Synthesis Of SnO2 Nanoparticles Research Articles

Phytosynthesis and characterization of tin-oxide nanoparticles (SnO2-NPs) from Croton macrostachyus leaf extract and its application under visible light photocatalytic activities

Nanotechnology is rapidly becoming more and more important in today's technological world as the need for industry increases with human well-being. In this study, we synthesized SnO2 nanoparticles (NPs) using an environmentally friendly method or green method from Croton macrostachyus leaf extract, leading to the transformation of UV absorbance to visible absorbance by reducing the band gap energy. The products underwent UV, FTIR, XRD, SEM, EDX, XPS, BET, and DLS for characterization. Characterization via UV–Vis spectroscopy confirmed the shift in absorbance towards the visible spectrum, indicating the potential for enhanced photocatalytic activity under visible light irradiation. The energy band gap for as-synthesized nanoparticles was 3.03 eV, 2.71 eV, 2.61 eV, and 2.41 eV for the 1:1, 1:2, 1:3, and 1:4 sample ratios, respectively. The average crystal size of 32.18 nm and very fine flakes with tiny agglomerate structures of nanoparticles was obtained. The photocatalytic activity of the green-synthesized SnO2 nanoparticles was explored under visible light irradiation for the degradation of rhodamine B (RhB) and methylene blue (MB), which were widespread fabric pollutants. It was finally confirmed that the prepared NPs were actively used for photocatalytic degradation. Our results suggest the promising application of these green-synthesized SnO2 NPs as efficient photocatalysts for environmental remediation with low energy consumption compared to other light-driven processes. The radical scavenging experiment proved that hydroxyl radicals (_OH) are the predominant species in the reaction kinetics of both pollutant dyes under visible light degradation.

Photocatalytic degradation of Sudan black B dye by using synthesized SnO2 nanoparticles as a catalyst: factorial design, kinetic and isotherm models

Photocatalytic degradation of Sudan black B dye by using synthesized SnO2 nanoparticles as a catalyst: factorial design, kinetic and isotherm models

Distinctive Effects between Hydrothermal and Ultrasound Synthesized SnO2 Nanoparticles on Ceramic Bi1.6Pb0.4Sr2Ca2Cu3O10+δ Superconductor

The effect of additions of two series of SnO2 nanoparticles synthesized using two different methods on crystal structure and superconductivity of Bi1.6Pb0.4Sr2Ca2Cu3O10+δ (BPSCCO) superconductors was investigated. Two series of spherical SnO2 nanoparticles were synthesized independently by using ultra-sonication (US-SnO2) and hydrothermal (HT-SnO2) methods. Polycrystalline samples of (Bi1.6Pb0.4Sr2Ca2Cu3O10+δ)1−x(SnO2)x, where x ranged between 0, 0.002 and 0.004, were fabricated by the solid-state reaction method. X-ray diffraction patterns showed a decrease in the volume fraction of the Bi-2223 and an increase in that of the Bi-2212 phases. Scanning electron microscopy images presented the “needle-like blossom” on the surface of the US-SnO2 doped samples, while the phenomenon was not found on the HT-SnO2 doped samples. The Tc was decreased extremely with US-SnO2 doping while slightly HT-SnO2 nanoparticle-doped samples. The field dependence of Jc, Jc(B), showed the opposite tendencies on two series of samples: Jc(B) was enhanced on the HT-SnO2 nanoparticle-doped samples, and that was decreased on UT-SnO2 nanoparticle-doped samples. The application of the Dew-Hughes model to explore the flux pinning mechanism exhibited that the point-like pinning centers were dominant on the HT-SnO2 doped samples. On US-SnO2 doped samples, however, the additional pinning center type was not found and could be explained by the observed over-sized SnO2 nano-needle.
 
