Particle Size Of SnO2 Research Articles

Preparation of the scattering layer based on SnO2 nanocrystals for dye sensitized solar cell application

Abstract In this work, SnO2 paste was prepared based on (0.1 and 0.12 g) of SnO2 nanoparticles. The SnO2 film was deposited using Screen printing and doctor blade techniques, which it employed as scattering layer in Dye-Sensitized Solar Cell (DSSC). The crystal structure, morphology, and thermal stability of the paste were investigated using XRD, FE-SEM, and TGA techniques. The DSSC parameters were achieved to examining the effect of scattering layer on performance of DSSC. The results showed a crystalline structure predominantly composed of rutile SnO2 crystals arranged in a tetragonal pattern, with individual crystallites measuring approximately 100 nanometers in size. SEM images depicted the surface of SnO2 resembling a sponge with fine pores facilitating dye adsorption and electron mobility. Moreover, a decrease in average particle size was observed with increasing dye concentration, with the average grain size of SnO2 particles being below 100 nanometers at lower dye concentrations. TGA measurements indicated a phase transition occurring around 400 °C.

Highly responsive room-temperature NO2 sensor based on oxygen vacancies-rich SnO2-RGO hybrids

The development of graphene-based room-temperature NO2 sensors with high sensitivity remains a challenge. Herein, a wet-chemical etching strategy is investigated to introduce oxygen vacancies onto SnO2-RGO using ethanolamine (EA) as etching agent, thereby improving the NO2 response of room-temperature NO2 sensors. The oxygen vacancies-rich SnO2-RGO (EA-SnO2-RGO) is simply prepared by stirring SnO2-RGO in EA solution at room temperature, which not only decreases the size of SnO2 particles in EA-SnO2-RGO, but also introduces additional oxygen vacancies onto SnO2 particles surface. Notably, EA-SnO2-RGO sensor presents a high response value of 5.8 (1 ppm NO2) at room temperature, that is 2.1-fold larger than the response value for SnO2-RGO. Simultaneously, EA-SnO2-RGO sensor also demonstrated short response time (95 s) and good selectivity, indicating huge potential applications for room-temperature NO2 detection. This study provides new strategy to fabricate high-performance gas sensors operated at room-temperature.

A Comparative Study of Coprecipitation and Solvothermal Techniques for Synthesizing Pure and Cu‐Doped SnO2 Nanoparticles

Tin oxide (SnO2), with its low resistivity properties and high transparency in the visible spectrum, makes it an attractive electron transfer layer (ETL) for use in perovskite solar cells. Here, we use two techniques, coprecipitation and solvothermal, to synthesize pure and 4% copper‐doped SnO2. The X‐ray diffraction patterns revealed that the films synthesized using both methods have a crystalline structure with a tetragonal arrangement. Furthermore, the lack of any secondary peaks indicated the absence of mixed tin oxide (Sn2O4) or copper oxide (CuO) components. Additionally, it demonstrated that adding a 4% Cu doping concentration reduced the crystal size in both methods. The optical results indicate adequate transmission in the central range of the visible spectrum. Calculations were performed to find the energy gap of pure SnO2 in both techniques to be 3.85 eV and 4.17 eV, respectively. When we doped SnO2 with 4% Cu, this band gap energy decreased to 3.75 eV and 3.9 eV. Furthermore, with 4% Cu doping, the particle size decreases, as demonstrated by FESEM. The EDX spectroscopy images revealed that the synthesized nanoparticles consisted of copper, oxygen, and tin. The analysis of functional groups using Fourier transform infrared (FTIR) spectra and the roughness analysis using AFM images showed a decrease in roughness from 46.1 nm to 12.3 nm in doped samples prepared by solvothermal synthesis, compared to those synthesized by the coprecipitation technique from 4.7 nm to 0.3 nm. We discovered that Cu plays an essential role in reducing nanocrystalline SnO2 particle sizes. In addition, the solvothermal technique is more impressive than coprecipitation in the synthesis of tin oxide nanostructure.

