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A data-fitting method based on the whale optimization algorithm (WOA) is proposed to determine the thickness and refractive index of films measured by spectroscopic ellipsometry (SE). To demonstrate this method, tin oxide (SnO2) films with transparent wavelength coverage (400–800 nm) are evaluated. The comparative analysis indicates that Psi and Delta parameter curves based on WOA fitting align more closely with those obtained through experiments. Furthermore, the thickness and refractive index of films obtained by WOA are in nearly agreement with the results from the well-known Levenberg–Marquardt (LM) algorithm. This validation confirms that it has great potential in the determination of film parameters in ellipsometry data fitting. [ABSTRACT FROM AUTHOR]

To reduce surface defects and tune mismatched energy levels between the tin oxide (SnO2) electron transport layer (ETL) and perovskite absorber, a mixture of urea and potassium acetate (U‐PA) is firstly utilized as a healing agent. The perovskite film deposited on the SnO2/U‐PA layer exhibits enlarged grains and shortened carrier lifetime compared to that on the pristine SnO2. The U‐PA treatment not only ameliorates the photocurrent but also adjusts interfacial energy level alignment, thereby reducing the energy barrier and augmenting open‐circuit voltage (VOC) of the photovoltaic devices. The device based on the SnO2/U‐PA ETL leads to the best conversion efficiency breakthrough of 19.24% and a high VOC of 1084.5 mV, which are much higher than those of the controlled device. Moreover, the unencapsulated device retains 70% of its initial efficiency after 800 h storage. The experimental results provide a facile and inexpensive guidance toward sustainable green energy production. [ABSTRACT FROM AUTHOR]

The electronic nose is an increasingly useful tool in many fields and applications. Our thermal electronic nose approach, based on nanostructured metal oxide chemiresistors in a thermal gradient, has the advantage of being tiny and therefore integrable in portable and wearable devices. Obviously, a wise choice of the nanomaterial is crucial for the device's performance and should therefore be carefully considered. Here we show how the addition of different amounts of Au (between 1 and 5 wt%) on Cu2O–SnO2 nanospheres affects the thermal electronic nose performance. Interestingly, the best performance is not achieved with the material offering the highest intrinsic selectivity. This confirms the importance of specific studies, since the performance of chemoresistive gas sensors does not linearly affect the performance of the electronic nose. By optimizing the amount of Au, the device achieved a perfect classification of the tested gases (acetone, ethanol, and toluene) and a good concentration estimation (with a mean absolute percentage error around 16%). These performances, combined with potentially smaller dimensions of less than 0.5 mm2, make this thermal electronic nose an ideal candidate for numerous applications, such as in the agri-food, environmental, and biomedical sectors. [ABSTRACT FROM AUTHOR]

This research explores the gas-sensing characteristics of undoped SnO 2 , as well as indium (In:SnO 2) and titanium (Ti:SnO 2) doped SnO 2 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 SnO 2 in both the pure and In: SnO 2 samples, while the Ti: SnO 2 sample reveals vibrational modes corresponding to both SnO 2 and TiO 2. 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 SnO 2 phases in the undoped SnO 2 , while In: SnO 2 samples display In-O bonding and the presence of metallic indium, and Ti: SnO 2 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 SnO 2 crystal lattice, with average crystallite sizes measured at 44.46 nm for undoped, 34.06 nm for In: SnO 2 , and 42.63 nm for Ti: SnO 2. Gas-sensing experiments for CO 2 detection reveal that In: SnO 2 demonstrates the most significant sensing response. These results underscore the impact of doping on the structural, morphological, and gas-sensing attributes of SnO 2 nanostructures, offering important insights for the advancement of efficient carbon dioxide sensors. [ABSTRACT FROM AUTHOR]

This study explores the surface chemistry and electrical responses of ultra-high-sensitivity SnO2 MEMS arrays to enable a novel sequential detection methodology for detecting nitrogen dioxide (NO2) and ethanol (C2H5OH) as a route to achieve selective gas sensing in electronic nose (E-nose) applications. Utilizing tin oxide (SnO2) thin films deposited via atomic layer deposition (ALD), the array achieves the lowest reported detection limits of 8 parts per billion (ppb) for NO2. The research delves into the detection mechanisms of NO2 and C2H5OH, both individually and in subsequent exposures, assessing the sensor's dynamic response across various operating temperatures. It demonstrates rapid response and recovery times, with averages of 48 s and 277 s for NO2 and 40 and 48 for C2H5OH. Understanding the role of individual gases on the SnO2 surface chemistry is paramount in discerning subsequent gas exposure behavior. The oxidizing behavior of C2H5OH following NO2 exposure is attributed to interactions between NO2 and oxygen vacancies on the SnO2 surface, which leads to the formation of nitrate or nitrite species. These species subsequently influence interactions with C2H5OH, inducing oxidizing properties, and need to be carefully considered. Principal component analysis (PCA) was used to further improve the sensor's capability to precisely identify and quantify gas mixtures, improving its applicability for real-time monitoring in complex scenarios. [ABSTRACT FROM AUTHOR]

Biochar derived from biomass resources as a carrier to load SnO2 for electroreduction of CO2 not only can benefit carbon emissions, but it also can achieve waste utilization. However, the weak CO2 mass transfer and conductivity ability of SnO2/biochar limits its applications to such eCO2RR processes. This study focused on modifying SnO2/biochar with amino groups and investigated the effects of positioning of amino groups on the catalyst’s physicochemical properties and electrocatalytic behaviors. Elemental analysis revealed that anchoring amino groups on biochar (SnO2/C-NHx) is advantageous for increasing amounts of amino groups attached, thereby enhancing biochar adsorption energy and subsequently increasing the loading of Sn. The CO2 adsorption curve indicated that amino groups anchored on biochar facilitate CO2 adsorption due to high specific surface area of biochar. X-ray photoelectron spectroscopy showed that amino groups anchored on SnO2 (NHx-SnO2/C) resulted in highly electron-rich centers on Sn, which promoted electron transfer between the catalyst and CO2. Electrochemical tests demonstrated the improved performance of amino-modified SnO2/biochar. SnO2/C-NHx exhibited enhanced Faraday efficiency, whereas NHx-SnO2/C showed higher current density. The disparity in electrochemical performance can be mainly attributed to the different selectivity towards rate-controlling steps of electron transfer and mass transfer induced by the various positions of amino groups anchoring.