 

A new method in the production of protective sheets against X-ray radiation

Today, the use of X-rays in diagnosing and sometimes treating patients is inevitable. Despite the many benefits of using X-rays in medical and other sciences, the harmful effects of this radiation on human tissue should not be neglected. One of the best ways to prevent the harmful effects of X-rays on the human body is to use appropriate covers against these rays. It seems that it is necessary to find effective particles to weaken X-rays and choose a suitable substrate with high mechanical resistance to scatter particles in it. In this study, the synthesis of SnO2 nanoparticles from SnCl2.2H2O precursor and BaSO4 nanoparticles from BaCl2.2H2O precursor using neem tree extract (Azadirachta indica) as a reducing and stabilizing agent is reported. After the synthesis of nanoparticles, their structure was investigated by X-ray diffraction, scanning electron microscopy and energy dispersive X-ray analysis. Then the desired composite and nanocomposite were prepared in the polymer substrate. The sheets were prepared using an extruder and then a hot hydraulic press. The output sheets had a thickness of 1 mm. The structural characteristics of the produced sheets such as surface morphology, density of prepared composites, mechanical properties, thermal gravimetric analysis and retention of loaded particles after three times washes were investigated. The X-ray attenuation capability of each sample was evaluated by calculating the linear attenuation coefficient for each prepared sample. The results show that all sheets filled with tin and barium micro and nano particles have more X-ray attenuation capabilities than pure polymer. Among the prepared sheets, the nanocomposite prepared from low-density polyethylene (77 %) + SnO2 (10 %) + BaSO4 (10 %) + multi-walled carbon nanotubes (3 %) showed the highest X-ray attenuation.

Structural, optical, and dielectric properties of hydrothermally synthesized SnO2 nanoparticles, Cu/SnO2, and Fe/SnO2 nanocomposites

The structural and optical properties, as well as dielectric characteristics at various frequencies (0.1 Hz—20 MHz) and temperatures, T (300–400 K), of hydrothermally synthesized SnO2 nanoparticles, Cu/SnO2, and Fe/SnO2 composites have been investigated. The crystal structure is mostly formed of a tetragonal SnO2 phase, with a second phase of monoclinic CuO or rhombohedral Fe2O3 detected in Cu/SnO2, and Fe/SnO2 composites, respectively. The direct optical band gap, residual dielectric constant, and density of charge carriers are increased, while ac conductivity (σ ac) and dielectric constant decreased in Cu/SnO2 and Fe/SnO2. The value of σ ac was decreased while the electric Q-factor was increased by increasing T. SnO2 obeyed the hole-conduction mechanism for 400 ≥ T (K) ≥ 300, while Cu/SnO2 and Fe/SnO2 obeyed the electronic-conduction mechanism for 400 ≥ T (K) > 300. The binding energy is independent of T for SnO2, whereas it increases with rising T for Cu/SnO2 and Fe/SnO2 composites. F-factor and electronic polarizability are improved by a rise of T for SnO2 and Cu/SnO2 meanwhile are decreased for Fe/SnO2. The electrical impedance of the grains and their boundaries as well as equivalent capacitance are increased by increasing T and have higher values for Fe/SnO2 at T > 300 K. The obtained results recommend the synthesized Cu/SnO2 and Fe/SnO2 composites to be used as catalysts for water purification, anodes for lithium batteries, supercapacitors, and solar cell applications amongst others.

Chemical assist rapid sonochemical synthesis of Cr doped SnO2 nanoparticles for the hydrogen gas sensing application

An effective chemical assist Sonochemical method was used to synthesize facile and homogenous undoped and Cr (3, and 6 at. %) doped SnO2 nanoparticles within aqueous solution. Different characterization methods, including X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray (EDX), UV–vis spectroscopy Fourier Transform Infrared Spectroscopy (FTIR), Raman Spectroscopy and gas sensing were used to examine the structural, optical and chemical behavior of the synthesized SnO2 nanoparticles. The XRD results showed that the synthesized SnO2 nanoparticles exhibit high crystallinity and rutile phase. The synthesized SnO2 nanoparticles had an average crystallite size of 7.8 ± 2 nm. Crystallite size is found to be decreased when chromium is doped in SnO2 at different concentrations.The morphology of SnO2 nanoparticles was studied by FESEM, and the results showed that the developed SnO2 nanoparticles are uniform, spherical, and evenly dispersed. The SnO2 nanoparticles were investigated by EDS's chemical technique. The chromium, oxygen peak and Sn peak are present, according to the EDS spectra. The doping concentrations of Cr (3 % and 6% wt.) confirmed from the EDS spectrum. The Optical band gap of Undoped and Cr doped SnO2 nanoparticles were evaluated by UV–Vis Spectroscopy. The results demonstrated that band gap of the SnO2 nanoparticles increased with addition of the Cr contents. Fourier Transform Infrared Spectroscopy was used to analyze the chemical characteristics of SnO2 nanoparticles. The Sn-O band stretching was confirmed from the FT-IR investigation. Further, the rutile tetragonal phase confirmed the A1g vibration mode of the Rutile SnO2 symmetry from Raman spectroscopy. Finally, the gas sensing characteristics of the SnO2 nanoparticles were studied at 270 °C the resistances versus ambient gas time. It has been observed that sensitivity of the prepared sample was higher than reported in the literature.

