Co-doped SnO2 Research Articles

Impact on bandgap, electrical and magnetic properties of SnO2 nanoparticles by cerium and samarium

Synthesis of undoped, Samarium (Sm) and Cerium (Ce) co-doped SnO2 nanoparticles along with their enhancement in structural and physicochemical properties are reported. The samples have been prepared by co-precipitation method. The tetragonal rutile-type structure from PXRD pattern confirms the synthesized materials and obtained an average crystallite size of 23, 19 and 14 nm for the pure, 2 and 4 wt.% of Sm-Ce co-doped SnO2 NPs. The band at 620 cm−1 is assigned to the bonding of metal-oxygen as O-Sn-O bridging bond of SnO2 through FTIR-spectrum. From UV–DRS analysis, bandgap energy is found to be 3.45, 3.38 and 3.26 eV respectively for pure, 2 & 4 wt.% of Sm-Ce co-doped SnO2 NPs. Photoluminescence emission shows a sharp peak centered at 490 nm, a high intensity peaks at 521 and 538 nm due to blue and green emission. Addition of dopants narrowing the bandgap and reduces the dielectric constant as well as the dielectric loss. The dielectric constant and dielectric loss are directly proportional to temperature but inversely proportional to frequency, which shows that both polarizability and the method of charge transfer are impacted by the space charge polarization, which made the material could be a potential candidate in spintronics and high-performance dielectric materials. The effect of Sm-Ce co-dopants enhances the saturation magnetization value from 0.0049067 emu/g to 0.0072245 emu/g. The results exhibit that Sm-Ce (4 wt.%) co-doped SnO2 nanoparticles have strong dielectric and magnetic properties which is a potential candidate for spintronic devices.

High-Performance Tin Oxide Thin-Film Transistors Realized by Codoping and Their Application in Logic Circuits.

Tin oxide is a promising channel material, offering the advantages of being low-cost and environmentally friendly and having a wide band gap. However, despite the high electron mobility of SnO2 in bulk, the corresponding thin-film transistors (TFTs) generally exhibit moderate performance, hindering their widespread application. Herein, we proposed a codoping strategy to improve both the electrical property and the stability of SnO2 TFTs. A comparative analysis between doped and undoped SnO2 was conducted. It is observed that taking advantage of the difference in ionic radii between two dopants (indium and gallium) and the tin ions in the host lattice can effectively reduce impurity-induced strain. Additionally, we investigated the effect of codoping content on SnO2 TFTs. The optimal codoped SnO2 (TIGO) TFTs demonstrate high performance, featuring a field-effect mobility of 15.9 cm2/V·s, a threshold voltage of 0.2 V, a subthreshold swing of 0.5 V/decade, and an on-to-off current ratio of 2.2 × 107. Furthermore, the devices show high stability under both positive and negative bias stress conditions with a small threshold voltage shift of 1.8 and -1.2 V, respectively. Utilizing the TIGO TFTs, we successfully constructed a resistor-loaded unipolar inverter with a high gain of 10.76. This study highlights the potential of codoped SnO2 TFTs for advanced applications in electronic devices.

Zinc and [Zinc, Nickel]: Co‑doped SnO2 nanoparticles as prospective electron transport layer materials for efficient lead free-MASnI3 perovskite solar cells

In this study, we explore the potential of both pristine and doped tin oxide (SnO2) as promising materials as the electron transport layer (ETL) for efficient lead free-methylammonium tin iodide (MASnI3) perovskite solar cells (PSCs). The pristine, Zinc (Zn) doped, and Nickel (Ni)-Zn co-doped SnO2 nanoparticles with a constant concentration of Zn while changing the concentration of Ni were synthesized by using the hydrothermal method. The effect of doping and co-doping on optical, structural, and electrical properties of SnO2 nanoparticles was investigated using different microscopic and spectroscopic tools. The X-ray diffractograms showed that pristine, doped, and co-doped SnO2 nanoparticles have better crystallinity and tetragonal rutile crystal structure. The fingerprint functional groups and elemental composition were confirmed by FTIR absorption peaks, EDX, and XPS, respectively. The UV–Vis DRS spectroscopy results revealed that the optical band gap reduced from 2.90 eV for pristine SnO2 to 2.26 eV for co-doped 1 wt (wt) % Ni-Zn-SnO2 nanoparticles and can be tuned with a variation of wt % of Ni. Further, the photoluminescence emissions of all SnO2 nanoparticles in the range of 307 to 494 nm are related to oxygen vacancies or defects. Moreover, BET results confirms larger surface area for 1 wt % Ni-Zn-SnO2, which can help in better electron-hole pair separation. The electrical conductivity studies confirm that the synthesized nanoparticles exhibit excellent ohmic contact behavior and show a notable increase in electrical conductivity for 1 wt% Ni-Zn-SnO2 nanoparticles. Further, the suitability of both pristine and doped SnO2 as ETL material for the MASnI3-based PSCs was simulated using SCAPS-1D software. The best power conversion efficiency of 29.60 % was achieved for FTO/1 wt % Ni-Zn-SnO2/MASnI3/Spiro-OMeTAD/Au. This investigation highlights the potential of co-doped materials as promising candidates for the development of efficient PSCs.