The study focuses on creating new boro-silicate glasses doped with SnO2 for radiation shielding. It examines how substituting Na2O with SnO2 affects their structural, optical, and shielding properties. Density increases from 2.406 to 2.488 g/cm³ with rising SnO2, measured via the Archimedes Method. The examination for the glassy phase was performed using the XRD diffractometer. UV/Vis spectrophotometer analysis reveals reduced refractive index (2.412–1.976) and increased optical absorption-band gap (direct: 3.648–5.662 eV; indirect: 2.994–5.163 eV) with SnO2 concentrations of 0–9 mol.%). The effectiveness of the radiation shielding was assessed over the 0.059–1.408 MeV gamma-ray energy interval. The analysis demonstrates that when the concentration of SnO2 increases, the synthesized glasses' linear attenuation coefficient improves. As the SnO2 content was raised between 0 and 9 mol%, the linear attenuation coefficient rose between 0.489 and 2.892 cm−1 (at energy of 0.059 MeV) and between 0.126 and 0.128 cm−1 (at energy of 1.408 MeV), respectively. As the SnO2 content was raised between 0 and 9 mol%.

In this work, Tin oxide SnO2 hybrid structures were deposited on porous silicon substrates via spray pyrolysis method. The impact of the current density changes ranging from 5-15 mA/cm² with HF concentration of 18% was investigated at fixed substrate temperature of 250Co. The XRD analysis for nanostructures revealed the presence of tetragonal structure of SnO2. The Scanning electron Microscope (SEM) images showed the sponge-like structure of PSi with grooves and cavities following the deposition of SnO2 on the substrate. It can be seen, the grain diameter arrangement of the SnO2 was found to be in the range from 42-64 nm. The I-V characteristics showed that the resistance raises with the current density of the SnO2/porous silicon. The optical results refers that the absorption of SnO2 nanostructure increases with the number of spraying times for values of (10,15 and 20) respectively. Moreover, the results also revealed a degradation of the energy gap from 3.3 to 2.82eV at the same spraying values. The higher sensitivity was found around 49.35% at etching current density of 15mA/cm². The structure quality of the SnO2/PSi provides the possibility of using such structures in the high-quality sensors. [ABSTRACT FROM AUTHOR]

This study focuses on the teaching of electron transport layer materials within the Traditional Energy and New Energy curriculum, using perovskite solar cells as a starting point. It integrates the cutting-edge research on chemical bath deposition (CBD) of tin oxide (SnO2) electron transport layers into teaching practice. The study employs scanning electron microscopy (SEM), X-ray diffraction (XRD) and photoluminescence spectroscopy (PL) to characterize the SnO2 thin films prepared by CBD. It then applies these films to fabricate perovskite solar cells, evaluating their impact on device performance. The results show that compared to SnO2 thin films prepared by the traditional spin-coating method, those prepared by CBD are more uniform and denser, exhibit better crystallinity and higher electron extraction capability, ultimately achieving higher device efficiency. This research constructs a “Theory-Practice-Inquiry-Innovation” teaching model. By designing a teaching experiment on CBD of SnO2 electron transport layers, it effectively enhances students' learning interest, deepens their understanding of theoretical knowledge and stimulates their enthusiasm for exploring the field of new energy. This research provides a new approach for experimental teaching reform in universities and holds significant importance for cultivating new energy talents with practical skills and an innovative spirit. [ABSTRACT FROM AUTHOR]

Improving the gas‐sensing properties of sensors is important for the detection of ultralow‐concentration gases. As sensor signals are generated from the reactions on the surface of the sensor material, improving the surface structure of the sensor material can enhance the sensing properties. In this study, nanosheet‐type tin oxide with a metastable (101) crystal facet surface was used as the gas sensor material. To enhance the sensing properties, crystal facet‐controlled cerium oxide with superior oxygen storage capacity at moderate temperatures was decorated on the surface of the nanosheet‐type tin oxide material. An investigation of the sensor properties revealed that the decorated sensor exhibited improved gas selectivity and enhanced sensitivity to all tested gases. Prior to decoration, selectivity was observed for acetone and ethanol, whereas the decorated sensor exhibited high selectivity for acetaldehyde. The limits of detection of the decorated sensors were 245, 459, and 934 ppt for acetone, ethanol, and acetaldehyde, respectively. Thus, the proposed material can effectively enhance the sensing of extremely low‐concentration gases. [ABSTRACT FROM AUTHOR]

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Biochar derived from biomass resources as a carrier to load SnO2 for electroreduction of CO2 not only can benefit carbon emissions, but it also can achieve waste utilization. However, the weak CO2 mass transfer and conductivity ability of SnO2/biochar limits its applications to such eCO2RR processes. This study focused on modifying SnO2/biochar with amino groups and investigated the effects of positioning of amino groups on the catalyst's physicochemical properties and electrocatalytic behaviors. Elemental analysis revealed that anchoring amino groups on biochar (SnO2/C-NHx) is advantageous for increasing amounts of amino groups attached, thereby enhancing biochar adsorption energy and subsequently increasing the loading of Sn. The CO2 adsorption curve indicated that amino groups anchored on biochar facilitate CO2 adsorption due to high specific surface area of biochar. X-ray photoelectron spectroscopy showed that amino groups anchored on SnO2 (NHx-SnO2/C) resulted in highly electron-rich centers on Sn, which promoted electron transfer between the catalyst and CO2. Electrochemical tests demonstrated the improved performance of amino-modified SnO2/biochar. SnO2/C-NHx exhibited enhanced Faraday efficiency, whereas NHx-SnO2/C showed higher current density. The disparity in electrochemical performance can be mainly attributed to the different selectivity towards rate-controlling steps of electron transfer and mass transfer induced by the various positions of amino groups anchoring. [ABSTRACT FROM AUTHOR]

