ZnSnO3的微波合成与表征

以锡酸钠和廉价的硫酸锌为原料,利用快速节能的微波技术合成了ZnSnO3微米球和纳米立方块。用SEM和XRD对产物进行了表征,XRD结果表明,在微波条件下只需30min即可获得结晶度较好的锡酸锌,SEM结果显示,锡酸锌微米球的直径在0.5μm-1.5μm之间,锡酸锌纳米立方块的平均尺寸在150nm左右。     

偏锡酸锌纳米材料的制备及其HCHO气敏性研究

采用水热法在不同条件下制得3种不同形貌的纳米偏锡酸锌(ZnSnO3)。通过XRD、SEM等分别对偏锡酸锌的晶体结构、微观形貌等进行表征,结果表明:160℃、15h水热条件下制得了全立方形纳米偏锡酸锌;180℃、15h水热条件下制得的纳米偏锡酸锌为立方-松枝混合形貌;而180℃、24h水热条件下得到偏锡酸锌全为片状,片厚约15nm。采用传统旁热式结构对上述3种纳米偏锡酸锌进行HCHO的敏感性能研究,结果发现3种形貌的偏锡酸锌对甲醛都表现出良好的气敏特性,其中片状偏锡酸锌的甲醛气敏特性最优异,工作温度300℃时对1×10-6甲醛有较好的响应。     

ZnO/ZnSnO3纳米复合物的制备及其HCHO气敏性研究

采用水热法在不同温度下制得两种氧化锌/偏锡酸锌(ZnO/ZnSnO3)复合氧化物。通过XRD、SEM、比表面积及孔隙度分析仪分别对复合氧化物的晶体结构、微观形貌、比表面积等进行表征,结果表明,160℃水热条件制得了氧化锌/片状偏锡酸锌纳米复合氧化物,而180℃条件下制得了颗粒状ZnO/ZnSnO3纳米复合物,平均粒径16nm。采用传统旁热式结构对上述两复合氧化物进行HCHO敏感性能研究,结果发现两种复合氧化物对甲醛都表现出良好的气敏特性,其中氧化锌/片状偏锡酸锌复合氧化物的甲醛气敏特性尤为突出,工作温度110℃时对0.5×10-6甲醛有很好的响应。     

Facile fabrication and enhanced gas sensing properties of ZnSnO3/NiO heterostructures

Journal of Materials Science: Materials in Electronics - The sensing performance of gas sensitive materials can be improved by adjusting their microstructure and electronic structure. In this work,...     

掺杂ZnSnO3气敏特性及实用性研究

本文通过对ZnSnO3传感器进行各种掺杂来提高其灵敏度、选择性和工作温度.结果发现:在所有的掺杂剂中,TiO2能显著提高其灵敏度而且灵敏度是无掺杂ZnSnO3传感器的两倍多,并且最佳的掺杂量为5%mol.此外,这种掺杂ZnSnO3传感器的回复-响应时间为10S左右,足够实际应用.在有其它气体存在的情况下,这种掺杂ZnSnO3传感器仍然对乙醇具有较高的选择性.用SEM对其进行了解释.因此,掺TiO2的ZnSnO3传感器对乙醇具有较高的灵敏度并且保持较高的选择性,能够重复使用以及60h后,其灵敏度可保持稳定值.     