Effect of SnO2 particle size on gas-sensing performance for ppb-level NO2 at room temperature under UV light

Effect of SnO2 particle size on gas-sensing performance for ppb-level NO2 at room temperature under UV light

Preparation of Nanocrystalline Nb-Doped SnO2 on Mesoporous Carbon for PEFC Electrocatalysts

Pt-based catalysts on carbon support (Pt/C) is widely used as polymer electrolyte fuel cell (PEFC) electrocatalyst. However, under high potential at the cathode, Pt detachment and aggregation due to carbon corrosion can occur. Therefore, conventional Pt/C electrocatalysts have a difficulty in durability[1]. SnO2 is known to be stable at high potentials in a PEFC cathode environment. Our research group has developed an electrocatalyst that uses carbon as a support framework, with SnO2 supported on it and Pt catalyst particles on SnO2 (Pt/SnO2/Carbon), achieving high durability [2-4]. However, the electronic conductivity of tin oxide is relativity low and the ORR activity with SnO2-based support tends to be inferior to that of Pt/C, the standard catalyst.Therefore, the objective of this study is to develop an alternative electrocatalyst that exhibits high ORR activity while maintaining high durability by using mesoporous carbon (MC) with nano-sized mesopores as a support framework and reducing the amount of SnO2 used by suppressing its grain growth.Tin oxide nanoparticles were supported on mesoporous carbon (CNovel\U0001f12c, TOYO TANSO) using ethoxide reagents. Tin oxide was doped with a small amount of niobium to improve the conductivity of SnO2 [5]. Electrocatalysts were prepared by loading of Pt particles of a few nm in diameter on the prepared supports using the Pt acetylacetonate method [6].Pt loading was examined by ICP Atomic Emission Spectroscopy. The crystallite size of SnO2 and Pt, and possible alloying of Pt and Sn were checked by XRD measurements. The electrochemical surface area (ECSA) of Pt was obtained by cyclic voltammetry (CV). The oxygen reduction reaction (ORR) activity was evaluated by determining the activation-dominant current value in the rotating disk electrode (RDE) measurement. The durability of the catalysts was evaluated by applying 60,000 of potential cycles between 1.0 and 1.5 VRHE simulating the start-up and shutdown of PEFC systems. The microstructure of electrocatalysts was observed using a field emission electron scanning microscope (SU9000, Hitachi High-Tech Corporation).Figure 1 shows (a) scanning and (b) transmission electron microscope images of the electrocatalysts before Pt loading (Sn0.98Nb0.02O2/MC). It was confirmed that tin oxide was loaded within the mesopores besides the MC surface. Furthermore, as shown in the transmission image in Fig. 1(b), the particle size of SnO2 on the surface is about 10 nm, while the particle size of SnO2 within the mesopores is about 5 nm, indicating that the presence of mesopores suppresses particle growth. Latest results of electrochemical properties of Pt-based electrocatalysts using Nb-doped SnO2 and MC after Pt catalyst decoration will be reported in this presentation. References T. Takahashi, T. Ikeda, K. Murata, O. Hotaka, S. Hasegawa, Y. Tachikawa, M. Nishihara, J. Matsuda, T. Kitahara, S. M. Lyth, A. Hayashi, and K. Sasaki, J. Electrochem. Soc., 169, 044523 (2022).Y. Nakazato, D. Kawachino, Z. Noda, J. Matsuda, S. M. Lyth, A. Hayashi, and K. Sasaki, J. Electrochem. Soc., 165 (14), F1154 (2018).S. Matsumoto, M. Nagamine, Z. Noda, J. Matsuda, S. M. Lyth, A. Hayashi, and K. Sasaki, J. Electrochem. Soc., 165 (14), F1164 (2018).T. Yoshizumi, M. Nagamine, Z. Noda, J. Matsuda, A. Hayashi, and K. Sasaki, ECS Trans., 92 (8), 479 (2019).K. Sasaki, F. Takasaki, Z. Noda, S. Hayashi, Y. Shiratori, and K. Ito, ECS Trans., 33 (1), 473 (2010).A. Hayashi, H. Notsu, K. Kimijima, J. Miyamoto, and I. Yagi, Electrochim Acta., 53, 6117 (2008). Figure 1

