Band Gap Of SnO2 Research Articles

Investigating AgCl-SnO2 nanocomposite for photocatalytic degradation of azo dye, associated reaction pathways, and its antibacterial activity

Herein, AgCl-SnO2 nanocomposite (NC) fabricated through a facile hydrothermal method exhibit substantial potential as an efficient and economical photocatalyst and bactericidal agent. The formation of spherical AgCl-SnO2 NC was confirmed through PXRD and SEM, with an average crystalline size of 12 nm. DR spectra and Kubelka-Munk function were used to determine the band gaps of AgCl (3.10 eV) and SnO2 (3.48 eV). The synthesized NC achieve successful photocatalytic degradation (98 %) of orange-G (OG) dye within 60 min. The NC’s potential was also elucidated by investigating the role of sacrificial reagents. Formation of •OH free radicals is confirmed from photoluminescence studies using terephthalic acid. The effective degradation of OG dye has been substantiated, resulting in the generation of numerous intermediate products with reduced toxicity, such as substituted phenols and aromatic dicarboxylic compounds. Furthermore, the NC demonstrated excellent efficiency even after six consecutive cycles, indicating its stability, regenerative property, and recyclability. The NC also exhibits significant antimicrobial activity against Escherichia coli.

Enhanced diffusion kinetics in Y-doped SnO2 anodes for low-temperature lithium-ion batteries: A combined theoretical and experimental study

In recent years, there has been an increasing demand for lithium-ion batteries suitable for low temperatures in various fields. SnO2, with its high theoretical specific capacity, has emerged as an ideal candidate for low-temperature lithium-ion batteries. However, tin oxide exhibits inherent issues such as poor conductivity and limited cycle reversibility. Enhancing the diffusion rate of lithium ions in tin oxide is crucial for improving its low-temperature performance. We use first-principles calculations based on Density Functional Theory (DFT) to investigate the doping models of various transition metal elements (Sc, Y, Ti, Zr, V, Nb, Gr, Mo, Mn, Fe, Co, Ni) with a rational ratio of 4 % in SnO2. The results indicate that Y doping decreases the band gap of SnO2 by 0.253 eV, leading to a significant reduction in the Li-ion diffusion barrier of α-Sn. Furthermore, the synthesized SnO2 doped with Y (Y-SnO2) electrode exhibited excellent cyclic stability as an anode and achieved a high reversible capacity of 672 mAh g−1 at −10°C, surpassing that of the pure SnO2 (450 mAh g−1). Moreover, it demonstrated a higher diffusion coefficient of lithium ions and lower charge transfer impedance at both low and room temperatures.

Thermodynamic, electronic, and optical properties of ultra-wide bandgap zirconium-doped tin dioxide from a DFT perspective.

The effects of zirconium doping on the thermodynamic, electronic, and optical properties of tin dioxide are investigated by using density functional theory calculations combined with the cluster expansion method. In the whole composition range, the formation enthalpies of all structures are positive, indicating that SnO2-ZrO2 is an immiscible system and the ZrSnO2 alloy has a tendency of phase separation at low temperature. The x-T phase diagram of ZrSnO2 ternary alloy shows that the critical temperature is 979 K, which means that when the growth temperature of ZrSnO2 crystal is higher than the critical temperature, it is possible to realize the full-component solid solution. The bandgaps of ZrxSn1-xO2 alloys (0 ≤ x ≤ 1) are direct and increase as the Zr composition increases. Zr doping can tune the bandgap of SnO2 from the ultraviolet-B region to the deep ultraviolet region, and has a strong optical response to deep ultraviolet light. The projected density of states and band offsets clearly reveal the reason for the increase of bandgap, which provides useful information to design relevant optoelectronic devices such as quantum wells and solar-blind deep ultraviolet photodetectors.

Vanadium and tantalum doping of tin dioxide: a theoretical study.