贵金属Pd离子掺杂纳米ZnSnO3的氢敏性能及掺杂机理

为了提高ZnSnO3的氢敏性能,以共沉淀法制备ZnSnO3并对其进行了贵金属Pd2＋掺杂.采用X射线衍射仪（X-ray diffraction,XRD）及透射电镜（transmission electron microscopy,TEM）对制备的气敏材料进行结构及形貌表征,并使用静态配气法测试了掺杂前后ZnSnO3的氢敏性能.结果表明：掺杂Pd2＋可显著提高ZnSnO3的氢敏性能.在工作温度为240℃、浓度为300×10-6的条件下,Pd2＋掺杂纳米ZnSnO3对氢气的灵敏度为12,是未掺杂时的3倍.基于第一性原理探讨气敏机理,计算结果表明：Pd2＋掺杂改变了ZnSnO3能带间的电子运动状态,使ZnSnO3费米能级由0.725 eV移动到1.035 eV,在费米能级附近产生新的电子峰,使其电导性能在气敏反应过程中改变更为明显.Pd2＋掺杂还使ZnSnO3表面吸附氧的能力显著增加,对提高氢敏性能起到了关键作用.     

Diffusion-activated high performance ZnSnO/Yb2O3 thin film transistors and application in low-voltage-operated logic circuits

The flourishing metal-oxide high-k dielectric materials have been regarded as the vital components of low voltage operated flexible transparent electronic devices.We herein report that ytterbium oxide(Yb2O3)and ZnSnO(ZTO)thin films were firstly integrated into ZTO-based thin film transistors(TFTs)with superior performance.Results have indicated that the 500℃-annealed ZTO/Yb2O3 TFTs possess the large saturation mobility of 9.1 cm2 V-1 S-1 and the high on/off current ratio of 2.15×107,which even surpass those of reported In-based TFTs.The deteriorative electrical properties in the aging process can be attributed to the carrier capture mechanism.However,the 460℃-processed TFTs demonstrate a tenfold increase in saturated mobility and an increase in on/off current ratio after 10 days aging.The inspiring electrical properties are attributed to the diffusion-activated carrier enhancement mechanism and electrons donor role of water molecular,which introduces a facile method to boost the device per-formance at lower processing temperatures.The neglected threshold voltage variations of 0.06 V and-0.2 V have been detected after bias stability experiments.The superior bias stability can be attributed to the charge delay effect induced by the continuous electric field.Meanwhile,the ultrahigh on/off cur-rent ratio of 1.1 x 107 and the recoverable transferring performance have verified the aging-activated mechanism.To confirm its potential application in digital circuits,a resistor-loaded inverter with gain of 5.6 has been constructed and good dynamic response behavior have been detected at a low voltage of 2 V.As a result,it can be concluded that the high temperature annealing TFTs need immediate encapsula-tion,while the performance of the lower temperature processing samples can be optimized after aging treatment,indicating the potential prospect in low power consumption large-scale flexible transparent devices.     

单层和双层包覆ZnSnO_3微胶囊对PVC膜阻燃及抑烟性能影响

采用极限氧指数(LOI)值、垂直水平燃烧测试、烟密度测试(SDR)、SEM、TG分析,研究了单层ZnSnO_3@Mg(OH)_2微胶囊和双层ZnSnO_3@Mg(OH)_2@三聚氰胺甲醛树脂(MF)微胶囊对聚氯乙烯(PVC)膜的阻燃及抑烟性能的影响。结果表明,ZnSnO_3@Mg(OH)_2和ZnSnO_3@Mg(OH)_2@MF微胶囊能有效提高PVC膜阻燃、抑烟、抗熔滴、自熄性能;且随着单层或双层微胶囊含量的增加,ZnSnO_3@Mg(OH)_2/PVC和ZnSnO_3@Mg(OH)_2@MF/PVC膜的极限氧指数增加,但其烟密度和自熄时间降低。TG结果表明,随着微胶囊含量增加,ZnSnO_3@Mg(OH)_2/PVC和ZnSnO_3@Mg(OH)_2@MF/PVC膜的初始降解温度向低温偏移,且其残炭量增加。ZnSnO_3@Mg(OH)_2/PVC和ZnSnO_3@Mg(OH)_2@MF/PVC膜的残炭SEM表明,添加ZnSnO_3@Mg(OH)_2和ZnSnO_3@Mg(OH)_2@MF微胶囊能有效地促进材料燃烧时产生致密碳层,不仅可以抑制氧气和热量进入PVC膜内部,而且可以抑制可燃性气体向PVC膜外逸出。SEM和拉伸强度结果显示,双层微胶囊可有效改善无机粒子在PVC基体中的分散性和相容性。     

