查找使用阿拉丁产品的科研文献

(001)-Exposed mesoporous SnO2 nanosheets for room temperature trace chlorine monitoring

Meng Weiqi,Zheng Ming,Zhang Xianfa,Guo Chuanyu,Xu Yingming,Huang Chaobo,Cao Zongshuang,Dong Xin,Huo Lihua,Cheng Xiaoli

SnO 2 mesoporous nanosheets with dominant the (001) crystal planes were synthesized via a mesoporous template-confined strategy. The cetyltrimethylammonium chloride used was both the mesoporous template and structure-directing agent, which enables the SnO 2 nanosheets to have a rich mesoporous structure and effectively promote the rapid diffusion of gaseous chlorine (Cl 2 ). Meanwhile, the abundant Sn unsaturated coordination sites on the (001) planes significantly enhance Cl 2 adsorption. The SnO 2 -(001) sensor achieved highly sensitive detection of Cl 2 at room temperature. It exhibited a high response of 408 toward 5 ppm Cl 2 , low practical detection limit (10 ppb), excellent selectivity and long-term stability. This breakthrough not only overcomes the high-temperature working limitation of traditional SnO 2 -based Cl 2 sensors. In addition, the sensor was employed to monitor Cl 2 emissions during the use of chlorine-containing disinfectants. Test results indicated that the Cl 2 concentration surpassed the safety threshold within 7-14 min of disinfectant application. It demonstrated its strong potential for practical applications. Furthermore, it lays the solid foundation for optimizing other metal oxide-based room temperature gas sensors. Graphical

Crystal structure and microwave dielectric properties in CoO-SnO2-Nb2O5 system

Yun Zhang,Shihua Ding,Tianxiu Song,Yingchun Zhang

CoSnNb 2 O 8 ceramic with medium-permittivity was initially generated. Compositionally induced phase formation was identified by X-ray diffraction. Tetragonal rutile-type CoSnNb 2 O 8 was obtained from the reaction of SnO 2 with intermediate phase CoNb 2 O 6 . Both the dielectric constant ε r and quality factor Q  ×  f initially increased with the sintering temperature, reaching the maxima at around 1225 °C, and declined thereafter. They were discussed based on the ionic polarizabilities and packing fraction, respectively. The temperature coefficient of resonant frequency τ f primarily depended on the Nb-site bond valence, as well as oxygen octahedra distortion. When sintered at 1225 °C, the CoSnNb 2 O 8 ceramic exhibited optimum properties with ε r  = 31.8, Q  ×  f  = 43,000 GHz, and τ f  = 35.01 ppm/°C.

In situ formation and doping of Ag/SnO2 electrical contact materials

Guijing Li,Xueqian Fang,Wenjie Feng,Jinxi Liu

The Ag/SnO 2 electrical contact materials with different doping concentration of Zr and Fe were successfully fabricated through self-assembly precipitation and powder metallurgy method. The microstructures of Ag-SnO 2 composite powders and the prepared Ag/SnO 2 contact materials were investigated by a Scanning Electron Microscopy (SEM) coupled with EDS and EBSD systems. The results showed that the SnO 2 nanoparticles with typical geometric shapes were formed and distributed in Ag matrix. The electrical conductivity of the Ag/SnO 2 materials was significantly increased by 16 percent with the doping of 3 wt% ZrO 2 in SnO 2 . The surface morphology of the Ag/SnO 2 materials after arc erosion was further characterized. The formation of the Sn(Zr)O 2 and Sn(Fe)O 2 solid solution in Ag/SnO 2 significantly improved the arc dispersion and arc erosion resistance. This work can offer a novel approach to design Ag/SnO 2 contact materials for good electrical performances.

Oxygen-controlled structures and properties of transparent conductive SnO2:F films

Fayu Wu,Xinru Tong,Zhuo Zhao,Jianbo Gao,Yanwen Zhou,Peter Kelly

The morphology and properties of the transparent SnO 2 :F (FTO) films, deposited by RF magnetron sputtering at varying oxygen flows from 0∼3sccm, were examined. For FTO films deposited with 0∼1sccm O 2 , the polar unsaturated (101) planes were the preferred orientation, resulting in resistivity values as low as 10 −3  Ω cm, and the transparency of 86.5% in the visible range. The saturated (110) orientation planes associated with {101} facets formed knee twin crystallites for the FTO film prepared at 2sccm O 2 . Further increases of O 2 led to severe mis-orientation of the crystals. The average transparency in the visible range increased up to 95%, but these FTO films were hardly conductive due to the oversupply of O 2 . The optical band gaps became wide at first and then narrow again as the increases of the oxygen flow rates.

