Structure Of SnO2 Research Articles

Optoelectronic, photocurrent sensitivity and photocatalytic dye degradation behaviour of spray deposited Cr doped SnO2 thin films

Undoped and SnO2:Cr doped thin films (Cr: 0.25, 0.50, 0.75 and 1 wt%) were deposited by economically home-made spray pyrolysis method. The characteristic behaviour of the deposited films was studied by X-ray diffraction (XRD), Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Photoluminescence (PL), Ultraviolet–visible (UV–vis.) spectroscopy, Current-Voltage (I–V) and photocatalytic studies. The XRD analysis confirms the tetragonal rutile structure of SnO2 with predominant orientation along the (2 1 1) plane and the decrease in crystallite size from 48 to 30 nm by Cr-doping. The EDAX and XPS studies reveal the elements and its chemical state of Sn, O and Cr. The SnO2:Cr thin films exhibit an 85% average optical transmittance in the visible region of the electromagnetic spectrum. The SEM micrographs clearly show the well-defined grains with boundaries, and it is evident that grain size drastically reduces from 155 nm to 48 nm as a function of Cr-doping. Photoluminescence analysis confirms the defect-related emission (360 nm, 440 and 490 nm). The photocatalytic activity of all thin films is assessed using malachite green (MG) dye under UV light irradiation. 0.75 wt% Cr-doped SnO2 film shows improved photocatalytic performance (60.37%) than undoped thin film (32.03%). The I–V characteristics of undoped and SnO2:Cr thin films are performed in visible light, showing photo-linear response behaviour. The highest figure of merit (FOM) obtained for SnO2:Cr (0.75 wt%) thin film is 7.07 × 10−6 Ω−1. The obtained values of the FOM and photocatalytic performance are discussed in the context of the suitability of these materials for transparent and conducting window materials in solar cells and photocatalytic degradation applications.

Novel Bilayer SnO2 Electron Transport Layers with Atomic Layer Deposition for High-Performance α-FAPbI3 Perovskite Solar Cells.

Perovskite solar cells (PSCs) based on the SnO2 electron transport layer (ETL) have achieved remarkable photovoltaic efficiency. However, the commercial SnO2 ETLs show various shortcomings. The SnO2 precursor is prone to agglomeration, resulting in poor morphology with numerous interface defects. Additionally, the open circuit voltage (Voc ) would be constrained by the energy level mismatch between the SnO2 and the perovskite. And, few studies designed SnO2 -based ETLs to promote crystal growth of PbI2 , a crucial prerequisite for obtaining high-quality perovskite films via the two-step method. Herein, we proposed a novel bilayer SnO2 structure that combined the atomic layer deposition (ALD) and sol-gel solution to well address the aforementioned issues. Due to the unique conformal effect of ALD-SnO2 , it can effectively modulate the roughness of FTO substrate, enhance the quality of ETL, and induce the growth of PbI2 crystal phase to develop the crystallinity of perovskite layer. Furthermore, a created built-in field of the bilayer SnO2 can help to overcome the electron accumulation at the ETL/perovskite interface, leading to a higher Voc and fill factor. Consequently, the efficiency of PSCs with ionic liquid solvent increases from 22.09% to 23.86%, maintaining 85% initial efficiency in a 20% humidity N2 environment for 1300 h.

Evolution between Volatile and Nonvolatile Resistive Switching Behaviors in Ag/TiOx/CeOy/F-Doped SnO2 Nanostructure-Based Memristor Devices for Information Processing Applications

It is well known that higher requirements have been put forward for the computing efficiency and storage speed of the data processing of memory devices in the post Moore era. In particular, if a memory device with multiple physical characteristics can be developed, it will play an important role in realizing multifunctional applications of electronic systems. Here, a nanoscale memristor device with a Ag/TiOx/CeOy/F-doped SnO2 structure was prepared, which shows many interesting physical phenomena with the changing of the applied voltage. In the low-voltage region (<1.5 V), the device presents a volatile property, while it presents a nonvolatile behavior when a higher voltage (>2 V) was applied. Interestingly, the non-zero-crossing current–voltage (I–V) hysteresis behavior caused by the internal electromotive force appears in the voltage region of 0.5–1 V. Furthermore, as the applied voltage increases, the device gradually displays ideal memristor behavior and exhibits the standard resistance switching characteristic accompanied by the negative differential resistance effect in the region of 3.5–4.0 V. Therefore, this nanoscale device with multiple physical properties opens up a promising way for understanding the emerging physical phenomena, and it will be expected to become a potential candidate for the next generation of multifunctional electronic devices.