The increasing demand of efficient optoelectronic devices such as photovoltaics has created a great research interest in methods to manipulate the electronic and optical properties of all the layers of the device. Tin dioxide (SnO2), due to his charge transport capability, high stability and easy fabrication is the main electron transport layer in modern photovoltaics which have achieved a record efficiency. While the wide band gap of SnO2 makes it an effective electron transport layer, its potential for other energy applications such as photocatalysis is limited. To further improve is conductivity and reduce its bandgap, doping or co-doping with various elements has been proposed. In the present density functional theory (DFT) study, we focus on the investigation of vanadium (V) and tantalum (Ta) doped SnO2 both in the bulk and the surface. Here we focus on interstitial and substitutional doping aiming to leverage these modifications to enhance the density of states for energy application. These changes also have the potential to influence the optical properties of the material, such as absorption, and make SnO2 more versatile for photovoltaic and photocatalytic applications. The calculations show the formation of gap states near the band edges which are beneficial for the electron transition and in the case of Ta doping the lowest bandgap value is achieved. Interestingly, in the case of Ta interstitial, deep trap states are formed which depending of the application could be advantageous. Regarding the optical properties, we found that V doping significantly increases the refractive index of SnO2 while the absorption is generally improved in all the cases. Lastly, we investigate the electronic properties of the (110) surface of SnO2, and we discuss possible other applications due to surface doping. The present work highlights the importance of V and Ta doping for energy applications and sensor applications.

Structural, optical, and dielectric properties of M/SnO2 (M= Al2O3, NiO, Mn3O4) nanocomposites

The structural parameters, optical properties, and dielectric constants at a frequency (f) range of 0.1–20 MHz, and temperature (T) range of 300–400 K of hydrothermally synthesized M/SnO2 nanocomposites (for simplicity M denotes oxides of Al, Ni, or Mn) were compared. Rietveld refined X-ray powder diffraction (XRD) analysis demonstrated the formation of hexagonal, cubic, or spinel crystal structures of Al2O3, NiO, or Mn3O4 phases, respectively, besides the tetragonal rutile crystal structure of SnO2. The impact of Al addition on the optical band gap of SnO2 is negligible while it decreased or increased by incorporation of Ni or Mn, respectively. The residual lattice dielectric constant of SnO2 was increased, while the real part of the dielectric constant and the ac conductivity of SnO2 were decreased by M incorporation. The dielectric parameters are remarkably affected by selected M, T, and f values and their changes agree with the Maxwell-Wagner model. The Q-factor of SnO2 was increased by M addition while decreased with increasing T. The Ni/SnO2 obeys the hole conduction at T ≤ 330 K, while Mn/SnO2 and Ni/SnO2 obey the electronic conduction at T > 330 K. The binding energy is independent of the chosen T for SnO2, whereas it sharply increases for Ni/SnO2 and slightly decreases for Al/SnO2 and Mn/SnO2. The F-factor of SnO2 was slightly decreased by M addition, but it was increased with T for SnO2, Al/SnO2, and Mn/SnO2 while was decreased for Ni/SnO2. The Cole-Cole plots for M/SnO2 composites were analyzed, and the components of the equivalent circuit were determined. The electrical impedance, resistance of grains, resistance of grain boundaries, and equivalent resistance of SnO2 were increased by M incorporation, whereas equivalent capacitance was decreased. The findings recommend the SnO2-based nanocomposites for applications in optoelectronics, lithium batteries, supercapacitors, and solar cell devices.

Single step facile synthesis of Cu-SnO2/ZnO nanocomposite photocatalyst for methylene blue dye degradation in aqueous solution

A Cu-SnO2/ZnO nanocomposite was prepared using a single-step facile synthesis method, sol–gel, for photocatalyst application. The XRD of Cu-SnO2/ZnO nanocomposite shows SnO2 and ZnO have tetragonal rutile and hexagonal wurtzite, which is similar to HRTEM and SAED data. The crystallite sizes of SnO2, ZnO, Cu-SnO2, SnO2/ZnO, and Cu-SnO2/ZnO are 8.50 nm, 29.12 nm, 7.10 nm, 6.42 nm, and 3.50 nm, respectively. The calculated energy band gap of SnO2, ZnO, Cu-SnO2, and Cu-SnO2/ZnO from the DRS measurements is 3.60 eV, 3.20 eV, 3.34 eV, 3.48 eV, and 3.09 eV, respectively. The photoluminescence spectroscopy shows that Cu-SnO2/ZnO nanocomposite has a higher defect density than another sample. The Fourier Transform Infrared (FTIR) spectroscopy identifies the functional groups of the Cu-SnO2/ZnO powder samples. The EDS spectra of the synthesized Cu-SnO2/ZnO nanocomposite indicated the existence of the elements of Cu, Sn, Zn, and O, respectively. The photocatalyst activities of Cu-SnO2/ZnO have higher efficiency, ~78%, than other samples.