Cobalt-doping-induced energy level and oxygen vacancy dual modulation in tin dioxide for efficient triethylamine detection

Highly sensitive triethylamine (TEA) gas sensors have undergone extensive research, yet slow response/recovery speed, poor moisture resistance, and high detection limitation limited their further application. Herein, pure SnO2 and Co-doped SnO2 nanofibers have been synthesized by a simple electrostatic spinning technique, and their sensing performance has been systematically analyzed. As a result, the sensors based on the 2 mol% Co-doped SnO2 nanofibers show a good response (Ra/Rg = 50.2) to 100 ppm TEA at 200 °C. In addition, the 2 mol% Co-doped SnO2 based sensors display a rapid response and recovery speed, low limit of detection, superior anti-humidity property, and excellent reproducibility for TEA. The improved sensing performance owing to enhanced chemisorbed oxygen as a consequence of the Fermi level regulation and the abundant oxygen vacancies. All in all, 2 mol% Co-doped SnO2 nanofibers have the potential for efficient detection of low concentrations of TEA.

Investigation on acceptor-donor co-doped SnO2 nanoparticles enriched with oxygen vacancies: a capacitive humidity sensor for respiration detection.

In this work, we develop a novel capacitive humidity sensor based on Al-Si acceptor-donor co-doped SnO2 for real-time monitoring of ambient humidity and human respiration. XRD measurements reveal that all samples exhibit a tetragonal rutile phase and the crystallite size of SnO2 decreases with increasing Al-Si content. The high intensity of the Raman peak at 762 cm-1 confirms the presence of bridging mode oxygen vacancies in (Al + Si)0.02Sn0.98O2. The EPR results show that the amount of singly ionized oxygen vacancies increases after the introduction of Al-Si. Both types and amounts of oxygen vacancy defects are particularly sensitive to the adsorption of water molecules. Moreover, according to DFT calculations, the contribution of the Si 3s orbital and Al 3s orbital to the band edge verifies the formation of acceptor-donor complexes in Al-Si co-doped SnO2. The humidity sensing results reveal that the (Al + Si)0.02Sn0.98O2 humidity sensor shows high sensitivity (S = 839), low hysteresis (1.94%) and fast response/recovery times (25 s/5 s). The respiratory intervals during shallow, medium and deep breathing states of (Al + Si)0.02Sn0.98O2 were measured at 2.8 s, 3.8 s and 4.5 s, respectively. The chemical mechanism for the enhancement of humidity sensing performance corresponding to the oxygen vacancy defects induced by Al-Si interplay is proposed.

Empirical correlation of ferromagnetism and electronic structure in Fe and Ni co-doped SnO2 solid solutions: An X-ray analysis using maximum entropy method

The phase-pure magnetic semiconducting Fex/2Nix/2Sn1-xO2 solid solutions with x = 0.03, 0.06, 0.09, and 0.12, were prepared by a cost-effective room-temperature one-step co-precipitation method. XRD peak red-shift reveals lattice compression due to the doping of low/similar ionic radii of Fe3+, Ni3+, and Ni2+ in the Sn4+ lattice, which is also confirmed by the EPR results. Maximum entropy method (MEM)-based electronic structure confirmed interstitial charge accumulation of 6.79 % and 6.05%, forming non-nuclear maxima in 3% and 12% doping systems, respectively, which reduces considerably the ferromagnetism. In addition, pure polar covalent apical and equatorial (Fe/Ni/Sn) – O bonding without interstitial charge accumulation is a key factor for maximum ferromagnetism. A perfect-fitting of the pair distribution function (PDF) and its correlation to charge accumulation at interstitial and regular lattice points in comparison with MEM results provides hope in PDF using low-Q XRD data. The samples with 9% and 6% dopants showed soft ferromagnetism with magnetization (0.0416 and 0.0372) emu/g respectively, which are helpful for magnetic semiconducting applications. The ferromagnetic and antiferromagnetic coupling between interstitial charges' local magnetic domains causes positive exchange anisotropy (exchange bias) in 3% and 12% compositions. The novel and empirical correlation between magnetism and the MEM-based electronic structure is the highlight of this study.