In situ growth of CsPbBr3 quantum dots in mesoporous SnO2 frameworks as an efficient CO2-reduction photocatalyst

Perovskite CsPbBr3 quantum dots (QDs) have shown great promise in photocatalytic applications but their performance is still largely restricted by severe charge recombination, weak stability, and poor CO2 capturing ability. Herein, CsPbBr3 QDs were grown in situ into mesoporous SnO2 frameworks and a unique CsPbBr3 @SnO2 heterostructure with enhanced CO2-reduction activity and stability was designed. The experimental results and theoretical calculations indicated that the electrons in the CsPbBr3 @SnO2 heterostructure transferred in an S-scheme mechanism, which greatly promoted the charge transfer between CsPbBr3 and SnO2. Besides, the unique porous structure of SnO2 facilitated the CO2 adsorption on the surface of the CsPbBr3 @SnO2 heterostructure. Benefitting from these synergistic effects, the developed CsPbBr3 @SnO2 heterostructure behaved remarkable activity toward CO2 reduction, which was about 3.12- fold higher than pristine CsPbBr3 QDs. This study provides a new pathway to design perovskite-based heterojunction photocatalysts for highly efficient CO2 conversion.

Conversion of p-type SnO to n-type SnO2 via oxidation and the band offset and rectification of an all-Tin oxide p-n junction structure

p-Type Tin monoxide (SnO) is a metastable phase and can be oxidized into n-type SnO2 in an O2 environment during growth and post-growth annealing. Here we first grow SnO thin films by RF magnetron sputtering with different oxygen partial pressure in the sputtering gas followed by rapid thermal annealing (RTA) in O2 to obtain n-type conducting SnO2 films. We found that while after RTA in N2 stoichiometric SnO film is p-type conducting, films sputtered with excess O and RTA in O2 crystallize in rutile SnO2 structure and exhibit n-type conductivity. Exploiting the transformation of p-SnO to n-SnO2 through oxidation, we fabricate an all-Tin Oxide transparent p-n quasi-homojunction (p-SnO/n-SnO2) and compare it to a p-SnO/n-ZnO heterojunction structure in term of their rectification behavior. XPS measurements reveal that both SnO2 and ZnO at the Γ point exhibit a type II band offset with SnO with their respective valence band (conduction band) offset of 2.8 eV (1.9 eV) and 2.4 eV (1.33 eV). On the other hand, the indirect conduction band minimum of SnO shows a type I band offset in both junctions with a small conduction band offset of ∼0.1–0.17 eV. The SnO/SnO2 p-n structure shows a reasonable rectification with an ideality factor of ∼12.3, which can be potentially useful in many transparent p-n junction based devices.

Influence of metal doping and non-metal loading on photodegradation of methylene blue using SnO2 nanoparticles

Pure SnO2, Zn (0.075 M) doped SnO2 loaded corn cob activated carbon (Zn: SnO2/CCAC) were synthesized by a chemical precipitate process. The influence of Zn doped and CCAC loaded on the crystallite structure, optical, morphology, and photocatalytic properties of pure SnO2 were investigated. The XRD patterns confirmed that Zn doped SnO2 with loaded CCAC sample exhibited a rutile tetragonal structure. The XPS survey confirmed that the Zn ion was incorporated into the SnO2 lattice with a Zn2+ oxidization state. The band gap value of Zn: SnO2/CCAC was reduced (3.48 eV) as compared to pure SnO2 and doped samples. Further, the reduced PL emission intensity of Zn: SnO2/CCAC and its reduced resistance value of impedance from EIS analysis, and the enhanced separation of the photogenerated e−/h+ pairs support the enhanced photodegradation efficiency. The Zn: SnO2/CCAC sample showed improvement in the photodegradation efficiency (98.61 %) of methylene blue (MB) as compared to pure SnO2 and Zn: SnO2, respectively.