A high performance SnO2/C nanocomposite cathode for aluminum-ion batteries

Hongyan Lu,Yuanxin Wan,Tianyi Wang,Rong Jin,Peitao Ding,Rong Wang,Yong Wang,Chao Teng,Linling Li,Xiaoliang Wang,Dongshan Zhou,Gi Xue

Rechargeable aluminum-ion batteries have been researched extensively due to their attractive features, such as the abundant aluminum resources and high capacity resulting from the three-electron redox properties. Herein, a porous carbon supported SnO2 nanocomposite is reported as a cathode material for AIBs. The resultant cell exhibits a high discharge specific capacity of 370 mA h g−1 (with an initial value of 434 mA h g−1) at 50 mA g−1. In the cycling performance, the cell retains a stabilized discharge capacity of 72 mA h g−1 after 20 000 cycles with a coulombic efficiency of ∼100% under an ultrahigh current density of 2 A g−1. Owing to the well-defined nanostructure, side reactions and pulverization of active particles can be prevented. The results indicate that the SnO2/C nanocomposite is a favorable cathode material for AIBs and opens up a new opportunity for the design of high-performance AIBs.

Electrochemical degradation of chloramphenicol using Ti-based SnO2–Sb–Ni electrode

Li Dan,Zhang Libao,Gao Weichun,Meng Jing,Guan Yinyan,Liang Jiyan,Shen Xinjun

Antibiotic residues may be very harmful in aquatic environments, because of limited treatment efficiency of traditional treatment methods. An electrochemical system with a Ti-based SnO 2 –Sb–Ni anode was developed to degrade a typical antibiotic chloramphenicol (CAP) in water. The electrode was prepared using a sol–gel method. The performance of electrode materials, impact factors and dynamic characteristics were evaluated. The Ti-based SnO 2 –Sb–Ni electrode was compact and uniform as shown by characterization using SEM and XRD. The electrocatalytic oxidation of CAP was carried out in a single-chamber reactor by using a Ti-based SnO 2 –Sb–Ni electrode. For 100 mg L −1 CAP, the CAP removal ratio of 100% and the TOC removal ratio of 60% were obtained at the current density of 20 mA cm −2 and in a neutral electrolyte at 300 min. Kinetic investigation has shown that the electro-oxidation of CAP on a Ti-based SnO 2 –Sb–Ni electrode displayed a pseudo-first-order kinetic model. Free radical quenching experiments presented that the oxidation of CAP on Ti-based SnO 2 –Sb–Ni electrode resulted from the synergistic effect of direct oxidation and indirect oxidation (·OH and ·SO 4 − ). Doping Ni on the Ti/SnO 2 –Sb electrode for CAP degradation was presented in this paper, showing its great application potential in the area of antibiotic and halogenated organic pollutant degradation. Ti/SnO 2 –Sb–Ni anodes were first applied to remove CAP by electrocatalytic oxidation. The removal ratios of CAP and TOC by anodic oxidation and cathodic reduction were first compared. The degradation of CAP on the Ti/SnO 2 –Sb–Ni electrode results from the synergistic effect of direct oxidation and indirect oxidation (·OH and ·SO 4 − ). ·SO 4 − and direct oxidation contributed much to the degradation of CAP.

Chestnut-like SnO2/C nanocomposites with enhanced lithium ion storage properties

Lie Yang,Tao Dai,Yuecun Wang,Degang Xie,R. Lakshmi Narayan,Ju Li,Xiaohui Ning

Chestnut-like SnO 2 and SnO 2 /C nanocomposites with hierarchical structures are synthesized by hydrothermally oxidizing Sn nanoparticles in glucose solution. Structural characterizations using SEM and TEM reveal that the SnO 2 nanoparticles are composed of numerous, randomly arranged SnO 2 nanosheets with hollow cores. Owing to the short electron and ion diffusion distances and transformation strain accommodation mechanism of this structure the new SnO 2 /C nanocomposites exhibit enhanced lithium ion storage properties with a capacity of ~930   mAh   g −1 and capacity retention of about 96% after 100 cycles at 0.1   C. An in situ TEM study of the electrochemically driven lithiation/delithiation of SnO 2 /C nanocomposites reveals that their enhanced cycling stability is mainly facilitated by the limited volume expansion and excellent mechanical robustness of the hollow chestnuts.