Polycrystalline SnO2-HfO2 nanolaminated thin films were grown by atomic layer deposition (ALD) on SiO2/Si(100) and TiN substrates at 300 °C. The samples, when evaluated electrically, exhibited bipolar resistive switching. The sample object with a stacked oxide layer structure of SnO2 | HfO2 | SnO2 | HfO2 additionally exhibited bidirectional threshold resistive switching properties. The sample with an oxide layer structure of HfO2 | SnO2 | HfO2 displayed bipolar resistive switching with a ratio of high and low resistance states of three orders of magnitude. Endurance tests revealed distinguishable differences between low and high resistance states after 2500 switching cycles. [ABSTRACT FROM AUTHOR]

To reduce surface defects and tune mismatched energy levels between the tin oxide (SnO2) electron transport layer (ETL) and perovskite absorber, a mixture of urea and potassium acetate (U‐PA) is firstly utilized as a healing agent. The perovskite film deposited on the SnO2/U‐PA layer exhibits enlarged grains and shortened carrier lifetime compared to that on the pristine SnO2. The U‐PA treatment not only ameliorates the photocurrent but also adjusts interfacial energy level alignment, thereby reducing the energy barrier and augmenting open‐circuit voltage (VOC) of the photovoltaic devices. The device based on the SnO2/U‐PA ETL leads to the best conversion efficiency breakthrough of 19.24% and a high VOC of 1084.5 mV, which are much higher than those of the controlled device. Moreover, the unencapsulated device retains 70% of its initial efficiency after 800 h storage. The experimental results provide a facile and inexpensive guidance toward sustainable green energy production.

Perovskite solar cells (PSCs) have demonstrated remarkable increase in their photovoltaic efficiencies over the past several years. Charge carrier properties including charge selectivity, extraction, and transport play key roles in device performances. Therefore, a comprehensive insight into the charge carrier dynamics and mobility within the bulk materials and at the interface is of great importance for the future development of this cutting‐edge technology. This review discusses the recent advances that have been made in SnO2 electron‐transporting layers and their limitations, followed by outlining the key development of novel strategies in improving SnO2 films through surface defect engineering, interface modification, and doping approaches. In addition, the recent developments are highlighted for identifying the origin of defect and trap center, and promoting SnO2 electron extraction and transporting capacity in PSCs. Importantly, the novel approaches are also discussed for studying photogenerated charge carrier dynamics of the devices. In conclusion, the own prospectives and outlooks are presented for the development of SnO2‐based PSCs, with a particular focus on addressing current difficulties in SnO2 and providing in‐depth understanding on the relationships between materials and devices.

Several thin film deposition techniques for oxide semiconducting materials have been developed. In this study, we employed an innovative technique known as chemical wet and dry (CWD) technique to deposit undoped SnO2 thin films on soda lime glass (SLG) and quartz substrates. This approach is an upgraded variant of the dip-coating process, involving controlled substrate withdrawal and in situ annealing in an inert gas atmosphere, ensuring uniform thickness control and contamination-free coating. The presence of a well-made undoped SnO2 thin film on SLG and quartz substrates was confirmed using grazing incidence x-ray diffraction (GIXRD). The films exhibit a mixed state of crystalline and amorphous nature, characterized by the presence of broad, strong peaks, suggesting Debye–Scherrer broadening. Furthermore, field emission scanning electron microscopy (FE-SEM) examinations showed an even distribution of particles on the film's surface, with particle sizes measuring between 10.58 nm and 9.17 nm. Fourier transform infrared (FT-IR) spectroscopy was utilized to detect functional groups within the film. This determination was substantiated by energy-dispersive x-ray spectroscopy (EDAX) analysis, confirming the film's composition. Optical investigations revealed that the films deposited on both SLG and quartz substrates possess remarkable transparency, exceeding 70% in the visible spectrum. The bandgap values range from 3.05 eV to 3.02 eV for SnO2 thin films deposited on SLG and quartz substrates, respectively. The variations in Hall mobilities, attributed to the impact of grain size, have been recognized, confirming the material's n-type characteristics as confirmed by Hall effect assessments. These prepared samples show promising prospects for use in forthcoming transparent conductive and optoelectronic devices, based on the aforementioned data and discoveries. [ABSTRACT FROM AUTHOR]

The effects of Au addition on the acetone response of Cu2O-added porous SnO2 (pr-Cu2O-SnO2) powders, which were synthesized by ultrasonic spray pyrolysis employing polymethyl methacrylate microspheres as a template, were investigated in this study. The 3.0 wt% Au-added pr-Cu2O-SnO2 sensor showed the largest acetone response among all sensors. In addition, the magnitude of the acetone response was much larger than those of the ethanol and toluene responses. The catalytic activities of these gases over Au-added pr-Cu2O-SnO2 powders were also examined to clarify the key factors affecting their acetone-sensing properties. The Au addition increased the complete oxidation activity of all gases, and the complete oxidation activity of acetone was much higher than those of ethanol and toluene. These results indicate that the oxidation behavior during the gas-diffusion process in the sensitive Au-added pr-Cu2O-SnO2 layer of the sensors is quite important in enhancing the acetone-sensing properties. [ABSTRACT FROM AUTHOR]