Ni-Co co-doped SnO2 nanomaterial coated polyurethane foam as a cost-efficient interfacial evaporator for solar steam generation

In this work, Nickel and cobalt (Ni-Co) are co-doped with Tin oxide (SnO2) to prepare 1 wt% co-doped SnO2, 3 wt% co-doped SnO2 and 5 wt% co-doped SnO2 nanomaterials (NCS-1, NCS-3 and NCS-5) respectively. It is then used in interfacial solar steam generation (ISSG). The evaporation rate and evaporation efficiency of NCS-3 coated polyurethane foam evaporator is 1.334 kg m-2h−1 and 83.62 %. From the observations, Ni-Co co-doped SnO2 nanomaterials performance is much higher than pure SnO2. The light absorbance abilities and band gap tuning of Ni-Co co-dopant can be attributed to the improved performance of ISSG. The long-term stability of NCS-3 sample is tested under 1 kW/m2. Eventually, all the samples have proven the ability to reduce the ion content in seawater and dye removal. We suggest Ni-Co co-doped SnO2 nanomaterial is a cost effective for energy conversion applications.

Effect of Cobalt Doping on Gas Sensing Properties of SnO2 Thick Films Prepared by Chemical Co-Precipitation Method

Co-precipitation method was used for the preparation of undoped SnO2 and n-type semiconductor nanomaterials of cobalt-doped SnO2. To identify the crystalline phase and morphology of the nanomaterials were characterized by X-ray powder diffraction and scanning electron microscopy. To focus and study on the gas sensing behaviour of undoped SnO2 and modified Co-doped SnO2 thick films. To study there sensitivity among the toxic, flammable and hazardous ethanol, hydrogen sulphide, nitrogen dioxide and ammonia gases. The optimum working temperature for the nanomaterial is same as per the variable gas sensitivity.

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

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

Enhanced degradation of refractory organics in ORR-EO system with a blue TiO2 nanotube array modified Ti-based Ni-Sb co-doped SnO2 anode

Recently, a novel 2-electron oxygen reduction reaction (ORR) based electro-oxidation (EO) system was developed, which utilizes a H2O2 generation cathode instead of H2 evolution cathode. A Ti-based Ni-Sb co-doped SnO2 (Ti/NATO) anode was selected for efficient degradation of refractory organics and O3 production. The synergistic reaction of O3/H2O2 further accelerated the generation of hydroxyl radicals (•OH) in the ORR-EO system. However, the catalytic activity and long-term effectiveness of the Ti/NATO anode limited the large-scale application of the ORR-EO process. In this study, a blue TiO2 nanotube array (blue-TiO2-NTA) inter-layer was introduced into the fabrication process between the Ti substrate and NATO catalyst layer. Compared to the Ti/NATO anode, the Ti/blue-TiO2-NTA/NATO anode achieved higher efficiency of organic removal and O3 generation. Additionally, the accelerated lifetime of the Ti/blue-TiO2-NTA/NATO anode was increased by 7 times compared to the Ti/NATO anode. When combined with CNTs-C/PTFE air cathode in ORR-EO system, all anodic oxidation and O3/H2O2 processes achieved higher •OH production. Over 92% of TOC in leachate bio-effluent was effectively eliminated with a relatively low energy cost of 45 kWh/t.