Rheology and lubricity characteristics study at different temperatures using synthesized SnO2 nanoparticles in KCl free bentonite water base mud

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.

Pluronic-F-127-Passivated SnO2 Nanoparticles Derived by Using Polygonum cuspidatum Root Extract: Synthesis, Characterization, and Anticancer Properties.

Nanotechnology has emerged as the most popular research topic with revolutionary applications across all scientific disciplines. Tin oxide (SnO2) has been gaining considerable attention lately owing to its intriguing features, which can be enhanced by its synthesis in the nanoscale range. The establishment of a cost-efficient and ecologically friendly procedure for its production is the result of growing concerns about human well-being. The novelty and significance of this study lie in the fact that the synthesized SnO2 nanoparticles have been tailored to have specific properties, such as size and morphology. These properties are crucial for their applications. Moreover, this study provides insights into the synthesis process of SnO2 nanoparticles, which can be useful for developing efficient and cost-effective methods for large-scale production. In the current study, green Pluronic-coated SnO2 nanoparticles (NPs) utilizing the root extracts of Polygonum cuspidatum have been formulated and characterized by several methods such as UV-visible, Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray (EDAX), transmission electron microscope (TEM), field emission-scanning electron microscope (FE-SEM), X-ray diffraction (XRD), photoluminescence (PL), and dynamic light scattering (DLS) studies. The crystallite size of SnO2 NPs was estimated to be 45 nm, and a tetragonal rutile-type crystalline structure was observed. FESEM analysis validated the NPs' spherical structure. The cytotoxic potential of the NPs against HepG2 cells was assessed using the in vitro MTT assay. The apoptotic efficiency of the NPs was evaluated using a dual-staining approach. The NPs revealed substantial cytotoxic effects against HepG2 cells but failed to exhibit cytotoxicity in different liver cell lines. Furthermore, dual staining and flow cytometry studies revealed higher apoptosis in NP-treated HepG2 cells. Nanoparticle treatment also inhibited the cell cycle at G0/G1 stage. It increased oxidative stress and promoted apoptosis by encouraging pro-apoptotic protein expression in HepG2 cells. NP treatment effectively blocked the PI3K/Akt/mTOR axis in HepG2 cells. Thus, green Pluronic-F-127-coated SnO2 NPs exhibits enormous efficiency to be utilized as an talented anticancer agent.

COVID-19 chloroquine drug detection using novel, highly sensitive SnO2-based electrochemical sensor

A highly sensitive, selective, stable, and cost-effective SnO2-based electrochemical sensor is reported for the detection of chloroquine phosphate (CQP). Hydrothermal synthesis is used to synthesize SnO2 nanoparticles, which are mixed with graphite and form a highly electrochemically active composite. The SnO2 nanoparticles and SnO2/graphite composite are fully characterized physico- and electrochemically. Using the optimal SnO2/graphite composite, an excellent analytical performance is demonstrated with an electrode sensitivity of 35.7 µA/µM.cm2, a linear range of 0.1–23.3 µM, and limits of detection and quantification of 0.01 µM and 0.04 µM, respectively. High CQP selectivity with minimal interference at 100 × concentration of interferents is shown. The sensor is also highly repeatable and reproducible with RSD of 2.46 % and 1.86 %, respectively, and can retain > 85 % of its activity upon storage. The validity of the new sensor for real sample analysis is shown by applying it to CQP tablets using the standard addition method, obtaining an excellent percentage recovery of ∼ 102 %. The low cost, facile processing, and superior performance of the SnO2/graphite electrode make it an up-and-coming candidate for the commercial electrochemical detection of CQP and other small molecules.