This research enhances ethanol sensing with Fe-doped tetragonal SnO2 films on glass, improving gas sensor reliability and sensitivity. The primary objective was to improve the sensitivity and operational efficiency of SnO2 sensors through Fe doping. The SnO2 sensors were synthesized using a flexible and adaptable method that allows for precise doping control, with energy-dispersive X-ray spectroscopy (EDX) confirming homogeneous Fe distribution within the SnO2 matrix. A morphological analysis showed a surface structure ideal for gas sensing. The results demonstrated significant improvement in ethanol response (1 to 20 ppm) and lower temperatures compared to undoped SnO2 sensors. The Fe-doped sensors exhibited higher sensitivity, enabling the detection of low ethanol concentrations and showing rapid response and recovery times. These findings suggest that Fe doping enhances the interaction between ethanol molecules and the sensor surface, improving performance. A mathematical model based on diffusion in porous media was employed to further analyze and optimize sensor performance. The model considers the diffusion of ethanol molecules through the porous SnO2 matrix, considering factors such as surface morphology and doping concentration. Additionally, the choice of electrode material plays a crucial role in extending the sensor's lifespan, highlighting the importance of material selection in sensor design. [ABSTRACT FROM AUTHOR]

Efficient inverted perovskite light‐emitting diodes (PeLEDs) are demonstrated by the introduction of tetraethyl orthosilicate (TEOS)‐incorporated tin oxide (SnO2) interlayer between the SnO2 electron injection layer and the perovskite emission layer. The TEOS incorporation into the SnO2 solution spontaneously converts it to a SiO2–SnO2 composite colloidal solution with a wide band gap, thermal stability, transparency, and chemical stability toward perovskite. The TEOS‐incorporated SnO2 interlayer effectively restricts the charge transfer from perovskite into SnO2 and promotes electron injection from SnO2 into perovskite due to the shift toward favorable energy band alignment. In addition, the TEOS‐treated interlayer balances the electron injection rate and the hole injection rate, thereby facilitating radiative recombination of the charge carriers injected into perovskite. As a result, the inverted PeLEDs exhibit significantly improved performance of 33 996 cd m−2 luminance, 9.99% of external quantum efficiency, and 44.83 cd A−1 of current efficiency. [ABSTRACT FROM AUTHOR]

The development of advanced tin and niobium bimetallic composite electrode materials is crucial for enhancing the performance of supercapacitors. In this paper, we present a novel bimetallic composite material consisting of zero-dimensional spherical-like SnNb2O6 nanocomposites synthesized through the reaction of tin oxide (SnO2) and niobium pentoxide (Nb2O5) precursors, alongside comparative materials. The morphology of the spherical agglomerates comprising Sn/Nb oxide particles that were nucleated on the SnNb2O6 surface was characterized using field emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HR-TEM). The as-prepared heterostructures of the SnNb2O6 composites were analyzed for elemental composition, including Sn3d, Nb3d, and O1s; moreover, chemical oxidative state analysis was performed through X-ray photoelectron spectroscopy (XPS). Additionally, cyclic voltammetry curves exhibited pseudocapacitive redox behavior for the SnNb2O6 composites, while the galvanostatic charge-discharge (GCD) performance demonstrated a maximum specific capacitance of 294.8 F/g at 1 A/g. Moreover, SnNb2O6 composite electrodes demonstrated rapid charge–discharge kinetics and excellent cycling stability, with a capacitance retention of 95.7% over 10,000 cycles. This study elucidated the synthesis of tin–niobium oxide-based composites, demonstrating their potential for high-performance supercapacitors. [ABSTRACT FROM AUTHOR]

Recent urbanization and environmental problems urge for networks of sensors that can monitor air quality. Small, inexpensive, and smart sensors are one of the key components enabling the realization of such networks. Chemoresistive sensors are the ideal candidate, but they greatly lack selectivity, and for this reason, they are usually combined in arrays to create electronic noses, whose dimensions, however, make them not miniaturizable and cannot be integrated into portable devices. To overcome this inconvenience, we present a thermal electronic nose consisting of identical resistive sensors working at different temperatures so that the whole device is simple to make and tiny. The device contains two sensor arrays based on tin oxide nanowires decorated with Ag and Pt nanoparticles, respectively. The five sensors in each array are identical, but their response is differentiated by different temperatures locally generated by an on-chip integrated heater. This innovative approach allows the tiny array of five sensors together with the integrated heater to occupy only approximately 50 × 200 μm2 and consume only 120 μW. The tiny and portable device can estimate the concentration of H2 and NH3 in a mixture with a root mean square error of 6.1 ppm and 13.3 ppm, respectively, and it still works well after two months. The performance analysis of the double partial least squares regression used for concentration estimation also allows for feedback on which sensors are the most sensitive to which gas so that the electronic nose can be engineered for specific applications using the most suitable sensors. The size of the thermal electronic nose allows it to be integrated into portable and wearable devices, and its performance makes it suitable for any gas detection application. For example, a smartphone with an integrated sensor could carry out breath analysis and act as medical pre-screening or be used to evaluate the freshness of agri-food products in a rapid and non-invasive way.

Line pattern replication process through nanoimprint lithography (NIL) method has been used in numerous of research fields. NIL technology is not yet utilized for displays industry, and we propose an alignment layer of the sol-gel process using NIL. One-dimensionally nanopatterned by polydimethylsiloxane sheets cause surface changes in hybrid SnGaO thin films mixed in a 3:7 ratio, which aligns the liquid crystals (LCs) uniformly in the line pattern direction. These surface changes are confirmed through atomic force microscopy data analysis, and changes in surface shapes for different the curing temperatures in the furnace are analyzed. X-ray photoelectron spectroscopy shows that the chemical composition of the thin films changes according to curing temperatures, and the intensities of SnO and GaO increase exponentially at 200 °C compared to those at 50 °C. Through this, the van der Waals force increases between surface molecules, in the anisotropic direction to help align the LCs. Furthermore, we performed polarized optical microscopy and pre-tilt angle analysis confirm that the LCs are energized uniformly. Finally, the performance of an actual display device transmittance and electro-optical properties; the transmittance of SnGaO is 4.51p% higher than that of the currently commercialized PI-rubbing, and the voltage-transmittance curve is a perfect graph.