Cobalt ions doped SnO2 nanoparticles for enhanced photocatalytic and supercapacitor applications

Pure and Cobalt (Co)-doped SnO2 nanoparticles (NPs) were synthesized by a facile hydrothermal method. The SnO2 NPs were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscope (SEM), Energy dispersive spectra (EDS), High resolution transmission electron microscopy (HRTEM), UV –Visible spectroscopy (UV-Vis), Photoluminescence (PL) and X-ray photoelectron spectroscopy (XPS). The photocatalytic (PC) results of Co-doped SnO2 NPs showed a higher degradation efficiency than the pure SnO2 NPs. The electrode made of Co-doped SnO2 exhibited a maximum specific capacitance (Cs) of 317 F/g at the current density of 5A/g. The device gave the retention of 89.95% after 1000 continuous charge /discharge cycles. The experimental results demonstrated that the optimum concentration of Co-doped SnO2 NPs is an excellent bifunctional material for photocatalytic (PC) and supercapacitor (SC) applications

Electro-filtration efficient oxidation of herbicide atrazine by Sb, Ce co-doped SnO2 membranes

Electro-filtration efficient oxidation of herbicide atrazine by Sb, Ce co-doped SnO2 membranes

Optimisation of a Ce–Mn co-doped SnO2–Sb anode based on a nanotubular TiO2 array for electrochemical decolourisation of wastewater

ABSTRACT In this study, Ce and Mn co-doped SnO2–Sb electrode was prepared onto a Ti/TiO2 nanotubes surface. The nanostructure of the novel electrode was characterised by scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive spectroscopy (EDS), and specific techniques were used to study the electrochemical characteristics of the electrode. SEM analysis results showed that TiO2 nanotubes could reduce the crack morphology and provide a larger surface area for loading the electrochemically active material. EDS analysis showed that Ce and Mn were doped into the electrode successfully. Under optimised conditions, the electrode prepared with Sn:Sb:Ce:Mn mole ratio of 100:10:3:3 has the best electrocatalytic performance. Ethylene glycol was used as the solvent in cerium-manganese co-doped Ti/TiO2–NTs/TiO2–SnO2–Sb electrode. Ce–Mn co-doped TiO2NTs/SnO2–Sb electrode has a high oxygen evolution potential of 1.79 V (vs. SCE) and a lower charge transfer resistance. The decolourisation extent of 30 mg L−1 methylene blue wastewater reaches 98.5% within 30 min. Finally, the main intermediates were identified by gas chromatography-mass spectrometer (GC-MS), and possible pathways for dye degradation were proposed. This study opens a door to the rapid electrochemical decoloursation treatment of wastewater by using an easily obtainable multi-metal co-doped electrode.

Pressure-Induced Structural Phase Transition of Co-Doped SnO2 Nanocrystals

Co-doped SnO2 nanocrystals (with a particle size of 10 nm) with a tetragonal rutile-type (space group P42/mnm) structure have been investigated for their use in in situ high-pressure synchrotron angle dispersive powder X-ray diffraction up to 20.9 GPa and at an ambient temperature. An analysis of experimental results based on Rietveld refinements suggests that rutile-type Co-doped SnO2 undergoes a structural phase transition at 14.2 GPa to an orthorhombic CaCl2-type phase (space group Pnnm), with no phase coexistence during the phase transition. No further phase transition is observed until 20.9 GPa, which is the highest pressure covered by the experiments. The low-pressure and high-pressure phases are related via a group/subgroup relationship. However, a discontinuous change in the unit-cell volume is detected at the phase transition; thus, the phase transition can be classified as a first-order type. Upon decompression, the transition has been found to be reversible. The results are compared with previous high-pressure studies on doped and un-doped SnO2. The compressibility of different phases will be discussed.

Structural, optical and mechanical investigations on pure and Co-doped SnO2 thin films samples

Structural, optical and mechanical investigations on pure and Co-doped SnO2 thin films samples

Highly sensitive ethanol gas sensors based on Co-doped SnO2 nanobelts and pure SnO2 nanobelts

Highly sensitive ethanol gas sensors based on Co-doped SnO2 nanobelts and pure SnO2 nanobelts

Effect of cobalt incorporation on the photocatalytic degradation of brilliant green using SnO2 nanoparticles under visible light irradiation

• Bare and Co-doped nanocrystals of SnO 2 were synthesized by a simple chemical precipitation method. • The result of UV-DRS proposed a band gap narrowing effect on SnO 2 with cobalt doping. • The defects and vacancies induced band gap reduction and increased BET surface area on cobalt doping, have played a vital role in the photochemistry of SnO 2 . Suggested here are a simple chemical precipitation method in order to synthesize bare and various levels of Co doping samples. The harvested samples were tested for their structural, optical, morphological and photocatalytic properties. The optical study shows a decline in the band gap of SnO 2 on 0.075 M of cobalt doping. The tuned band gap of SnO 2 on doping utilizes the visible light for the photodegradation of brilliant green (BG) and recommends the usage of the optimum level of Co-doped SnO 2 in environmental remediation applications.