Silver doped ZnSnO3/SnO hybrid nanostructures as DSSC photoanodes: Charge injection dynamics, slow recombination kinetics and simulation studies

Sol-gel synthesis was used to develop a new hybrid photoanode material, a spherical zinc stannate/tin oxide nanorod named ZSTP. The subsequent step involves doping ZSTP with silver using a precursor called silver nitrate. The undoped sample was labelled as ZSTP, whereas silver-doped composites containing 1, 2, and 3 wt% silver were labelled as ZSTP-Ag1, ZSTP-Ag2 and ZSTP-Ag3 respectively. The pattern of powder X-ray diffraction (PXRD) with 2θ values of 26.52 and 33.84 confirms the orthorhombic structure of ZSTP and silver-doped samples. In the FT-IR spectra of the ZSTP and their silver-doped samples, the stretching frequency for Zn–O–Sn is observed at 1100 and 1464 cm−1. In addition, the surface-adsorbed Ag peaks at 1384 cm−1. The XPS spectra of ZSTP-Ag3 confirms the existence and structure of SnO and Ag. Examining the morphology with a scanning electron microscope (SEM) and transmission electron microscope (TEM) reveals a porous structure with adsorbed Ag on the surface. Doped silver appears as tiny spherical particles on the surfaces, whereas SnO nanorod zinc stannate appears as spherical particles in the TEM image. In-depth optical experiments were conducted to evaluate the characteristics of hybrid composites for DSSC applications. It was explored how the dye aggregates on the surface of silver-doped ZSTP. On the basis of the energy levels of their conductance bands, the electron transfer kinetics and energy transfer mechanism were predicted. Under a conventional one-sun illumination condition, the output photocurrent and photovoltage of these DSSC materials are evaluated. ZSTP-Ag3 offered the highest PCE at 1.38%. Due to the role of Ag2O in electron transfer, silver doped samples based devices offer a high FF (0.7) and steady photovoltage. Using the photovoltage decay curve, the recombination time (τrec) and rate (krec) were calculated to confirm a slower rate of recombination. Using simulated results, the overall performance of the DSSC is compared and validated.

Insight into Copper Doping Ratio on Optoelectronics Performance of Two-Dimensional Cu-Doped SnO2 Nanosheets: an Experiment and DFT Study

The optoelectronics performances of two-dimensional Cu-doped SnO2 nanosheets were investigated by first-principles calculations on the basis of density functional theory (DFT) and experiments. First, the crystal structures of Cu-doped SnO2 were built and analyzed by using DFT within the generalized gradient approximation (GGA). The total energy of Cu-doped SnO2 was discussed qualitatively and quantitatively from three aspects: charge density, band structure, and state density. The results show that copper doping has little effect on the charge density distribution because of the similar ionic radius of Cu2+, Sn4+, and the close bond lengths of Cu–O and Sn–O. The calculation results of band structure and state density show that the doping of a copper acceptor leads to the appearance of a new energy level at the top of the valence band and decreases the band gap of SnO2. With the guidance of theoretical calculation, the nanosheets of Cu-doped SnO2 are constructed experimentally, and their optoelectronics performances are investigated. The experimental results exhibit that the Cu atom replaces the Sn atom in the SnO2 lattice, while the Cu-doped SnO2 retains the original rutile phase of the intrinsic SnO2. The sample with a doping ratio of 12.5% has more uniform particle morphology and dispersion characteristics. In addition, the 12.5% Cu-doped SnO2 obtained the largest transient photocurrent of 3 μA/cm2 and the lowest resistance to charge transfer, thereby indicating that the material has a remarkably higher optoelectronics performance under this ratio. The theoretical calculation and experimental results are consistent, which indicates that Cu doping effectively enhances the charge transfer in SnO2 and enables it for high-quality application in optoelectronic catalysis.

All-Printed Roll-to-Roll Perovskite Photovoltaics Enabled by Solution-Processed Carbon Electrode.