A data-fitting method based on the whale optimization algorithm (WOA) is proposed to determine the thickness and refractive index of films measured by spectroscopic ellipsometry (SE). To demonstrate this method, tin oxide (SnO2) films with transparent wavelength coverage (400–800 nm) are evaluated. The comparative analysis indicates that Psi and Delta parameter curves based on WOA fitting align more closely with those obtained through experiments. Furthermore, the thickness and refractive index of films obtained by WOA are in nearly agreement with the results from the well-known Levenberg–Marquardt (LM) algorithm. This validation confirms that it has great potential in the determination of film parameters in ellipsometry data fitting.

This study explores the surface chemistry and electrical responses of ultra-high-sensitivity SnO2 MEMS arrays to enable a novel sequential detection methodology for detecting nitrogen dioxide (NO2) and ethanol (C2H5OH) as a route to achieve selective gas sensing in electronic nose (E-nose) applications. Utilizing tin oxide (SnO2) thin films deposited via atomic layer deposition (ALD), the array achieves the lowest reported detection limits of 8 parts per billion (ppb) for NO2. The research delves into the detection mechanisms of NO2 and C2H5OH, both individually and in subsequent exposures, assessing the sensor’s dynamic response across various operating temperatures. It demonstrates rapid response and recovery times, with averages of 48 s and 277 s for NO2 and 40 and 48 for C2H5OH. Understanding the role of individual gases on the SnO2 surface chemistry is paramount in discerning subsequent gas exposure behavior. The oxidizing behavior of C2H5OH following NO2 exposure is attributed to interactions between NO2 and oxygen vacancies on the SnO2 surface, which leads to the formation of nitrate or nitrite species. These species subsequently influence interactions with C2H5OH, inducing oxidizing properties, and need to be carefully considered. Principal component analysis (PCA) was used to further improve the sensor’s capability to precisely identify and quantify gas mixtures, improving its applicability for real-time monitoring in complex scenarios.

In this work, a study was made of the possibility of obtaining ceramics for microwave technology in the system of ZrO2–SnO2–TiO2 oxides by solid-phase synthesis using a sintering additive, lanthanum (III) oxide. Ceramics based on zirconium-tin titanate composition Zr0.8 Sn0.2 TiO4 with additions of 2, 4, and 6 wt.% La2O3, its properties were studied using various methods of analysis. The densest ceramic specimens were obtained at a firing temperature of 1400°C and a La2O3 content of 4 wt.%. [ABSTRACT FROM AUTHOR]

Biomass-derived carbon has received widespread attention as an environment-friendly lithium-ion anode material. Simultaneously, SnO2-based electrodes have inherent limitations and urgently need to be optimized. This article proposes a facile hydrothermal carbonization method to encapsulate SnO2 particles into biomass-derived carbon. As the anode electrode of a lithium-ion battery, the composite exhibits high reversible capacities of 1439 mAh g−1 and 1160 mAh g−1 after 150 cycles at 0.2 C and 1 C, respectively. In addition, it also has excellent rate performance (567 mAh g−1 at 5 C). The improvement in electrochemical performance can be attributed to the fact that SnO2 nanoparticles are embedded in the conductive carbon layer, shortening the diffusion length of Li+ and maintaining structural integrity. This presents an effective way to design high-performance electrode materials. [ABSTRACT FROM AUTHOR]

The sol-gel process was utilized to fabricate SnO2 nanoparticles, both in their pure form and with the addition of Ni dopants. The nanoparticles obtained were further examined to ascertain the characteristics associated with their structure, alterations in band gap, and photocatalytic performance. The insertion of nickel ions into tin sites hinders the formation of grain growth in tin oxide. The variation in the valence states and ionic radius of Sn4+ and Ni2+ ions, as revealed by X-ray diffraction (XRD) study, accounts for this disparity. FTIR measurements indicate the existence of stretching vibrations of metal-oxygen bonds that include Ni ions in the doped samples. The photoluminescence (PL) analysis reveals that the introduction of nickel doping alters the band structure of SnO2, leading to the creation of additional defect states, such as oxygen vacancies inside the crystal lattice. A study was undertaken to investigate the photocatalytic (PC) activity of SnO2 in the presence of Ni dopants. The results revealed a noticeable improvement in the efficiency of photodegradation. The degradation of Congo red (CR) dye using Ni–SnO2 nanocrystals achieves an efficiency of 94.88 % within a duration of 180 ​min. An analysis has been conducted on the impact of dye content, photocatalyst dosage, and pH on the degradation efficiency. As per the study, lower dose of Ni–SnO2 has shown better degradation efficiency in comparison to other studies. The improved performance of Ni–SnO2 can be ascribed to two main factors: the inhibition of carrier recombination due to the inclusion of defective states, and the production of hydroxyl radicals (OH•). The stability and reusability of these photocatalysts have been noted in their efficient application for environmental remediation.

Abstract Efficient inverted perovskite light‐emitting diodes (PeLEDs) are demonstrated by the introduction of tetraethyl orthosilicate (TEOS)‐incorporated tin oxide (SnO2) interlayer between the SnO2 electron injection layer and the perovskite emission layer. The TEOS incorporation into the SnO2 solution spontaneously converts it to a SiO2–SnO2 composite colloidal solution with a wide band gap, thermal stability, transparency, and chemical stability toward perovskite. The TEOS‐incorporated SnO2 interlayer effectively restricts the charge transfer from perovskite into SnO2 and promotes electron injection from SnO2 into perovskite due to the shift toward favorable energy band alignment. In addition, the TEOS‐treated interlayer balances the electron injection rate and the hole injection rate, thereby facilitating radiative recombination of the charge carriers injected into perovskite. As a result, the inverted PeLEDs exhibit significantly improved performance of 33 996 cd m−2 luminance, 9.99% of external quantum efficiency, and 44.83 cd A−1 of current efficiency.