Electrospun Pt-doped SnO2 nanofibers enabling sensitive and selective NO2 detection

Guojun Sun,Jiang Liu,Guiwu Liu,Yuli Zhao,Xiangzhao Zhang,Mingyuan Wang,Guanjun Qiao

Pristine SnO 2 is extensively employed in gas sensing applications owing to its excellent stability in acidic and alkaline environments; however, its sensitivity and selectivity still require improvement. This study reports the fabrication of Pt-doped SnO 2 (Pt-SnO 2 ) nanofibers via electrospinning and subsequent calcination, along with the optimization of Pt doping concentration for efficient NO 2 detection. The optimized sensor (0.5 Pt-SnO 2 ) displays significantly enhanced sensing performance relative to pristine SnO 2 , which is primarily ascribed to the elevated oxygen vacancy density and enlarged specific surface area. This sensor exhibits an approximately 20-fold increase in response to 100 ppm NO 2 compared with pristine SnO 2 and achieves a minimum detectable concentration of 5 ppb. The 0.5 Pt-SnO 2 sensor also demonstrates satisfactory response and recovery behavior over a wide detection span, along with remarkably high selectivity, excellent repeatability, and good long-term stability. Furthermore, first-principles calculations confirm that Pt-doped SnO 2 possesses higher adsorption energy and much greater charge transfer than pristine SnO 2 . This work presents a facile and robust strategy to enhance the NO 2 sensing performance of SnO 2 , with potential applications in industry and modern agriculture.

Promotion on Formaldehyde Sensing of 3D Porous SnO2 by Eu Doping

Chunxia Tian,Haiying Li,Xi-Ang Tian,Li Liu

Preparation of anatase/rutile TiO2/SnO2 hollow heterostructures for gas sensor

Changchao Jia,Tao Dong,Meng Li,Peng Wang,Ping Yang

TiO 2 hollow hierarchical architectures with anatase and rutile phases are fabricated. The hierarchical structure uniformly decorated with SnO 2 nanoparticles endows a fascinating sensing performance for detecting triethylamine (TEA). Hierarchical structure provides a close connection between anatase/rutile TiO 2 and SnO 2 , which is in favor of efficient electrons transfer . It is found that TiO 2 @SnO 2 as a novel sensing material has high response at low level of TEA and rapid responding speed in comparison with individual TiO 2 components. In the case of 5 ppm TEA gas under the operation temperature of 240 °C, the response value of TiO 2 @SnO 2 sample is up to 21.6, which is three times higher than that of TiO 2 sample. The responding speed of TiO 2 @SnO 2 sensors elevates 28% in comparison with TiO 2 . This result is utilizable for developing the high efficiency gas sensors using hollow hierarchical architecture.

SnO2 as a high-efficiency polysulfide trap in lithium–sulfur batteries

Jing Liu,Lixia Yuan,Kai Yuan,Zhen Li,Zhangxiang Hao,Jingwei Xiang,Yunhui Huang

The ithium–sulfur battery stands as one of the most promising successors of traditional lithium-ion batteries due to its super high theoretical energy density, but practical application still suffers from the shuttle effect arising from soluble intermediate polysulfides. Here, we report SnO2 as a chemical adsorbent for polysulfides. As an interlayer between the cathode and separator, SnO2 gives better results to prevent the polysulfides from diffusing to the lithium anode than as a modifier of the carbon matrix directly. The lithium–sulfur battery with an SnO2 interlayer delivers an initial reversible capacity of 996 mA h g−1 and retains 832 mA h g−1 at the 100th discharge at 0.5 C, with a fading rate of only 0.19% per cycle. The improvements benefit from the quasi-open space provided by the interlayer configuration for the diffused sulfur species, which can largely relieve the loss of active substances caused by the volume effect during the lithiation/delithiation process.

Mussel directed synthesis of SnO2/graphene oxide composite for energy storage

Wenhao Chi,Zhaoyong Zou,Wenxuan Wang,Fuqiang Wan,Hang Ping,Jingjing Xie,Weimin Wang,Zhengyi Fu

A living organism is a complex “biosynthesis factory” for the fabrication of materials under environmentally benign conditions, which is worth studying to extend synthesis techniques. Inspired by the formation process of pearls, living mussels have been used to direct the formation of nitrogen-doped anatase TiO2. Here, instead of only synthesizing single-phase materials, we extend the technique for the fabrication of a SnO2/graphene oxide composite. The tin chloride hydroxide hydrate precursor transforms into SnO2 nanocrystals in situ on the surface of graphene oxide with good dispersion and high load to form a homogeneous microstructure under the direction of mussels at ambient temperature. The SnO2/graphene oxide composite exhibits improved lithium storage performance as the anode of a lithium-ion battery. A stable reversible capacity can be achieved, which is up to 1099 mA h g−1 after 100 cycles at a current density of 100 mA g−1. This study demonstrates the possibility and practicability of synthesizing anthropogenically useful composite materials in living organisms, which is advantageous to extend synthesis methods and reduce energy consumption.