Perovskite photovoltaics have shown great promise in device efficiency but also the promise of scalability through solution-processed manufacture. Efforts to scale perovskites have been takenthrough printable mesoporous scaffolds and slot die coating of flexible substrates roll-to-roll (R2R). However, to date there has been no demonstration of entirely R2R-coated devices due to the lack of a compatible solution-processable back electrode; instead,high-value evaporated metal contacts are employed as a post process. Here, in this study, the combination of a low-temperature device structure and R2R-compatible solution formulations is employed to make a fully R2R printable device architecture overcoming interlayer incompatibilities and recombination losses. Therefore, the n-i-p device structure of SnO2 /perovskite/poly(3,4-ethylenedioxythiophene)/carbon is employed to form an ohmic contact between a p-type semiconductor and printable carbon electrode. In particular, the results show that the small-scale device efficiencies of 13-14% are achieved, matching the device performance of evaporated gold electrodes. Also, this entirely R2R-coated perovskite prototype represents a game changer, reaching over 10% (10.8) stabilized power conversion efficiency with unencapsulated long-term stability retaining 84% of its original efficiency over 1000 h under 70% RH and 25 °C.

Temperature and Ambient Band Structure Changes in SnO2 for the Optimization of Hydrogen Response

Tin dioxide (SnO2) is one of the most used materials for sensing applications operating at high temperatures. Commonly, “undoped SnO2” is made by precursors containing elements that can have a deleterious impact on the operation of SnO2 sensors. Here, we employ experimental and theoretical methods to investigate the structural properties and electronic structure of the rutile bulk and surface SnO2, focusing on unintentional doping due to precursors. Unintentional doping from precursors as well as intrinsic doping can play an important role not only on the performance of gas sensors, but also on the properties of SnO2 as a whole. The theoretical calculations were performed using density functional theory (DFT) with hybrid functionals. With DFT we examine the changes in the electronic properties of SnO2 due to intrinsic and unintentional defects and we then discuss how these changes affect the response of a SnO2-based gas sensor. From an experimental point of view, we synthesized low-cost SnO2 thin films via sol–gel and spin-coating processes. To further enhance the performance of SnO2, we coated the surface with a small amount of platinum (Pt). The crystalline structure of the films was analyzed using x-ray diffraction (XRD) and scanning electron microscopy (SEM), while for the determination of the elements contained in the sample, X-ray photoelectron spectroscopy (XPS) measurements were performed. Furthermore, we investigated the effect of temperature on the band structure of SnO2 in air, in a vacuum and in nitrogen and hydrogen chemical environments. To optimize the response, we used current–voltage characterization in varying environments. The aim is to associate the response of SnO2 to various environments with the changes in the band structure of the material in order to gain a better understanding of the response mechanism of metal oxides in different pressure and temperature environments. We found that the resistance of the semiconductor decreases with temperature, while it increases with increasing pressure. Furthermore, the activation energy is highly affected by the environment to which the thin film is exposed, which means that the thin film could respond with lower energy when exposed to an environment different from the air.

Regulation of structural, electrical and optical properties of Sb-doped SnO2 films prepared with different O2 flow rates by rapid thermal annealing

Effects of rapid thermal annealing (RTA) on the structure and photoelectric properties of Sb-doped SnO2 (ATO) films have not been systematically reported. In this study, ATO films were prepared by RF magnetron sputtering under different O2 flow rates (0, 15, 30 and 45 sccm), and then were subjected to RTA at different temperatures (400, 600 and 800 °C) in atmospheric environment. The results show that preferred orientations of ATO films changes from (101) to (110) crystal-plane and crystallite size increases with increasing O2 flow rate. RTA cannot change the films’ preferred orientation and crystallite size except for the film deposited in Ar atmosphere (0 sccm O2), but it can decrease the compressive stress in the films. The as-deposited and annealed films with low transmittance in visible light range (TVis) have obvious Raman scattering peak, and scattering peak of Eg vibration mode is stronger in the appearing Raman scattering peaks. Increasing O2 flow rate degrades electrically conductive properties of the films, increases TVis and makes optical band-gap (Eopt) first increase and then decrease. With increasing RTA temperature, the electrically conductive properties enhance and Eopt increases for the films deposited with all O2 flow rates, but TVis basically decreases for the films deposited with O2 flow rate of 15–45 sccm. Currently, the ATO film deposited at 15 sccm O2 and annealed at 600 °C has the best transparent conductive properties (the resistivity, sheet resistance, TVis and figure of merit are 2.09 × 10−3 Ω cm, 67 Ω/sq., 77.12%, and 1.11 × 10−3 Ω−1, respectively). In addition, element chemical states and point defects in the films were analyzed by XPS. Meanwhile, influence mechanisms of O2 flow rate and RTA on structure and properties of the films were discussed.