Synthesis and properties of alkaline earth elements (Ca, Sr, and Ba) doped SnO2 thin films

Transparent conductive oxides (TCOs) are commonly used in many optoelectronic, photovoltaic, and catalytic applications because of their unique optical transparency and electrical conductivity. In this work, we report, for the first time, on the optical and electrical properties of Ca-doped tin thin films, and we shed more light on the structure and properties of Sr- and Ba-doped SnO2 thin films. A simple and low-cost spray pyrolysis technique (SPT) was used to synthesize SnO2 thin films doped with alkaline earth elements (Ca, Sr, and Ba) that have ionic radii larger than tin ion radius. The microstructural features of the prepared samples were investigated using a scanning electron microscope, an atomic force microscope, and an x-ray diffractometer. The presence of the dopants and relevant chemical bonds were ascertained through Fourier Transform-Infrared (FT-IR) spectroscopy. The optical and electrical properties were characterized using a spectrophotometer and a four-point probe analyzer, respectively. The synthesized thin films were polycrystalline and had a tetragonal rutile structure with preferred growth orientation along <110> direction. Doping with Ca increased the crystallite size and decreased the dislocation density and micro strain, whereas opposite trend was observed for samples doped with Sr and Ba. The films had smooth, dense, continuous, and homogenous surface. FT-IR analysis revealed the presence of O–Sn–O, Ca–O–Ca, Ba–O and Sr–O bonds. Doping SnO2 with Ca, Sr and Ba improved its optical transmittance from 67% to around 82%. The band gap of pure SnO2 (3.57 eV) decreased to 3.08 and 3.05 eV as a result of doping with Ca and Sr, respectively; and increased to 3.60 eV because of doping with Ba. Strontium and calcium increased the electrical conductivity of SnO2 from 5.79 (Ω cm)−1 to 36.24 and 56.11 (Ω cm)−1, respectively; but barium decreased it to 2.45 (Ω cm)−1. The relatively wide energy gap, high electrical conductivity, and high transmittance of the Ca- and Sr-doped films make them good candidates in diverse functional applications.

Antibacterial activity of SnO2 in visible light enhanced by erbium–cobalt co-doping

In this work, a series of SnO2 samples with systematically varied doping amounts of Er and Co were prepared via a precipitation–hydrothermal method. The results show that after Er doping, the 4I15/2 ground state of Er3+ jumps to the 4H11/2 higher-energy level, and the Er-doped SnO2 samples can efficiently convert low-energy light into high-energy light. Thus, Er doping is beneficial for improving the visible and near-infrared light response of SnO2 and thus enhances its photocatalytic performance. Furthermore, doping SnO2 with Co leads to a distortion of the SnO2 lattice. A proportion of the SnO2 lattice is replaced by Co atoms, which can effectively lower the bandgap of SnO2, widen its optical response range, and enhance its sunlight absorption efficiency. The photocatalytic antibacterial activities of pure SnO2, as well as SnO2 co-doped with Er and Co in visible light, were investigated under visible light using Escherichia coli. SnO2 shows the best antibacterial activity and electron–hole separation efficiency when co-doped with 1.5 mol. % Er and 1.5 mol. % Co (Er1.5Co1.5-SnO2). Gradient experiments reveal that mainly the reactive oxygen species affect the antibacterial activity of pure SnO2. The improved antibacterial performance of Er1.5Co1.5-SnO2 is attributed to the increased generation of·O2− and·OH. In addition, scavenger experiments reveal that·O2− is the key contributor to the enhanced antibacterial activity of SnO2.

Analyzing the role of Ni dopant to change the structural, optical and photocatalytic properties of SnO2 nanoparticles

SnO2 and 5 wt% Ni doped SnO2 nanoparticles (SnO2:Ni NPs) were successfully synthesised by a template-free hydrothermal method. X-ray diffraction (XRD) patterns depicted polycrystalline nature of the NPs in rutile-type cassiterite phase with dominant (110) and (101) Bragg diffraction peaks. Rietveld refinement of XRD patterns supported single phase tetragonal crystal structure having space group P42/m n m. With Ni doping, crystallite size of NPs decreased from 39 nm to 35 nm whereas lattice strain increased from 3.56 × 10−3 to 3.99 × 10−3. This is attributed to the substitution of Sn4+ ion by Ni2+ ions. The morphology of the SnO2 NPs also changed from regular spherical shape to elongated irregular shape upon Ni doping. The dominant Raman peak obtained at 634 cm−1 matched with the signature peak for rutile SnO2 (Raman A1g mode). Further, we observed disappearance of E g mode due to Ni doping, which indicated the formation of oxygen vacancies. Also, XPS analysis indicated an increase of oxygen vacancy concentration in the doped NPs due to charge imbalance between Sn4+ and Ni2+. The direct optical band gap of SnO2 increased from 3.97 eV to 4.11 eV when doped with 5 wt% Ni and it is ascribed to Burstein–Moss effect. Irrespective of higher optical band gap of SnO2:Ni NPs, they showed enhanced photocatalytic activity to degrade Rhodamine B (RhB) dye molecules under UV-visible irradiation. The first order kinetic reaction rate constants for degradation of RhB were found to be 0.014 min−1 and 0.045 min−1 in case of SnO2 and SnO2:Ni NPs respectively. The enhanced photocatalytic activity in SnO2:Ni NPs is explained by relating to the formation of more oxygen vacancies and chemisorptions of O2 and H2O molecules followed by generation of radicals. This work demonstrates the superiority of SnO2:Ni NPs for use as photocatalytic material for industrial waste water treatment.