In the present work, the feasibility of removing chemical oxygen demand (COD) from petroleum refiner wastewater (PRW) was examined through an anodic oxidation process using a SnO2-copper substrate anode in a prototype tubular batch electrochemical reactor. The SnO2 anode was prepared by cathodic deposition from a nitrate solution and characterized by techniques such as X-ray diffraction (XRD) and scanning electron microscopy (SEM). Effects of current density, [Sn2+]/[HNO3] molar ratio, and time on the properties of the prepared anode were investigated. The XRD results showed that main peaks corresponded to deposition of tetragonal SnO2. Besides, broad peeks were observed indicating that the deposits have a lower degree of crystallinity. The results confirmed that increasing current density higher than 10 mA/cm2 results in formation of a mixture of SnO2 and Sn deposits. Additionally, the results proved that [Sn2+]/[HNO3] molar ratio has the main effect on the electrodeposition process, where keeping this ratio lower than 0.33 is recommended to ensure pure SnO2 film deposition. The best conditions for electrodeposition of SnO2 as a compact film on a copper substrate were a current density of 10 mA/cm2, [Sn2+] of 25 mM, [HNO3] of 125 mM to make a molar ratio of 0.2, and 30 min to confirm the formation of deposits without cracks and having an atomic percent (Sn/O) of 20.6/65. The application of the prepared anode for removing of COD from PRW confirmed a good performance with a removal efficiency of 79 % at current density of 12 mA/cm2, pH of 7.8, and operating time of 150 min in which an energy consumption of 9.93 kWh/kg COD was required. The degradation of COD using the SnO2 electrode was found to obey a pseudo first-order kinetic. The application of anodic oxidation using the new configuration of the SnO2 anode can be considered an eco-friendly process for treating wastewater, featuring easy scale-up to an industrial scale at high removal efficiency and lower cost.

Lossy mode resonance (LMR) has garnered significant attention in sensor applications. LMR was primarily explored in fiber-based systems, however, there has been a recent upsurge in its application within planar waveguides. This article compares the LMR phenomenon in planar waveguides with the most employed coatings in the field, specifically SnO2, TiO2, and ITO. Additionally, the experimental findings are compared with simulations conducted using the finite element method (FEM) within the COMSOL Multiphysics environment. The novelty of this research lies in the integration of both experimental results and theoretical calculations, utilizing strong FEM simulation tools, in a single study.

Drilling mud is a major concerning element due to its high operational and economic impact on the drilling process. Various additives are introduced to enhance the efficiency of drilling fluid, but none of them could perfectly achieve their proposed efficacy in drilling operations. Researchers conceived several nanoparticles (NPs) in drilling fluid to dissolve this issue. In a singular instance, commercial tin oxide (SnO2) nanoparticles were utilized to analyze the influence of NPs on the rheological and filtration properties of inorganic KCl salt-based drilling fluid. However, the effect of SnO2 NPs on mud lubricity characteristics is not studied previously. However, due to the hazardous behavior of KCl, its use is very limited. Thus, we consider a KCl-free bentonite water-based mud to avoid any environmental damages from drilling operations. We also use SnO2 NPs that is synthesized in our laboratory by co-precipitation method. In addition to rheological and filtration properties, we also investigate the effect of NPs on mud's lubricity that was not considered in the previous study. Drilling fluid properties are measured at five different NPs concentrations of 0.10, 0.25, 0.50, 0.75 & 1.0 wt%, and at six different temperatures of 30, 40, 50, 60, 70, and 80 °C, while filtration properties are measured using API low-pressure low temperature (LPLT) condition. The addition of 0.1 wt% SnO2 NPs increases plastic viscosity, yield point, 10 s gel strength, and 10 min gel strength by 10%, 63%, 20%, and 14%, respectively. The maximum reduction in lubricity coefficient is found to be 14% at NPs concentration of 1.0 wt%. The NPs concentration of 0.5 wt% yielded a reduction in fluid loss and mud cake thickness by 8.1% and 34%, respectively. The study suggests that SnO2 NPs can be employed as an additive to improve the rheology, lubricity, and filtration properties of KCl-free bentonite water-based drilling mud.

Monitoring of air pollutions is one of actual trends in the development of industrial and domestic instrumentation. There are sets of tasks for improving gas analytical instruments because of increasing demand for control of a concentration of explosive and toxic gases on a level with maximum allowable concentration. The aim of the paper was to investigate the methods of formation and elemental composition of indium oxide films modified with tin oxide on the surface of gas sensor elements as one of the promising compounds for improving the detection efficiency of explosive and toxic gases in the environment. The processes of formation of gas-sensitive films deposited on the surface of nichrome alloy information electrodes were studied in this article. Substrates of anodic aluminum oxide with area of 10 × 10 mm2 and a thickness of 45 ± 0,5 μm were chosen for research. Two layers on the surface of the samples were formed. The first layer was formed from NiCr alloy (Ni – 80 %, Cr – 20 %) with a thickness of ≈ 0.3 μm by ion-plasma sputtering. The second layer was based on indium oxide with addition of tin oxide with thicknesses from ≈ 0.3 μm to ≈ 1.0 µm and coated with sol-gel technology. Five samples of gas-sensitive films were formed with different methods of deposition and heat treatment. Scanning electron microscopy was used for study of films’ morphology and elemental compositions of samples. The most perfect continuous semiconductor films were obtained by multilayer applying of a sol-gel paste. When semiconductor films were processed at annealing temperatures of 700 °C and higher in vacuum so there was observed cracking of semiconductor films up to a layer of NiCr alloy. The developed surface of gas-sensitive films allows to reach high sensitivity and affectivity of semiconductor sensors for control of air gas composition.