SnO2 coated carbon nanospheres: Facile preparation and electrochemical performances as anode materials for lithium ion batteries

In this work, the SnO2/C nanocomposites as the anode material for lithium ion batteries (LIBs) were successfully prepared by ultrasonic dispersing of the hydrothermally-synthesized carbon nanospheres in SnCl2 solution and aging for a period of time and then calcination of the dried intermediates in an inert atmosphere. As demonstrated by the experimental results, the obtained SnO2/C nanocomposites were composed of SnO2 nanocrystals (∼10 nm) coated uniformly on the surface of amorphous carbon nanospheres with diameters ranging from 200 nm to 240 nm. The electrochemical test results show that the prepared SnO2/C nanocomposites exhibited higher reversible capacity than the carbon nanospheres, and better cycling performance than the SnO2 nanocrystals. The enhanced electrochemical performance of SnO2/C nanocomposites could be due to the fact that the coupling of SnO2 nanocrystals and carbon nanospheres could not only effectively improve the mobility of charge carriers, but also effectively inhibit the collapse of the SnO2 structure at the expense of a part of the capacity, thus resulting in better structural stability of the SnO2/C nanocomposites.

Intercalated chitosan-ionic liquid ionogel in SnO nanoplate: band gap narrow and adsorption-photodegradation process

Ionogels are a category of hybrid material containing ionic liquid stabilized by polymeric network. These composites have some applications in solid-state, energy storage devices and environmental studies. In this research, chitosan (CS), ethyl pyridinium iodide ionic liquid (IL), and ionogel (IG) consisting of chitosan and ionic liquid were used in the preparation of a SnO nanoplate (SnO-IL, SnO-CS and SnO-IG). For the preparation of the ethyl pyridinium iodide, a mixture of pyridine and iodoethane (1: 2 molar ratio) was refluxed for 24 hours. The ionogel was formed using ethyl pyridinium iodide ionic liquid in chitosan that was dissolved in acetic acid (1 % v/v). By increasing NH3∙H2O, the pH of the ionogel reached 7‐8. Then, the resultant IG was mixed with SnO in an ultrasonic bath for 1 h. The microstructure of the ionogel was involved as assembled unit via π-π, electrostatic and hydrogen bonding interactions to be three-dimensional networks. The intercalated ionic liquid and chitosan influenced the stability of the SnO nanoplates and improved band gap values. When chitosan was contained as the interlayer space of the SnO nanostructure, the resulting biocomposite formed a well-ordered flower-like SnO structure. These hybrid material structures were characterized by FT-IR, XRD, SEM, TGA, DSC, BET, and DRS techniques. The changes in the band gap values for photocatalysis applications were investigated. In the case of SnO, SnO-IL, SnO-CS, and SnO-IG, the band gap energy was 3.9, 3.6, 3.2, and 2.8 eV, respectively. The dye removal efficiency of SnO-IG was 98.5, 98.8, 97.9, and 98.4 % via the second-order kinetic model for Reactive Red 141, Reactive Red 195, Reactive Red 198, and Reactive Yellow 18, respectively. The maximum adsorption capacity of SnO-IG was 540.5, 584.7, 1501.5, and 1100.1 mg/g for Red 141, Red 195, Red 198, and Yellow 18 dyes, respectively. Also, an acceptable result (96.47 % dye removal) was obtained with the prepared SnO-IG biocomposite for dye removal from textile wastewater.