Structural, morphological and anti - bacterial activities of pure SnO2 nanoparticles prepared by chemical precipitation method

The tin oxide (SnO2) nanopowders were synthesized by a simple chemical method (precipitation). The sample was studied for XRD, FESEM, and EDX analyses. The XRD results of synthesized SnO2 nanoparticles exhibited a tetragonal structure withan average crystallite size of 18.79 nm. The FE-SEM exhibited the microstructure of the prepared nanoparticles. The FESEM images reveal that the shape of the prepared product wasspherical. The impact of SnO2 NPs on food and water poisoning growth was investigated with the help of antibacterial activities. This paper deals with the properties and applications of tin oxide nanostructures. Antibacterial activity was carried out againstthree bacterial strains: Bacillus subtilis, Escherichia Coli, and Pseudomonas aeruginosa.

Photocatalytic and biological activities of green synthesized SnO2 nanoparticles using Chlorella vulgaris

To produce tin oxide (SnO2 ) nanoparticles (NP) with microalga for use in azo dye-polluted wastewater treatment and to optimize the conditions to synthesize as small NPs as possible. The green microalga Chlorella vulgaris mediated NPs were synthesized after an optimization process utilizing the statistical response surface methodology (RSM). The optimized synthesis conditions were 200 W microwave power, 0.5 mM SnCl2 concentration and 200°C calcination temperature. Methyl orange (MO) was studied for its photocatalytic degradation with UV. Antibacterial activity against four pathogenic bacteria was studied using the well diffusion method. Cytotoxicity was measured using the MMT assay with lung cancer cell line A549, and antioxidant activity using DPPH radical scavenging. Following the optimization of their production, the produced crystalline SnO2 NPs were on average 32.2nm (by XRD) with a hydrodynamic size of 52.5nm (by LDS). Photocatalytic degradation of MO under UV was nearly complete (94% removal) after 90 min and the particles could be reused for 5cycles retaining 80% activity. The particles had antibacterial activity towards all five tested bacterial pathogens with the minimum inhibitory concentrations ranging from 22 to 36 μg/ml. The minimum bactericidal NP concentration varied between 83 and 136 μg/ml. Antioxidant activity was concentration dependent. A cytotoxicity was determined towards A549 cells with an LD50 of 188 μg/ml after 24 h of incubation, a concentration that is much higher than the active concentration for dye removal ranging from 22 to 36 μg/ml. After optimization, SnO2 nanoparticles produced with C. vulgaris displayed high photocatalytic activity at concentrations below their antibacterial and cytotoxic activities. The SnO2 nanoparticles produced with the help of microalgae are suitable for the removal of MO dye from wastewater. Further applications of this green technology can be expected.

Sun light-assisted enhanced photocatalytic activity and cytotoxicity of green synthesized SnO2 nanoparticles

• SnO 2 has been successfully synthesized using C. indica plant leaves extract. • Photocatalytic activity towards Rhodamine B (RhB) dye under visible light illumination. • Photocatalytic activity of the synthesized samples against RhB indicated superior activity with degradation percentages of 97%. • Cytotoxic assessment of the synthesized samples using Artemia salina ( A. salina ) In this work, SnO 2 NPs were green synthesized using Canna indica ( C. indica ) plant leaves extract and the synthesized powder sample was calcined at different temperatures from 400 to 700 °C. The synthesized sample was characterized using XRD, UV–vis, and FTIR spectra. Furthermore, the photocatalytic activity using Rhodamine B (RhB) dye under visible light illumination of SnO 2 nanostructures calcined at different temperatures was tested. RhB was decomposed greater than 97% by all the samples under sunlight irradiation within 30 min while a maximum decomposition of 46% was achieved when exposed to UV lamp irradiation under similar experimental conditions and the reaction was satisfactorily described by pseudo-first-order reaction kinetics. Also, its cytotoxic assessment for Artemia salina ( A. salina ) was performed.The sample calcined at 600 °C exhibits greater toxicity for A. salina with a survival rate of 45 and 33% for 12 and 24 h exposure to visible light. So, the synthesized SnO 2 NPs are promising for the photodegradation of dyes and inhibiting the growth of A. salina animals in saline waters.