Polycrystalline SnO2-HfO2 nanolaminated thin films were grown by atomic layer deposition (ALD) on SiO2/Si(100) and TiN substrates at 300 °C. The samples, when evaluated electrically, exhibited bipolar resistive switching. The sample object with a stacked oxide layer structure of SnO2 | HfO2 | SnO2 | HfO2 additionally exhibited bidirectional threshold resistive switching properties. The sample with an oxide layer structure of HfO2 | SnO2 | HfO2 displayed bipolar resistive switching with a ratio of high and low resistance states of three orders of magnitude. Endurance tests revealed distinguishable differences between low and high resistance states after 2500 switching cycles.

Polycrystalline SnO2 thin films were grown by atomic layer deposition (ALD) on SiO2/Si(100) substrates from SnI4 and O3. Suitable evaporation temperatures for the SnI4 precursor as well as the relationship between growth per cycle and substrate temperature were determined. Crystal growth in the films in the temperature range of 225–600 °C was identified. Spectroscopic analyses revealed low amounts of residual iodine and implied the formation of single-phase oxide in the films grown at temperatures above 300 °C. Appropriateness of the mentioned precursor system to the preparation of SnO2 films was established.

Biomass has been considered an alternative source of electrode materials. Converting biomass into activated carbon is one of the possible approaches. Coffee ground waste is abundant as the world’s coffee-drinking culture grows. This paper describes a study that converted coffee grounds into activated carbon and tested its feasibility for electrode materials. We use a simple pyrolysis technique (800°C) to synthesize activated carbon from waste coffee grounds, with potassium hydroxide (KOH) as an activator. Tin oxide (SnO2), which has a high theoretical capacity, was impregnated into the carbon framework using a hydrothermal method operating at 180°C for 2 hours. The X-ray diffraction (XRD) pattern and Fourier transform infrared spectroscopy (FTIR) results show that SnO2 was successfully impregnated into the carbon structure. Raman analysis also shows that the carbon structure of the activated carbon still retains despite the presence of the metal oxide during the hydrothermal synthesis. Furthermore, electrochemical measurements utilizing the galvanostatic method using a three-electrode system demonstrated that the specific capacitance of the material increased by approximately 106% at 5 A/g following SnO2 impregnation. Long cycle testing further demonstrates that including SnO2 in the carbon, structure may sustain outstanding performance even at high current densities of 5 A/g for 100 cycles with 99% capacity retention. The results demonstrate the possibility of activated carbon from coffee ground waste composited with tin oxide as supercapacitor electrodes.

Complicated protocols have been used to tune the size of tin oxide nanoparticles (SnO2 NPs) in conventional chemical synthesis approaches. In this study, we addressed this issue through the combination of polarity solvent reduction and sonication as a potential strategy for optimizing the size of SnO2 NPs for anticancer applications. Then the anticancer activity and safety of synthesized SnO2 NPs on U-2OS human osteosarcoma cells and normal human osteoblast, NHOst, respectively, were assessed by several assays. SEM and TEM analyses revealed that synthesized SnO2 NPs had a spherical-shaped morphology with an average particle size of about 10 nm. FTIR result showed a broad absorption peak at 649 cm– 1, corresponding to the stretching vibration of the O–Sn–O bond. XRD analysis exhibited eight main peaks, revealing a tetragonal system of rutile-like structure. DLS study showed that synthesized SnO2 NPs had an average hydrodynamic size of 43.93 nm with a zeta potential value of −31.00 mV. Cellular assays displayed that SnO2 NPs mitigate the growth of U-2OS human osteosarcoma cells (IC50: 15.50 µg/mL) with partial cytotoxicity on normal osteoblasts. It was then discovered that SnO2 NPs triggered stress effects by raising the levels of LDH release, ROS, and MDA and lowering those of SOD, CAT activity, and GSH content. Also, it was discovered that SnO2 NPs activated both intrinsic and extrinsic signaling pathways mediated by MMP collapse, elevation of caspase-3, −9, −8 activities and corresponding mRNA, and upregulation of Bax/Bcl-2 mRNA ratio. Overall, this study found that extrinsic and mitochondrial apoptotic pathways can both be activated by synthesized SnO2 NPs to induce apoptosis in human osteosarcoma cells. This finding calls for additional research in the future.

To produce highly efficient and repeatable perovskite solar cells (PSCs), comprehending interfacial loss and developing approaches to ameliorate interfacial features is essential. Nonradiative recombination at the SnO2–perovskite interface in SnO2-based perovskite solar cells (PSCs) leads to significant potential loss and variability in device performance. To improve the quality of the SnO2 electron transport layer, a novel polymer-doped SnO2 matrix, specifically using polyacrylic acid, was developed. This matrix is formed by spin-coating a SnO2 colloidal solution that includes polymers. The polymer aids in dispersing nanoparticles within the substrate and is evenly distributed in the SnO2 solution. As a result of the polymer addition, the density and wetting properties of the SnO2 layer substantially improved. Subsequently, perovskite-based photovoltaic devices comprising SnO2 and Spiro-OMeTAD layers and using (FAPbI3)0.97(MAPbBr3)0.03 perovskite are constructed. These optimized devices exhibited an increased efficiency of 17.2% when compared to the 15.7% power conversion efficiency of the control device. The incorporation of polymers in the electron transport layer potentially enables even better performance in planar perovskite solar cells. [ABSTRACT FROM AUTHOR]

SnO2 nanorods were synthesized via a simple, facile, and cost-effective co-precipitation route using sodium dodecyl sulfate (SDS) as a surfactant. The structural, morphological, and electrochemical properties of the prepared SnO2 nanorods were investigated. Morphological analysis revealed the formation of rods due to the presence of anionic surfactant. Electrochemical analysis of the electrodes in an alkaline electrolyte revealed the pseudocapacitive behavior of the nanorods of SnO2. The tin oxide nanorods were capable of delivering maximum specific capacitance of 108 F g−1 at a specific current of 2 A g−1. Moreover, an asymmetric supercapacitor was fabricated utilizing SnO2 and activated carbon (AC) as electrodes. The fabricated two-electrode cell has remarkable power density of 1234 W kg−1. From these measurements, it can be concluded that SnO2 appears to be a promising pseudocapacitor material. [ABSTRACT FROM AUTHOR]