The cationic interstitials induced resistive switching: a case study on Mn-doped SnO2

This work has explored the possible defects in Mn-doped SnO2 and compared the effects of interstitial Mn and oxygen vacancies on the electronic structure of SnO2. Combining the DFT calculations and experimental measurements, we found that when the Mn-doped SnO2 is synthesised under Sn-rich or O-poor conditions, the defect pair of Mn substitution and interstitial rather than oxygen vacancy will be formed, which induces energy band across the Fermi level and significantly affects the electronic structure of SnO2. With the Mn interstitials, stable intrinsic multi-level resistive states and optical SET can be achieved in the Mn-doped SnO2 memristors. This result can provide guidance in the fabrications of defective metal oxides and promote the investigations on cationic interstitial triggered multi-level resistive switching and optoelectronic memristors.

Effect on Optical and Antibacterial Activity of SnO&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt; and CuO Blended SnO&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt; Nanoparticles

Nanocrystalline SnO2 and CuO doped with SnO2 were prepared by the co-precipitation method and characterized for different physiochemical properties and microbiological activity. The composition and morphological formation were characterized by XRD, HRTEM, Raman, FTIR, and UV-vis spectroscopy. The Powder X-ray analysis reveals that Sn4+ ions have substituted the Cu2+ ions without changing the monoclinic structure of SnO2 but the average particle size of the SnO2 and CuO doped SnO2 samples from 11 and 5 nm respectively. However, it exhibits an inhibiting strong bacterial growth against tested bacterial strains.

Integrated structure design and synthesis of a pitaya-like SnO2/N-doped carbon composite for high-rate lithium storage capability.

Tin dioxide (SnO2) with a high theoretical capacity of 1494 mA h g-1 has great potential to break through the capacity limitation of the conventional graphite anode (372 mA h g-1) in lithium-ion batteries. However, its practical application still faces several obstacles such as high volumetric expansion and poor electrical conductivity. To solve these problems, innovative design and synthesis of SnO2-based nanocomposite structures are necessary. Herein, we demonstrate an integrated design of a hierarchical pitaya-like P-SnO2/C@NC core-shell nanostructure which includes the core of SnO2 nanoparticles (∼4-12 nm) uniformly embedded in the porous carbon sphere and the shell of a continuous nitrogen-doped carbon (NC) layer. Specifically, during repetitive lithiation and delithiation processes, the ultrasmall SnO2 nanoparticles reduce the internal stress greatly, the porous carbon matrix provides buffer space for a large volume change, and the N-doped carbon shell further guarantees the whole structure unit sufficient electrical conductivity and structural stability. Consequently, the resultant battery exhibits a reversible capacity of 936.8 mA h g-1 after 100 cycles at 100 mA g-1 and even an average capacity of 460.0 mA h g-1 at a high current density of 3.2 A g-1. The excellent electrochemical performance of pitaya-like SnO2/C@NC proves the efficacy of this structure design and thus provides significant reference for the construction of other electrode materials in rechargeable alkali metal ion batteries.

Electronic and Thermoelectric Properties on Rutile SnO2 Under Compressive and Tensile Strains Engineering

SnO2 has the potential to be an environmentally friendly thermoelectric material. To obtain the optimum properties of this material, strain engineering is used to investigate the electronic and thermoelectric properties. In this study, we used compressive and tensile strains with -5%, -2%, 0%, 2%, 5%, and 10% in three schemes; they are triaxial (ɛabc), biaxial (ɛab), and uniaxial (ɛc) strains. All model structures are calculated based on density functional theory (DFT) with several exchange-correlation functionals. The presented results show that strain engineering enhances the Seebeck coefficient for a compressive strain parameter since the energy gap between the conduction and valence band increased due to the strong covalent bonding at the conduction band. From several comparisons in bandgap and thermoelectric properties calculation between PBEsol and PBE0, this study suggests that PBE0 is effectively used to calculate the energy gap. Meanwhile, for thermoelectric properties, PBEsol gave the best-estimated value. In addition, this study explained that the largest or the smallest bandgap could be achieved by varying strain simply on the c-axis as the optimum manipulation of the SnO2 structure. Furthermore, this paper also revealed that the simulation strategy could be determined from the desired result, whether to enhance the Seebeck coefficient or the electrical conductivity by manipulating the ab-axis and the c-axis, respectively.