Tailoring SnO2 Defect States and Structure: Reviewing Bottom-Up Approaches to Control Size, Morphology, Electronic and Electrochemical Properties for Application in Batteries.

Tin oxide (SnO2) is a versatile n-type semiconductor with a wide bandgap of 3.6 eV that varies as a function of its polymorph, i.e., rutile, cubic or orthorhombic. In this review, we survey the crystal and electronic structures, bandgap and defect states of SnO2. Subsequently, the significance of the defect states on the optical properties of SnO2 is overviewed. Furthermore, we examine the influence of growth methods on the morphology and phase stabilization of SnO2 for both thin-film deposition and nanoparticle synthesis. In general, thin-film growth techniques allow the stabilization of high-pressure SnO2 phases via substrate-induced strain or doping. On the other hand, sol-gel synthesis allows precipitating rutile-SnO2 nanostructures with high specific surfaces. These nanostructures display interesting electrochemical properties that are systematically examined in terms of their applicability to Li-ion battery anodes. Finally, the outlook provides the perspectives of SnO2 as a candidate material for Li-ion batteries, while addressing its sustainability.

SnO2-Cu2S nanocomposites: Structural and optical properties with enhanced photocatalytic activities for ciprofloxacin antibiotic and methylene blue dye degradation

Pharmaceutical products and industrial dyes released to water bodies have become major environmental concerns and applications of nanomaterials for their remediation have been receiving a lot of research attention in recent years. In this connection, different SnO2–Cu2S nanocomposites (NCs) have been synthesized by growing Cu2S over previously prepared SnO2 nanocrystals by taking different molarities of copper and sulphur precursors. The pure SnO2 nanocrystals have been prepared by the chemical co-precipitation method combined with calcination of the precipitated materials at 300 °C. X-ray diffraction (XRD) pattern of the pure SnO2 nanocrystals shows the formation of tetragonal crystal structure. UV–visible–NIR absorption spectrum of the pure SnO2 nanocrystals records absorption peak in the UV region, while the Tauc's plot estimates the band gap of SnO2 to be 3.93 eV. Photoluminescence (PL) and electron paramagnetic resonance (EPR) studies reveal the presence of oxygen vacancies in the pure SnO2 nanocrystals. XRD patterns of the NCs comprise of diffraction planes from both tetragonal SnO2 and monoclinic Cu2S. PL studies show presence of both oxygen vacancies and copper vacancies in the NCs. Further, presence of copper vacancies has been evidenced in the EPR signals of the NCs. The NCs show significantly enhanced photocatalytic activities for degradation of ciprofloxacin (CIP) antibiotic and methylene blue (MB) dye under simulated sunlight irradiation, which is attributed to type II heterojunction formation between SnO2 and Cu2S. The NC with the best performance as a photocatalyst degrades 96% of CIP after 120 min and 98% of MB after 210 min of light exposure.

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.

Comparative study of microstructural and optical properties of Sn0.95X0.05O2 (X = Mn, Cd)

Here, we have investigated the effect of dopants on the structural and optical properties of nanocrystalline SnO2. For this investigation, we synthesized Pure, Mn and Cd-doped SnO2 using the precipitation method. The structure and optical properties of prepared samples were studied using XRD and diffused reflectance spectroscopy. The reflectance spectroscopy demonstrated that the bandgaps of Mn and Cd doped SnO2 were calculated using Tauc’s plot and found to be slightly different from the bandgap of pure SnO2. The optical bandgap of Cd-SnO2, Mn-SnO2, and pure SnO2 are found to be 4.05 eV, 3.91 eV, and 4.03 eV, respectively.