Synthesis of Co, Fe co-doped SnO2: characterization and applications

Thin films of iron and cobalt co-doped tin oxide were deposited by spray pyrolysis technique on heated glass at 480°C with moving nozzle method. The weight ratio of Fe/Co co-doped SnO2 (Fe CTO) changed in the range of 4-16 wt.%. The structural, optical and biological characteristics were carried out by using different characterization techniques, Results from XRD, SEM, EDX and UV-Vis analyses demonstrated successful synthesis shows polycrystalline structures with cassiterite tetragonal crystal phase with a preferential orientation for co-doped SnO2 toward (211), The average grain size of the thin films was found to be 39.29 nm, SEM images showed that all sample having uniform morphology with variant shape upon increasing dopant concentration, Transmittance spectra of all the thin films display high transparency more than 80% in the visible region, and band gap (Eg) varies from 3.49 to 3.75 eV. Antibacterial activity of the doped SnO2 thin films is studied were investigated by agar method as showed good activity against both Gramnegative Escherichia coli (E.coli) and Gram-positive bacteria Staphylococcus aureus (S.aureus).confirming these as future broad-spectrum antibacterial. Thus the preparation is a good candidate for further development into therapeutic formulations.

Enhanced UV assisted photocatalytic activity of doped and co-doped SnO2 nanostructured material

In the recent past, materials with unique properties were the versatile tools of modern technology. Metal oxide nanoparticles (NPs) are of incredible consideration because of their uncommon electrical, optical and attractive synergistic properties. One such metal oxide, tin oxide (SnO2), is widely applied and successfully researched as an n-type semiconductor in the field of electronics, as an optoelectronic sensor, as a gas sensor, as a transparent oxide in solar cells, etc. The success of these applications depends on the special qualities of SnO2 nanoparticles, which vary depending on size, manufacturing processes, dopants, etc. The present study illustrates the synthesis of pure, nickel (Ni), neodymium (Nd) doped, and Ni–Nd co-doped SnO2 NPs via low cost one step hydrothermal synthesis. X-ray diffraction study was utilized for the structural analysis and crystallite size measurement. A considerable decrease in crystallite size and band gap is obtained from the doped and co-doped samples. Scanning electron and transmission electron microscope images show an almost spherical particle with uniform size. The decolorization efficiency of methyl orange, rhodamine-6G, and eriochrome dyes was enhanced by the addition of dopants. The electrical properties of the proposed samples at various temperatures and frequencies were also reported.

Structural, optical and antibacterial activity of pure and co-doped (Fe & Ni) tin oxide nanoparticles

In this investigation, ferric (Fe) and nickel (Ni) co-doped tin oxide (SnO2) nanoparticles structural, optical, morphological, and antibacterial characteristics were synthesised, characterised, and examined. By employing SnCl2·2H2O and the transition metal precursors FeCl3 and NiCl2·6H2O with various Fe/Ni molar ratios, thermal annealing was carried out at a high temperature (700 °C). X-ray diffraction (XRD), UV–Visible spectroscopy, Photoluminescence (PL), FT-IR, and scanning electron microscopy (SEM) with energy dispersive X-ray techniques (EDX) were used to examine the materials' structural, chemical, optical, morphological, and anti-microbial capabilities. The average particle size of pure and co-doped SnO2 nanoparticles was determined to be around 52 nm and 15 nm, and SnO2 crystallites were observed to present tetragonal rutile structure with space group P42/mmm (No.136). Metal ions were replaced in the Sn lattice, as shown by Fe and Ni co-doped SnO2 nanoparticles. Pure and co-doped samples have capsule and sphere-like features in their SEM morphology. Using UV–visible diffuse reflectance spectroscopy, the optical property was examined, and it was observed that the band gaps for pure and co-doped SnO2 were 3.73 eV and 3.53 eV, respectively. The functional groups and incorporation of Fe and Ni in the prepared powder were also validated by FT-IR and EDX studies. By utilising the agar well diffusion technique and Nutrient agar, the antibacterial properties of pure, Ni-Fe co-doped SnO2 nanoparticles annealed at 700 °C were assessed. They were evaluated against various Gram-positive bacteria (Staphylococcus pheumoniae) and Gram-negative bacteria (Shigella dysenteria). The zone of incubation was found against the Gram +Ve and Gram −Ve bacterial strains.