Boosting room-temperature ppb-level NO2 sensing over reduced graphene oxide by co-decoration of α-Fe2O3 and SnO2 nanocrystals

As promising sensing materials, reduced graphene oxide (RGO)-based nanomaterials have drawn considerable attention in the fields of gas monitoring owing to their low operating temperature. However, constructing RGO-based room-temperature gas sensors possessing ppb-level limit of detection with high sensitivity remains challenging. In this work, a series of highly sensitive NO2 sensors were fabricated using α-Fe2O3 and SnO2 co-decorated RGO hybrids (designated as α-Fe2O3/SnO2-RGO) as sensing materials. They were rationally synthesized by a one-pot hydrothermal method. Compared to SnO2 modified RGO hybrids (SnO2-RGO with bandgap of 3.88 eV), the bandgap energy of α-Fe2O3/SnO2-RGO hybrids (3.53 eV) was reduced by adding α-Fe2O3; the narrower bandgap facilitated the sensing materials to release more electrons and form more oxygen ions at room temperature. Besides, the high carrier migration of RGO, which served as continuous phase, identical structure with ultrasmall particle size of α-Fe2O3 and SnO2 (about 3–6 nm), and abundant chemisorbed oxygen species on the surface (20.8%) of the sensing materials, as well as their suitable bandgap (3.53 eV) in the sensing materials, significantly improved NO2 response at room temperature. Among the sensors fabricated, α-Fe2O3/SnO2-RGO-15-based NO2 sensor had the highest response of 7.4 with a short response time of 59 s towards 1 ppm NO2; it could even reach a response of 2.6 towards 100 ppb NO2. Notably, α-Fe2O3/SnO2-RGO-15 sample has excellent capability to recognize NO2, where the response value (7.4) towards 1 ppm NO2 is about 7 times higher than that of 100 ppm ammonia and common volatile organic compounds (formaldehyde, toluene, ethanol and acetone). Such NO2 sensor has superior repeatability with negligible response deviation towards 1 ppm NO2 for four reversible cycles. This makes it to have a great potential application in the field of NO2 detection.

Effect of CuO and SnO2 particle size on hot extrusion deformation of AgCuOSnO2: Finite element simulation and experimental study

Effect of CuO and SnO2 particle size on hot extrusion deformation of AgCuOSnO2: Finite element simulation and experimental study

Sulfamic: acid incorporated tin oxide: Acidity and activity relationship

Herein we study the activity and acidity relationship, Sulfamic acid (SA) has been incorporated with tin oxide (Sn). Acidity measurement confirmed the presence of dual-acidic sites. SA hinders the crystallization and inhibits SnO2 crystal growth. The particle size of SnO2 (2.1–8.2 nm) and the SBET values of samples were found to be dependent on the SA content and calcination temperatures. The increase in the surface acidity was found to occur with increasing the thermal treatment up to 450 °C, while further increasing of calcination temperature is accompanied by a decrease in the surface acidity. Lewis and Bronsted acid sites play important role in the catalytic activity, The SA-Sn nanoparticles are efficient for the synthesis of 14-aryl-14H-dibenzo[a,j] xanthene under solvent-free conditions in good to excellent yields and the sample contains 25 wt% SA has the highest activity than the others under the same reaction conditions.

