperature, the ATO-8 sample demonstrated stronger sensor response, faster response and recovery durations (98 s/74 s), and linear behavior. These enhancements can be attributable to an increase in adsorbed oxygen species caused by Sb doping, highlighting ATO-8's potential as a substance for detecting HCHO. This study emphasizes the potential of ATO-8 as a significant resource for practical use in the detection of HCHO, with benefits such as improved indoor air quality, increased industrial safety, and advancements in environmental monitoring.

Highly Selective and Fast Response/Recovery Cataluminescence Sensor Based on SnO2 for H2S Detection.

In the present work, three kinds of nanosized SnO2 samples were successfully synthesized via a hydrothermal method with subsequent calcination at temperatures of 500 °C, 600 °C, and 700 °C. The morphology and structure of the as-prepared samples were characterized using X-ray diffraction, transmission electron microscopy, selected area electron diffraction, Brunauer-Emmett-Teller analysis, and X-ray photoelectron spectroscopy. The results clearly indicated that the SnO2 sample calcined at 600 °C had a higher amount of chemisorbed oxygen than the SnO2 samples calcined at 500 °C and 700 °C. Gas sensing investigations revealed that the cataluminescence (CTL) sensors based on the three SnO2 samples all exhibited high selectivity toward H2S, but the sensor based on SnO2-600 °C exhibited the highest response under the same conditions. At an operating temperature of 210 °C, the SnO2-600 °C sensor showed a good linear response to H2S in the concentration range of 20-420 ppm, with a detection limit of 8 ppm. The response and recovery times were 3.5 s/1.5 s for H2S gas within the linear range. The study on the sensing mechanism indicated that H2S was oxidized into excited states of SO2 by chemisorbed oxygen on the SnO2 surface, which was mainly responsible for CTL emission. The chemisorbed oxygen played an important role in the oxidation of H2S, and, as such, the reason for the SnO2-600 °C sensor showing the highest response could be ascribed to the highest amount of chemisorbed oxygen on its surface. The proposed SnO2-based gas sensor has great potential for the rapid monitoring of H2S.

Impact of air exposure on growth rate and electrical properties of SnO2 thin films by atmospheric pressure spatial atomic layer deposition

SnO2 thin film is one of the most studied transparent conductive materials that can be deposited using vacuum-free techniques such as atmospheric pressure spatial atomic layer deposition (AP-SALD). This work studies SnO2 thin films prepared from tin(II) acetylacetonate and water vapor, with a particular focus on the impact of air exposure during the AP-SALD process on the growth rate and electrical properties of the films. In-situ resistance measurements and ex-situ Hall effect characterization demonstrated that longer exposure time of the growing film surface to the open air (t air) at 240 °C led to conductivity degradation, while the film thickness decreases. The theoretical calculations show that −OH and (oxygen molecule adsorbed on the five-coordinated Sn atom, also called O2 dimer) are the two most stable surface structures. The formation of is shown as the most thermodynamically favorable oxygen-related species on SnO2(110) surface formed when the film is exposed to the open air, giving rise to both the decrease of film thickness (associated with the desorption of −OH surface groups) and the increase of film resistivity versus t air. The optimized polycrystalline SnO2 sample demonstrated relatively good electrical performance, including an electrical resistivity of 9.3 × 10−3 Ω.cm, carrier density of 9.2 × 1019 cm−3, and Hall mobility of 7.3 cm2 V−1 s−1 at a growth temperature as low as 240 °C. Our findings reveal the critical impact of processing in the open air on the electrical conductivity of the obtained SnO2 films by AP-SALD coating technology.

Effect of Sb Doping on Structure and Humidity Sensing Properties of SnO2 Synthesized by Hydrothermal Method

AbstractThe tetragonal rutile Sb doped Sn O2 (0, 0.5, 1 at.%) is successfully synthesized by hydrothermal method. The XRD analysis shows that the average crystallite size of SnO2 decreases from 29.59 to 20.53 nm with the increase of the doping concentration. SEM images depict the spherical grain morphology of the SnO2 sample. With the increase of the doping ratio, the optical bandgap value of the SnO2 samples increases from 3.6 to 3.86 eV and then decreases to 3.47 eV, showing a trend of first increasing and then decreasing. XPS results indicate that oxygen vacancy defects and substitutional defects(SbSn)are formed into the SnO2 lattice, which changes the electronic effect of Sn element to tune the oxygen vacancy concentration. The humidity‐sensitive testing data shows that 1 at.% Sb‐doped SnO2 humidity sensor presented excellent sensitivity and linearity at a working frequency of 100 Hz as compared to the pure SnO2 sample.

Isobutanol gas sensor based on Fe2O3–SnO2 heterostructure nanostructure

The rough surface Fe2O3–SnO2 composite nanorod material was prepared by electrostatic spinning. The morphology and nanostructure of Fe2O3–SnO2 composite nanorods were characterized by scanning electron microscopy SEM, nitrogen physical adsorption and X-ray diffraction. Through the analysis of the test results, it can be shown that the Fe2O3–SnO2 nanorod samples prepared in this experiment have the advantages of high purity, good crystallinity and large specific surface area. The specific surface area of the sample obtained from the test is 19.27 m2/g. According to the gas sensitivity test results of Fe2O3–SnO2 nanorods, it can be seen that Fe2O3–SnO2 samples have high responsiveness and excellent gas sensitivity selectivity. Various gases were tested in this experiment, and it was found that the sensor has good gas selectivity to isobutanol. At 310 °C, the sensor's response to 100 ppm isobutanol reached 13. This experiment not only prepared Fe2O3–SnO2 nanorod sensor with good isobutanol gas sensitivity. And it realized the accurate measurement of continuous isobutanol concentration. In addition, the gas sensitivity mechanism of Fe2O3–SnO2 nanomaterials was discussed.