Effect of dopant concentration Mn in SnO2 nanoparticles on photocatalytic, magnetic and optical properties

Mn doped SnO2 nanoparticles were synthesized in a sol-gel technique at various concentrations. A wide range of properties are analyzed by using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy with energy dispersive spectroscopy (SEM with EDAX), Transmission Electron Microscopy (TEM), UV-Visible spectroscopy, photoluminescence spectroscopy (PL), Vibrating Sample Magnetometer (VSM), and photocatalytic studies. Results from EDAX confirmed the presence of Sn and Mn ions in SnO2 nanoparticles doped with Mn. As a result of analyzing the luminescence of all synthesized samples, blue emission characteristic of lighting applications was observed. Furthermore, 0.2M Mn doped SnO2 sample shows the enhanced ferromagnetism at room temperature with elevated saturation magnetization value. The 0.2M Mn doped SnO2 nanoparticles show the significant increase in photocatalytic efficiency of SnO2 among the other doped samples. Thus, all experiment results demonstrated that the concentration of dopant influences the structure, optical properties, photocatalytic properties, and magnetic properties of SnO2.

Preserved crystal phase and morphology: Improving the magnetic and electrochemical performance of sulfur doped tin oxide nanoparticles synthesized via the hydrothermal method

Herein, we report synthesis of bare and Sulfur (S) doped SnO2 nanoparticles (NPs) using simple and low cost hydrothermal method. S with different concentration (0, 2, 4 and 6) were doped in SnO2 and named as bare SnO2, 2%S:SnO2, 4%S:SnO2 and 6%S:SnO2, respectively. The synthesized NPs were characterized for structural, functional, optical, morphological, electrochemical and magnetic properties. XRD confirms the tetragonal structure of bare SnO2 2%S:SnO2, 4%S:SnO2 and 6%S:SnO2 NPs. The crystallite size and microstrain was calculated using the Scherrer equation, W-H plot, SSP plot, and H-W plot and are in well agreement with each other. The FTIR confirmed formation of S-O and Sn-O bonding. The direct energy band gap values of bare SnO2, 2%S:SnO2, 4%S:SnO2 and 6%S:SnO2 are 3.8 eV, 3.6 eV, 3.1 eV and 2.2 eV, respectively. The electrochemical performance (ECP) of bare SnO2 and 2%S:SnO2 NPs were studied by making their electrodes through CV, GCDs, and EIS measurements. The bare SnO2 and 2%S:SnO2 electrodes show the specific capacitance of 125 F/g and 225 F/g at a current density of 3 A/g proves S doping enhances the capacitive performance of SnO2 NPs. The VSM shows paramagnetic behavior changes into ferromagnetic behavior with S doping.

Comparative Study of Sonophotocatalytic, Photocatalytic, and Catalytic Activities of Magnesium and Chitosan-Doped Tin Oxide Quantum Dots.

The present study demonstrates the hydrothermal synthesis of SnO2 quantum dots (QDs) doped with different concentrations (2, 4 wt %) of magnesium (Mg) and a fixed amount of chitosan (CS). The obtained samples were investigated through a number of characterizations for optical analysis, elemental composition, crystal structure, functional group presence, interlayer spacing, and surface morphology. The XRD spectrum revealed the tetragonal structure of SnO2 with no significant variations occurring upon the addition of CS and Mg. The crystallite size of QDs was reduced by incorporation of dopants. The optical absorption spectra revealed a red shift, assigned to the reduction of the band gap energy upon doping. TEM analysis proved that the few nanorod-like structures of CS overlapped with SnO2 QDs, and agglomeration was observed upon Mg doping. The incorporation of dopants little enhanced the d-spacing of SnO2 QDs. Moreover, the synthesized nanocatalyst was utilized to calculate the degradation percentage of methylene blue (MB) dye. Afterward, a comparative analysis of catalytic activity, photocatalytic activity, and sonophotocatalytic activity was carried out. Notably, 4% Mg/CS-doped QDs showed maximum sonophotocatalytic degradation of MB in basic medium compared to other activities. Lastly, the prepared nanocatalyst was found to be efficient for dye degradation in any environment and inexpensive.