Fluorine-doped tin oxide as efficient solid acid catalyst: acidity and the catalytic activity relationship

Herein we report an easy and facile method for preparation of Tin oxide-doped fluorine. SnO2 nanoparticles were synthesized using the sol–gel method. The obtained Sn(OH)4 is calcined at 450 °C then impregnated with different loading 10–55 wt.% of HF as a source of fluoride, followed by calcination at 200, 300, and 400 °C. The particle size of SnO2 was found to be between 5 and 8 nm. The SBET values and pore size distribution of the F–Sn data were discussed. Examining the surface acidity, confirm that the addition of fluoride ions increases both of the total surface acidity and the ratio of Bronsted to Lewis acid sites. The catalytic activity of the fluoride-tin oxide nanoparticles solid catalysts was investigated through the synthesis of 3,4-dihydropyrimidin-2(1H)-one. 45 F–Sn catalyst calcined at 200 °C has the highest and strongest acid sites (Ea = 450.0 mV) that enhance the catalytic activity reaching the maximum yield of (96.5%). The F–Sn catalysts were reused several times with no activity loss.

Pulsed Laser Ablation of Tin Oxide Nanoparticles in Liquid for Optoelectronic Devices

Laser ablation of tin oxide (SnO2) nanoparticles (NPs) was carried out by irradiation of tin target in methanol and aqueous NaCl solutions with nanosecond laser pulses. X-ray diffraction (XRD) studies show that the synthesized nanoparticles are polycrystalline tin oxide with tetragonal phase. Scanning electron microscope (SEM) and transmission electron microscope (TEM) were used for characterization of the shape, particle size and particle distribution of tin oxide nanoparticles. SEM results reveal that the synthesized NPs have spherical shape and the presence of agglomerated NPs was observed. TEM investigation confirms that the average particle size of SnO2 synthesized in methanol was 40 nm and in NaCl solution was around 25 nm. The optical energy gap of SnO2 NPs prepared in methanol and NaCl solutions were 3.8 eV and 3.95 eV, respectively. Energy dispersive X-ray (EDX) confirms the formation of SnO2 NPs. The parameters of n-SnO2NPs/p-Si heterojunction photodetectors, namely, dark and illuminated current-voltage characteristics, photovoltaic properties, spectral responsivity and specific detectivity were measured. The responsivity of the photodetector prepared in NaCl solution was 0.53A/W at 410 nm, while the responsivity of photodetector prepared in methanol was 0.43A/W at 410 nm.

Oxygen vacancy and size controlling endow tin dioxide with remarked electrocatalytic performances towards vanadium redox reactions

Nanomaterials have been applied in electrochemistry fields due to advantages of large surface area and high surface activity. Nano mental oxides have been widely used as catalyst in vanadium redox flow battery. In this work, oxygen vacancy and size controlling strategies were used to endow SnO2 with remarked electrocatalytic performances towards vanadium redox reactions, which were realized by facile Cr doping. A series of Sn1-xCrxO2-δ (x = 0.01, 0.02 and 0.04) samples were prepared by using sol-gel method and high-temperature calcination. Cr doping reduces the particle size of SnO2 and increases oxygen vacancies in crystal structure of SnO2. Cr-doped SnO2 displays the improved electrochemical performance for vanadium redox reaction compared with SnO2. It owes to Cr-doped SnO2 with more active sites and larger reaction place than SnO2. SnO2/Cr-2 (Sn0.98Cr0.02O2-δ) exhibits the best electrocatalytic activity for V3+/V2+ redox reaction as well as better electrocatalytic activity for VO2+/VO2+ redox reaction than SnO2. The graphite felt was loaded by SnO2/Cr-2 as bifunctional electrodes in cell. The cell shows the improved electrolyte usage and better electrochemical stability in cycling test compared with pristine cell. SnO2/Cr-2 reduces electrochemical polarization and increases energy and voltage efficiency of the cell. Overall, Cr doped SnO2 is an attractive catalyst for improving electrochemical performance of vanadium redox reaction.