A Green Synthesized SnO<sub>2</sub> Photo-Catalyst for Effective Degradation of Biomedical Industrial Waste

Using a green synthesis approach, we have synthesized SnO2 nanoparticles. The morphology of the nanoparticles are characterise by scanning electron microscopy. The UV-vis spectroscopy technique was used to study the optical characteristics. The different parameters such as dosage of catalyst, initial concentration of drugs, effect of pH and other parameters were estimated. The Visible light was irradiated over sample solution at different pH values, and the photo-catalytic effect of the SnO2 nanoparticle was observed for degradation of ciprofloxacin drugs. The absorption spectra showed a stronger absorption peak at 273 nm representing the ciprofloxacin drugs. The photo-generated electron of nanoparticles degradation drugs, which shows decrease absorption intensity. The results revealed that the photo-catalytic degradation process works well at pH 7. The higher degradation efficiency was observed by following the pseudo-first-order kinetics.

Mechanochemically induced solid-state CO2 capture during the synthesis of SnO2 nanoparticles

Mechanochemistry offers a versatile method to synthesize metal oxides by the reaction of the corresponding metal salt and Na2CO3, with CO2 as a by-product. It is possible to monitor the progress of the reaction and even calculate conversion values based on the measured pressure increase in the milling equipment. We studied the kinetics of tin oxide formation in the mechanochemical reaction between SnCl2 and Na2CO3. Our systematic experiments revealed unexpected complexity in the temporal pressure function depending on the exact composition of the reactant mixture: the pressure exhibited a clear local maximum, and pressure values even dropped close to their starting value by the end of the reaction when Na2CO3 was present in 100% excess. This anomaly can be explained by realizing that CO2 is captured as NaHCO3 in a process analogous with aqueous flue gas treatment, and it can also be released in the secondary reaction between unreacted SnCl2 and NaHCO3. Here we provide experimental evidence to support this hypothesis and to draw attention to the pitfalls of oversimplifying pressure-based conversion calculations in mechanochemical processing.

Enhanced NO2‐Sensing Properties of Cu‐Loaded SnO2 Nanoparticles Synthesized via Precipitation and Impregnation Methods

Herein, NO2 noxious gas sensors based on precipitation/impregnation synthesized SnO2 nanoparticles loaded with Cu2O (Cu2O–SnO2) are presented. The particle properties are characterized by nitrogen adsorption, X‐ray spectroscopic, and microscopic analyses. The NO2‐sensing performances in terms of sensor response, response times, selectivity, and stability are optimized by varying Cu contents. The optimal sensing film (1.0 wt%Cu–SnO2) shows a high sensor response of ≈5680–5 ppm of NO2 at a low operating temperature of 200 °C. In addition, 1.0 wt%Cu–SnO2 sensor exhibits very high NO2 selectivity against SO2, H2S, C2H5OH, H2, C2H2, C2H4, and CH4 compared with unloaded one. Therefore, the 1.0 wt%Cu–SnO2 sensor is a promising candidate for highly sensitive and selective detection of NO2.

Flower-like SnO2 Nanoparticle Biofabrication Using Pometia pinnata Leaf Extract and Study on Its Photocatalytic and Antibacterial Activities.

The present study reported biofabrication of flower-like SnO2 nanoparticles using Pometia pinnata leaf extract. The study focused on the physicochemical characteristics of the prepared SnO2 nanoparticles and its activity as photocatalyst and antibacterial agent. The characterization was performed by XRD, SEM, TEM, UV-DRS and XPS analyses. Photocatalytic activity of the nanoparticles was examined on bromophenol blue photooxidation; meanwhile, the antibacterial activity was evaluated against Klebsiella pneumoniae, Escherichia coli Staphylococcus aureus and Streptococcus pyogenes. XRD and XPS analyses confirmed the single tetragonal SnO2 phase. The result from SEM analysis indicates the flower like morphology of SnO2 nanoparticles, and by TEM analysis, the nanoparticles were seen to be in uniform spherical shapes with a diameter ranging from 8 to 20 nm. SnO2 nanoparticles showed significant photocatalytic activity in photooxidation of bromophenol blue as the degradation efficiency reached 99.93%, and the photocatalyst exhibited the reusability as the degradation efficiency values were insignificantly changed until the fifth cycle. Antibacterial assay indicated that the synthesized SnO2 nanoparticles exhibit an inhibition of tested bacteria and showed a potential to be applied for further environmental and medical applications.