The influence of different complexing agents on the properties of tin dioxide (SnO2) deposited thin films through chemical bath approach

The present study explores the effect of disodium ethylenediamine tetraacetic acid and triethanolamine as alternative complexing agents to synthesize SnO2 thin films by employing simplistic chemical bath deposition method. The as-deposited tin dioxide thin films have been characterized by various analytical techniques particularly X-rays diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive x-ray analysis (EDX), and Raman spectroscopy. The XRD and Raman spectroscopy reveal the crystalline nature pertaining small crystal grains of the as-deposited SnO2 thin films with a tetragonal rutile structure. The SEM analysis unfolds that as-synthesized thin films using disodium ethylenediamine tetraacetic acid and triethanolamine, the grains of the films exhibit different shapes. The bandgap energies of the films have been estimated from the absorbance spectra through Tauc plot and the respective optical band gap of SnO2-EDTA and SnO2 -TEA exhibits the values as ∼4.2 eV and ∼3.8 eV, respectively. These findings suggest as-deposited tin dioxide thin films to be pertinent for use in solar radiation absorption applications.

Anodic SnO2 Nanoporous Structure Decorated with Cu2O Nanoparticles for Sensitive Detection of Creatinine: Experimental and DFT Study.

Advanced anodic SnO2 nanoporous structures decorated with Cu2O nanoparticles (NPs) were employed for creatinine detection. Anodization of electropolished Sn sheets in 0.3 M aqueous oxalic acid electrolyte under continuous stirring produced complete open top, crack-free, and smooth SnO2 nanoporous structures. Structural analyses confirm the high purity of rutile SnO2 with successful functionalization of Cu2O NPs. Morphological studies revealed the formation of self-organized and highly-ordered SnO2 nanopores, homogeneously decorated with Cu2O NPs. The average diameter of nanopores is ∼35 nm, while the average Cu2O particle size is ∼23 nm. Density functional theory results showed that SnO2@Cu2O hybrid nanostructures are energetically favorable for creatinine detection. The hybrid nanostructure electrode exhibited an ultra-high sensitivity of around 24343 μA mM-1 cm-2 with an extremely lower detection limit of ∼0.0023 μM, a fast response time (less than 2 s), and wide linear detection ranges of 2.5-45 μM and 100 μM to 15 mM toward creatinine. This is ascribed to the creation of highly active surface sites as a result of Cu2O NP functionalization, SnO2 band gap diminution, and the formation of heterojunction and Cu(1)/Cu(ll)-creatinine complexes through secondary amines which occur in the creatinine structure. The real-time analysis of creatinine in blood serum by the fabricated electrode evinces the practicability and accuracy of the biosensor with reference to the commercially existing creatinine sensor. The proposed biosensor demonstrated excellent stability, reproducibility, and selectivity, which reflects that the SnO2@Cu2O nanostructure is a promising candidate for the non-enzymatic detection of creatinine.

Synergy of multi-means to improve SnO2 lithium storage performance achieved by one-pot solvothermal method

The high capacity and low operating potential made SnO2 very potential to be used as an anode material, but huge volume changes and poor conductivity defects hindered its practical application. Single improvement strategy had limited promotion on SnO2 lithium storage performance. Here, multi-strategy synergy effect of controlling the crystallinity to amorphous, reconstructing the band edge by Co, N co-doping and combining with graphene to enhance SnO2 electrochemical performances was achieved through a facile one-step solvothermal method. As-prepared cobalt and nitrogen co-doped amorphous SnO2/graphene composite ((Co, N)-a-SnO2/GR) possessed a high discharge specific capacity of 1694.4 mAh g−1 with an initial coulombic efficiency (ICE) of 70.1% at 0.5 A g−1, and good cyclic stability (1056.8 mAh g−1 after 400 cycles). The intrinsically isotropic and long-range disorder nature of the amorphous structure, the narrowing of the SnO2 bandgap caused by Co, N co-doping, and the introduction of graphene could synergistically improve the electrochemical performance of SnO2-based electrode. This kind of multi-ways synergy strategy also shed light on other similar anode materials.