Complex dielectric behavior of doped polyaniline conducting polymer at microwave frequencies using time domain reflectometry

Nano size Tin Oxide is prepared in the laboratory from SnCl4 and ammonia solution. The polyaniline (PAni) conducting polymer is synthesized by chemical oxidation method using ammonium persulphate as oxidizing agent. The PAni-SnO2 composite was prepared by insitu method. Scanning electron microscopy (SEM) results confirm the particle size of SnO2 in the range of 30-48 nm. Dielectric behavior of nanocomposite of PAni-SnO2 was studied in the frequency range 0.01- 20 GHz at -5,0,5,10,15,20 and 25oC. The dielectric constant (real part ε׳) and dielectric loss (imaginary part ε״) have been evaluated. The relaxation time (τ, τo, and τ1) are calculated. The relaxation time was found to be of the order of ps. The dielectric properties of the solids in the form of powders may be useful in understanding the structural behavior of particles in an alternating field. These studies may also be used to formulate models for predicting the dielectric properties. The microwave absorbing property is decided from the dielectric loss of the material. It is observed that the PAni-SnO2 composite can be a good electromagnetic shielding material.

Synergistically effective and highly visible light responsive SnO2-g-C3N4 nanostructures for improved photocatalytic and photoelectrochemical performance

This paper reports the facile and scalable fabrication of mesoporous and high surface area tin oxide and tin oxide-graphitic carbon nitride nanostructures {SnO2, SnO2-C3N4 (2 mM) and SnO2-g-C3N4 (4 mM)} using a template-free hydrothermal approach. The overall characterisation revealed a high surface area (~181 m2g−1) with a mesoporous nature, relatively small particle size of SnO2 (~2–3 nm) grown successfully on g-C3N4 sheets, and significantly improved optical behaviour for visible light utilisation. Comparative screening of different SnO2-based nanostructures revealed significant improvements in visible-light induced photocatalytic degradation and photoelectrochemical performance. The visible light-induced degradation of model pollutants, such as Methylene blue (MB) and Congo red (CR), was achieved using SnO2-g-C3N4 (4 mM) with total efficiencies of ~99.38% and ~96%, respectively. The optimal SnO2-g-C3N4 (4 mM) as a photocatalyst showed first order rate constants for MB and CR degradation of 6.39 × 10−2 min−1 and 2.9 × 10−2 min−1, respectively. Moreover, the investigation of different modified photoelectrodes of SnO2-g-C3N4 (4 mM) and SnO2-g-C3N4 (2 mM) show more than eight and five times higher photoelectrochemical performance than that of SnO2, respectively. The possible synergistic effect makes the SnO2-g-C3N4 (4 mM) nanostructure an exceptional photocatalytic and photoresponsive material under visible light that can be used for future environmental and energy-related purposes.

Leaching-resistant SnO2/γ-Al2O3 nanocatalyst for stable electrochemical CO2 reduction into formate

Tin(IV) oxide (SnO2) is the catalyst most commonly used for electrochemical reduction of CO2 into formate. However, the electrocatalytic performance of SnO2 is not ensured due to its poor long-term stability. Here, we report our study on the electrochemical stability of SnO2 for 152h and describe an approach to achieve stable SnO2 electrodes using a γ-alumina (γ-Al2O3) support. The γ-Al2O3 reduces the leaching of Sn from the supported-SnO2 during CO2 electrolysis due to the strong interaction of the support with the electrocatalyst. This maintains the particle size, morphology, and crystallinity of SnO2. Thereby, pulverization of SnO2 is prevented and stable selectivity towards CO2 reduction results. The prepared SnO2/γ-Al2O3 exhibits much more stable Faradaic efficiency (65.0% at 152h) and partial current density (21.7mAcm−2 at 152h) for formate synthesis than does unsupported SnO2 electrocatalyst (14.2% Faradaic efficiency; 4.6mAcm−2 of partial current density at 152h).