Development of a Sensor Array Based on Pt, Pd, Ag and Au Nanocluster Decorated SnO2 for Precision Agriculture

Introduction Nowadays, precision farming is a key topic. Because of the steady increase in the world's population, which is expected to reach 9.6 billion by 2050, it is vital to increase the productivity of agricultural land while reducing waste of water, fertilizers, pesticides and pesticide. To achieve these goals, precision agriculture aims to provide farmers with a wealth of information to optimize field management, by matching farming practices more closely to crop needs. This information is obtained exploiting satellite and weather data, and wireless sensor arrays, which combined with the use of GPS, Internet of Things (IoT) and machine learning allow the farmer to operate with both a control and predictive approach [1].For the best use of precision agriculture, it is therefore essential to collect as much data as possible on the crop status. On the one hand, various technologies have been developed or improved to collect information directly in the field, in particular to measure the pH, the nitrogen compound concentrations and the humidity amount in the soil [2,3]. On the other hand, there is not yet a well-structured system for monitoring crop gas emissions, which together with the control of soil parameters, can lead to a comprehensive evaluation of the effective health status and growth of the crop [4]. In this work, a sensor array composed of four different sensing materials, i.e. SnO2 decorated with Ag, Pd, Pt and Au nanoclusters, were developed and investigated to selective detect five different gases commonly present or emitted by crops. Material and Method SnO2 nanoparticles were synthesized by means of sol-gel technique, by dissolving Sn(II) ethylhexanoate in a hydroalcoholic solution of water and 2-propanol. Afterwards, it was adopted a simple impregnation method to add the metal nanoclusters. For instance, to obtain the decoration with Au nanoclusters, SnO2 nanoparticles were kept stirred in a water solution together with AuBr3, at room temperature. The nanopowder was then calcined at 650°C for 2 hours.The four sensing materials were then screen printed onto alumina substrates, which were equipped with a Pt heater and Au interdigitated electrodes.The gas sensors were then tested with five different gases commonly present or emitted by crops: ethylene, isoprene, CO, methanol and ammonia. They were analyzed five different concentrations of ethylene, methanol and CO and three concentrations of isoprene and ammonia, respectively. The sensing responses were collected by thermo-activating the sensing materials at four different temperatures: 200, 250, 300 and 350°C.The response values from the sensors, combined in a 3-dimensional point for each gas concentration, were processed through a Support Vector Machine (SVM) with a linear kernel to improve sensors selectivity. A first set was used to train the system, and a second one was used to optimize and test its performance. Results and Conclusions The Scanning Electron Microscope (SEM) analysis highlighted that the average size of the synthesized SnO2 nanoparticles was about 30-40 nm (Figure 1), while the X-ray Diffraction (XRD) highlighted a single crystalline phase (cassiterite). The SEM images showed that the metal nanoclusters were growth over the SnO2 nanoparticles surface, without modifying the SnO2 morphology, average size and crystalline structure (XRD) of SnO2. The weight concentration of metals in decorated samples was lower than 1% (Figure 2).The gas sensing characterization was performed in a sealed aluminum gas chamber, by exploiting certified cylinders of target gases and mass flow controllers. The Figure 3 shows the Principle Component Analysis (PCA) for the SnO2/Pt gas sensors vs. tested gases. As it can be observed, the PCA clearly discriminates the different concentrations of gases. The Figure 4 a) and b) show the results obtained in the test set of gas sensing responses with SnO2/Pt gas sensor, after the training of the SVM with linear kernels fit, carried out to build the classification model. The position of each point of the test set was compared with the trained model and thus classified. Figure 4a) highlights that there was a perfect SVM classification (100%) of the different concentration of the tested gases (21 points) for the SnO2/Pt, with a relative low error in the estimated concentrations compared to the real ones (Figure 4b). The same data analysis was then performed for the other sensing materials: Ag, Au and Pd/SnO2. Finally, the SVM classification was also carried out by combining all the gas sensing responses of the four different gas sensors, by achieving a perfect classification of the gases analyzed together with a very low error in the estimated concentrations, compared with the concentrations injected in the gas chamber.