In this work, ZnO, SnO2, and their mixed ZnO-SnO2(25%) nanoparticles (NPs) were successfully green synthesized in a straightforward manner with a low-cost and environmentally friendly approach using a banana peel extract. The synthesized nanophotocatalysts were characterized using various techniques including FTIR, XRD, UV-Vis, TEM, SEM, BET, PL, EDS, and TGA. The characterization results showed that the ZnO and SnO2 powders were crystallized in a hexagonal wurtzite and rutile-type tetragonal structures, respectively, and their mixed ZnO-SnO2(25%) NPs contain both structures. Also, it was found that the addition of SnO2 into the ZnO structure reduces the PL intensity of the latter, confirming better separation of electron/hole pairs. The average particle size of a ZnO-SnO2(25%) NP photocatalyst was found to be 7.23 nm. The cationic dyes methylene blue (MB) and crystal violet (CV) as well as the anionic dyes naphthol blue black (NBB) and Coomassie brilliant blue R 250 (CBB) were employed as model dyes to assess the dye removal efficiencies of the biosynthesized nanophotocatalysts under sunlight. In all cases, the mixed ZnO-SnO2(25%) NP photocatalyst showed much better photocatalytic activity than individual photocatalysts. The degradation percent of dyes using ZnO-SnO2(25%) NPs ranged between 92.2% and 98%. The efficient photocatalytic activity of ZnO-SnO2(25%) NPs is attributed to the effective charge separation and reduced electron/hole recombination rate. The kinetic study results conformed to a pseudo first-order reaction rationalized in terms of the Langmuir–Hinshelwood model. Furthermore, the results showed that the ZnO-SnO2(25%) NP photocatalyst is highly stable and could be recycled several times without a noticeable reduction in its catalytic activity towards dye removal. [ABSTRACT FROM AUTHOR]

The aim of this work was to biosynthesize SnO2-decorated ZnO (ZT) nanocomposites (NCs) of different Sn content (10, 20, and 30 mol%), namely, ZT10, ZT20, and ZT30, using Olea europaea leaf aqueous extract-based phytocompounds as nanoparticle facilitating agents for application as effective photocatalyst in the removal of dyes from polluted water. The obtained ZT NCs were characterized using various techniques, including FTIR, XRD, TGA, TEM, EDS, UV–Vis, PL, and BET surface area. X-ray diffraction patterns show that rutile SnO2 and hexagonal ZnO coexist in the composites, and their crystallite size (D) is affected by the SnO2 ratio; the obtained D-values were 17.24, 19.07, 13.99, 6.45, and 12.30 nm for ZnO, SnO2, ZT10, ZT20, and ZT30, respectively. The direct band gaps of the ZT heterostructure increase with increasing SnO2 ratio (band gap = 3.10, 3.45, 3.14, 3.17, and 3.21 eV, respectively). TEM spectroscopy revealed nanorod and spherical grain morphologies of the composites, while EDS confirmed the elemental composition, the element ratio, and the composite's purity. All catalysts exhibit type III isotherm with macropore structure. The photocatalytic efficiency against cationic (methylene blue (MB), rhodamine B (RB)), and anionic (methyl orange (MO)) dyes, under sunlight, was optimal with ZT20. The results revealed almost complete degradation at 55, 65, and 55 min, respectively. Hence, it is evident that incorporating SnO2 improves the photocatalyst's performance, with an apparent optimal enhancement at 20 mol% Sn decorating ZT NCs. More interestingly, the catalyst stability and activity remained unaffected even after four activating cycles. [ABSTRACT FROM AUTHOR]

Tin(IV) oxide (SnO2) is a metal oxide renowned for its excellent optoelectronic properties. With the use of simple post-processing methods, the characteristics of SnO2 may be easily modified. In the current work, SnO2 thin films were prepared using the spray pyrolysis technique and were subjected to post-UV-ozone (UVO) treatment for different durations. Characterization techniques including x-ray diffraction, Raman spectroscopy, scanning electron microscopy, energy-dispersive spectroscopy, UV–visible spectroscopy, and photoluminescence spectroscopy were employed to assess the effects of UVO treatment. It was found that UVO treatment had no significant impact on the film's structural characteristics. However, after exposure to UVO, the bandgap was seen to decrease from 3.04 eV to 2.84 eV. Also, photoluminescence investigations revealed that UVO treatment increased the defects in the films with a decrease in the ratio between band-to-band emission and defect emissions. The results indicate that UVO treatment is an effective strategy for tuning the optical properties of SnO2 thin films by precisely managing the bandgap. [ABSTRACT FROM AUTHOR]

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The effects of Au addition on the acetone response of Cu2O-added porous SnO2 (pr-Cu2O-SnO2) powders, which were synthesized by ultrasonic spray pyrolysis employing polymethyl methacrylate microspheres as a template, were investigated in this study. The 3.0 wt% Au-added pr-Cu2O-SnO2 sensor showed the largest acetone response among all sensors. In addition, the magnitude of the acetone response was much larger than those of the ethanol and toluene responses. The catalytic activities of these gases over Au-added pr-Cu2O-SnO2 powders were also examined to clarify the key factors affecting their acetone-sensing properties. The Au addition increased the complete oxidation activity of all gases, and the complete oxidation activity of acetone was much higher than those of ethanol and toluene. These results indicate that the oxidation behavior during the gas-diffusion process in the sensitive Au-added pr-Cu2O-SnO2 layer of the sensors is quite important in enhancing the acetone-sensing properties.