XPS and Kelvin probe studies of SnO2/RGO nanohybrids based NO2 sensors

The present paper reports the successful detection of NO2 using the hydrothermally synthesized SnO2/RGO nanohybrids. The nanohybrids successfully detected NO2 below its threshold limit value (TLV) with a minimum detection limit of 0.5 ppm. The 3-fold sensor response (Rg/Ra) was obtained towards 3 ppm of NO2 at an operating temperature of 200 °C. Importantly, the nanohybrids exhibited faster response kinetics. For example, the response and the recovery times of 10 and 40 s, respectively were obtained for 1 ppm NO2 exposure. In nanohybrids, the particle size of SnO2 is ~5–7 nm which is comparable to twice of its Debye length (3 nm) and accordingly, benefits the charge transport and the sensor response. NO2 adsorption on the sensor surface is further studied using the Elovich model. The obtained results were further corroborated with the observations from X-ray photoelectron spectroscopy (XPS) and Kelvin probe studies performed before and after exposure to NO2. The considerable long-term stability and selectivity indicate that the developed sensor can find a promising application in NO2 detection.

SnO­2 Tailored by CuO for Improved CH4 Sensing at Low Temperature

Trace level methane (CH4) detection is demonstrated at low temperature. Functional metal oxide of SnO2 tailored by CuO is prepared via a co‐precipitation chemical route followed by annealing in air. Raman spectroscopy confirms presence of Ag mode of CuO at 290 cm−1 along with A1g mode of SnO2 at 630 cm−1. Results from the X‐ray diffraction and transmission electron microscope indicate that both crystalline SnO2 and CuO are present in the composite. Particle size of SnO2 is found to be larger in the composite than the pristine‐annealed SnO2 of 25 nm at 800 °C. However, sensor studies with CH4 reveal stronger response and low operational temperature of 100 °C for the composite in comparison to the pristine‐annealed SnO2 which shows poor response (<1%) even at higher temperature of 150 °C. Current–voltage measurements support the formation of local p–n junctions in the CuO–SnO2 composite. The role of n–p junction in the composite is elaborated and correlated to the improved response.

Reinforced photocatalytic reduction of SnO2 nanoparticle by La incorporation for efficient photodegradation under visible light irradiation

In this era of technology, evolving and understanding the physicochemical properties of a novel photocatalytic material to degrade organic species in polluted water is most needed all over the globe due to environmental production. This study reports the influence of lanthanum (La) in physicochemical properties of tin (II) dioxide (SnO2) nanoparticles and its application towards methylene blue (MB) degradation under sunlight. The SnO2, 2 mol% La incorporated SnO2 and 4 mol% La incorporated SnO2 (4 mol% La) nanoparticles were synthesized by simple co-precipitation method and characterized. X-ray diffraction patterns indicate higher angle shifts and peak broadening with respect to increase in La concentration. High-resolution transmission electron microscopic images (HR-TEM) reveal that SnO2 particle size decreases with respect to increase in La concentration. Morphological analysis shows that addition of La changes SnO2 morphology from agglomeration to segregated porous nature. Energy dispersive spectrum confirms the presence of parent and dopant elements in La incorporated SnO2 nanoparticles. UV–Visible spectrum indicates the increase in the band gap of La incorporated SnO2 due to the quantum size effect. The surface disorder, reduction in particle size and phonon confinement are identified from the Raman spectral analysis. Moreover, electrochemical analysis demonstrates the possible electrochemical activity of the materials as well as confirms that La provides higher charge transfer kinetics and stability to SnO2 nanoparticle. In addition, the calculated CBM potential confirms that La increases the redox potential of SnO2 nanoparticle, which is an ample condition to reduce O2 as ·O2−. The fast MB degradation kinetics achieved by 4 mol% La-SnO2 nanoparticle, which degrades 99% of MB within 60 min under sunlight irradiation and exhibits more than 90% photodegradation efficiency up to ten recycle. A through study of possible photocatalytic mechanism for the photocatalytic degradation is discussed.