Investigation of Cobalt Substitution on the Structural, Optical Band Gap, and Photocatalytic Dye Degradation Properties of Spray Deposited SnO2Thin Films

Pure and cobalt substituted tin oxide thin films are successfully formed on a glass substrate using the simple spray pyrolysis technique. XRD patterns reveal the polycrystalline nature of the samples with tetragonal rutile structure. The shift in X-ray diffraction peak to a higher 2θ value and its subsequent contraction of the SnO2 rutile lattice along the c-axis manifests the infusion of the guest cobalt ions. Crystallite size and microstrain values are found to vary with cobalt substitution. SEM analysis shows the uniform dispersion of the nanoparticles in the prepared thin films. The optical band gap values are found to narrow down with cobalt substitution from 4.04 eV–3.93 eV. Photoluminescence study hints at the presence of intermediate states within the forbidden energy band gap of SnO2. Photocatalytic dye degradation of Methylene blue (MB) highlights the role of cobalt with a high photocatalytic activity of 86 % compared to other investigated thin films.

MnO2-SnO2 Based Liquefied Petroleum Gas Sensing Device for Lowest Explosion Limit Gas Concentration

In this work, MnO2-SnO2 nanocomposite based below lower exposure limit (0.5–2.0 vol%) sensing device for liquefied petroleum gas (LPG) is reported. The synthesized material is highly crystalline with an average crystallite size of 16.786 nm, confirmed by the X-ray diffraction pattern. Williamson-Hall plot shows that the induced strain of 2.627 × 10−4, present in the nanocomposite, lies between the induced strains of both of its constituents. The XRD pattern of nanocomposite contains the cubic phase of MnO2 and the tetragonal phase of SnO2. Tauc plot shows the optical energy band gap of MnO2, SnO2, and MnO2-SnO2 of 3.407 eV, 3.037 eV, and 3.202 eV respectively. The surface morphological investigation shows the brush-like structure which enhances sensor performance by providing activation sites. The energy dispersive X-ray (EDS) spectrum found that materials are highly pure because other peaks are not observed. The functional group analysis by using FTIR found to be Sn–O and Mn–O both vibration bands existed. The highest sensor response was found to be 2.42 for 2.0 vol% whereas for a lower concentration of 0.5 vol% the sensor response was observed to be 1.44. The fast response and recovery of this sensing device were found to17.30 and 23.25 s respectively for 0.5 vol% of LPG.

Removal of Remazol Yellow Using SnO2-Co Photocatalyst

Remazol yellow is a synthetic dye that pollutes the environment and causes disease because it is carcinogenic and mutagenic. Photocatalyst is one of the technologies to remove the dye concentration, and tin oxide (SnO2) with cobalt (Co) dopant has the potential to be a good semiconductor in the process. Therefore, this study aims to synthesize SnO2/Co composites as a photocatalyst to degrade Remazol yellow dye. The photodegradation process was carried out with several variables, including the effect of time and the initial concentration of the dye and conditions under pHpzc. Furthermore, the composites were made with SnO to Co mass ratios of (2:1), (2:2), (2:3), and were characterized using X-Ray Diffraction (XRD), Scanning Electron Microscope-Energy Dispersive X-Ray (SEM-EDX), and Ultraviolet-Visible Diffuse Reflectance Spectroscopy (UV-Vis DRS) instruments. Based on the results, the SnO2/Co (2:3) composite was selected as a photocatalyst to degrade the dye as the XRD characterization showed the formation of a typical peak of 2θ at 33o. The energy bandgap of SnO2 is 3.05 eV, while the (2:3) composite had a value of 2.8eV. Moreover, the SEM characterization showed a non-uniform surface with pores and elements composition of Sn, O, and Co with the values 61.24, 24.67, and 14.09 wt%, respectively. The optimum condition for photodegradation was obtained at a contact time and concentration of 180 minutes and 10 ppm, respectively, while the removal of the dye reached 65-80%.

Investigation on structural and optical properties of porous SnO2 nanomaterial fabricated by direct liquid injection chemical vapour deposition technique

In the present study, Cassiterite SnO2 thin film synthesized by direct liquid injection chemical vapour deposition method. The surface morphology of the nanomaterial exhibited the rope-like structures with nanospheroid. Peak broadening in the prepared material is analyzed by Scherrer, modified Scherrer, Williamson-Hall, Size-strain and Halder-Wagner methods for investigation of crystallite size and intrinsic strain. The optical properties of the nanomaterial such as bandgap (Eg), absorption coefficient (α), skin depth (δ), optical density (Dopt), extinction coefficient (k), refractive index (n), and dielectric constants (εi and εr) are analyzed by using the UV–Visible transmittance and reflectance spectrum of the prepared SnO2 nanomaterial. The optical band gap of SnO2 based thin film was calculated by the Tauc plot and found to be 3.8 eV.