Environmental benign synthesis of tin oxide (SnO2) nanoparticles using Actinidia deliciosa (Kiwi) peel extract with enhanced catalytic properties

The study deals with the biological exploration of tin oxide (SnO2) nanoparticles with the aid of Actinidia deliciosa (Kiwi) peel extract. The synthesized SnO2 nanoparticle exhibits a UV–visible absorption spectrum at around 290 nm. The phytoconstituents present in Actinidia deliciosa (Kiwi) peel extract act as a reducing and capping mediator was probed using Fourier transform infrared spectroscopy (FTIR). The morphological analysis of the synthesized nanoparticles was analyzed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed the nanoparticles were spherical with the size ranging from 5 to 10 nm. The chemical purity of the nanoparticles was analyzed using EDX analysis. Further, the catalytic efficiency of the synthesized SnO2 nanoparticles was examined for Methylene blue (MB), Methyl orange (MO), and Rhodamine B (RhB) dyes. The results exhibit the nanoparticles act as an efficient catalyst for the degradation of textile dyes in 8 min, 8 min, and 6 min with the degradation efficiency of 89%, 87%, and 97%. Hence the fabricated SnO2 nanoparticles with reduced size showed enhanced catalytic activity towards degradation of several textile dyes. Hence from the obtained results it was scrutinized that the synthesized SnO2 nanoparticles exhibit excellent catalytic activity in short time at room temperature and it remains constant for several cycles. So the synthesized SnO2 nanoparticles act a potent candidate for the degradation of anthropogenic pollutants.

Lanthanum doped tin oxide: Synthesis, characterization and application

This paper describes the synthesis of La-doped SnO2 nanoparticles for resistive-type relative humidity sensors. The structural characterization of synthesized SnO2 nanoparticles was analyzed using X-ray Diffraction (XRD), that exhibited the formation of the tetragonal rutile structure of pristine and La-doped SnO2 nanoparticles with a decrease in crystallite size in presence of different doping levels. Further increase in doping concentration (at 5 M%) revealed the formation of the La2O3 phase due to the excess amount of lanthanum. The UV–Vis spectroscopy indicates the doping of lanthanum (La) improves the optical property of pristine SnO2. The morphological characterization demonstrates the spherical-shaped nanoparticles. The synthesized nanoparticles were tested for relative humidity (RH) sensing application over the range of 10–100% RH at room temperature. The doping of 3 M% La-doped SnO2 shows good sensitivity (95%) than pristine SnO2 nanoparticles. The fabricated 3 M% La-doped SnO2 sensor not only showed better sensitivity and linear range over 10–100%RH, but also exhibited rapid response (8sec) and recovery (13sec) time than the pristine and the others La-doped levels of SnO2 nanoparticles. This better humidity sensing response of 3 M% La-doped nanoparticles was achieved due to high carrier density and small crystallite size. This indicates 3 M% La-doped nanoparticles is a promising material for room temperature humidity sensing.

Structural, optical and magnetic properties of SnO2 nanoparticles synthesized via surfactant-free hydrothermal process

Tin oxide (SnO2) nanoparticles are synthesized at different molar concentrations by employing a surfactant-free hydrothermal process. The structural properties of the samples investigated using XRD analysis indicated that the synthesized SnO2 nanoparticles have pure crystalline phase with tetragonal crystal structure of P42/mnm space group. The surface morphology analyzed using SEM micrographs showed that the nanoparticles get agglomerated without any specific structure. Optical characterization using UV–visible and PL spectroscopic techniques indicated that the synthesized SnO2 nanoparticles have absorption in the ultraviolet region and emission in the visible region due to defect states. A weak room-temperature ferromagnetism (RTFM) exhibited by the nanoparticles has been observed from the analysis of magnetic parameters.