Bi-functional nitrogen-doped carbon protective layer on three-dimensional RGO/SnO2 composites with enhanced electron transport and structural stability for high-performance lithium-ion batteries

Three-dimensional reduced graphene oxide@SnO2@nitrogen-doped carbon (3DG@SnO2@N-C) composites are designed as high efficiency anode materials for lithium-ion batteries. The SnO2 particle size, surface area and pore size distribution of the 3DG@SnO2@N-C could be simply controlled by altering the GO dosages. The optimized 3DG@SnO2@N-C electrode demonstrates a reversible capacity of 1349.5 mAh g−1 after 100 cycles at the current density of 100 mA g−1. Based on the structural and electrochemical dynamic tests, the bi-functional N-doped carbon coating layer could serve as both conductive channel for electron transport and as buffer layer to alleviate the volume change of embedded SnO2 NPs. In addition, the cross-linked conducting 3DG with porous structure attributes to the reduced electron transport and Li ion diffusion resistances, which finally leads to the enhanced cycling stability and rate performances.

Sn-SnO2 hybrid nanoclusters embedded in carbon nanotubes with enhanced electrochemical performance for advanced lithium ion batteries

Sn-based materials are one promising high-capacity anode material for lithium-ion batteries. The practical application of Sn-based materials is generally restricted by their significant capacity fading due to the volume expansion and structural changes during Sn alloying/dealloying process. In this work, Sn-SnO2 hybrid nanoclusters are embedded into carbon nanotube network, forming a Sn-SnO2@CNT composite. The Sn-SnO2 nanoclusters are consisted of interconnected Sn and SnO2 nanocrystals, in which SnO2 forms a beneficial environment for the alloying/dealloying of Sn. The ultrafine particle size of SnO2 (<10 nm) also allows a highly reversible conversion reaction, contributing to high overall capacities. The Sn-SnO2 nanoclusters are uniformly dispersed in CNT matrix, therefore providing abundant active sites for Li-ion storage. The CNT matrix functions in improving electrical conductivity, preventing Sn aggregation, and accommodating Sn volume change in prolonged cycles. As a result, the hybrid Sn-SnO2@CNT electrode shows excellent rate capability (1059 mAh g−1 at 1 A g−1 and 960 mAh g−1 at 5 A g−1, corresponding to 0.53 mAh cm−2 at 0.5 mA cm−2 and 0.48 mAh cm−2 at 2.5 mA cm−2) and outstanding cycling stability (86% capacity retention after 1000 cycles at 0.5 A g−1), making it an promising anode material for high-performance lithium-ion batteries.

Ionic-liquid-bifunctional wrapping of ultrafine SnO2 nanocrystals into N-doped graphene networks: high pseudocapacitive sodium storage and high-performance sodium-ion full cells.

Sodium ion batteries are in great need of electrode materials with high specificity and rate capability being developed. The sluggish reaction kinetics of SnO2-based materials has impeded their applications as anodes of SIBs. Designing electrode materials with high pseudocapacitive contribution can increase the near-surface faradaic reaction, which helps to improve their kinetics and achieve high rate capability. Here, we designed a high-pseudocapacitance sodium storage anode SnO2/N-rGO by downsizing the particle size of SnO2 and constructing an N-doped graphene wrapped structure. The ultrafine structure of SnO2 ensures the high faradaic near-surface reaction, while the N-doped graphene matrix guarantees the superior electron and Na+ diffusion. Meanwhile, the wrapped N-doped graphene acts as a buffer layer to alleviate the volumetric changes of the active SnO2. The obtained ultrafine SnO2/N-graphene composite exhibits a high capacity of 607.6 mA h g-1 at 50 mA g-1 with an impressive rate capability (261.8 mA h g-1 at 2 A g-1) in Na+ half-cells. Furthermore, a good performance with a capacity of 133.3 mA h g-1 at 2.4 A g-1 in Na+ full-cells can also be achieved, which makes it a promising anode material for SIBs.