Implementation of ZnSnO3 nanosheets and their RE (Er,Eu, and Pr) materials: Enhanced photocatalytic activity

ZnSnO₃, ZnSnO₃@Er, ZnSnO₃@Eu, and ZnSnO₃@Pr materials were synthesized by a hydrothermal method, these active materials characterized by XRD, Raman, DRS-UV, FT-IR, BET surface areas and Scanning electron microscopy studies. The ZnSnO₃ nanosheets meta-stable form was confirmed by XRD. Here, addressing to the pure and doped materials functional groups were evaluated by FT-IR spectroscopy. ZnSnO₃, ZnSnO₃@Er, ZnSnO₃@Eu, and ZnSnO₃@Pr rotational vibrations frequency modes were predicted by the Raman spectroscopy. Our results are marvelously, the obtained bandgap energies at 3.5 eV for pure sample and ZnSnO₃@Er, ZnSnO₃@Eu and ZnSnO₃@Pr energies at 3.06 eV, 3.04 eV and 3.02 eV. The synthesized pure samples get a sheet-like morphology and doped for RE metals than morphology was changing for nanocubes. We assess for all samples that were focused on photocatalytic dye degradation for Methylene blue dye; hence, we are discussing these approaches, ZnSnO₃@Pr/Methylene blue sample was a great improvement and high decolorization efficiency compared with ZnSnO₃@Er, ZnSnO₃@Eu nanocubes. The ZnSnO₃@Pr sample surface area was investigated by BET analysis. In addition, we are testing the phenol degradation with wastewater. The ZnSnO₃@Er, ZnSnO₃@Eu catalysts were determined to the less efficiency when comparing to the ZnSnO₃@Pr material. The ZnSnO₃@Pr material results have more efficiency and a very good recyclable stability nature.     

Selective Formation of Carbon‐Coated,Metastable Amorphous ZnSnO3 Nanocubes Containing Mesopores for Use as High‐Capacity Lithium‐Ion Battery

Mesoporous and amorphous ZnSnO₃ nanocubes of ～37 nm size coated with a thin porous carbon layer have been prepared using monodisperse ZnSn(OH)₆ as the active precursor and low‐temperature synthesized polydopamine as the carbon precursor. The small single nanocubes cross‐link with each other to form a continuous conductive framework and interconnected porous channels with macropores of 74 nm width. Because of its multi‐featured nanostructure, this material exhibits greatly enhanced integration of reversible alloying/de‐alloying (i.e., transformation of Li_4.4Sn and LiZn to Sn and Zn) and conversion (i.e., oxidation of Sn and Zn to ZnSnO₃) reaction processes with an extremely high capacity of 1060 mA h g^?1 for up to 100 cycles. A high reversible capacity of 650 and 380 mA h g^?1 can also be delivered at rates of 2 and 3 A g^?1, respectively. This excellent electrochemical performance is attributed to the small particle size, well‐developed mesoporosity, the amorphous nature of the ZnSnO₃ and the continuous conductive framework produced by the interconnected carbon layers.     

Photostriction of CH3NH3PbBr3 Perovskite Crystals

Organic–inorganic hybrid perovskite materials exhibit a variety of physical properties. Pronounced coupling between phonon, organic cations, and the inorganic framework suggest that these materials exhibit strong light–matter interactions. The photoinduced strain of CH₃NH₃PbBr₃ is investigated using high‐resolution and contactless in situ Raman spectroscopy. Under illumination, the material exhibits large blue shifts in its Raman spectra that indicate significant structural deformations (i.e., photostriction). From these shifts, the photostrictive coefficient of CH₃NH₃PbBr₃ is calculated as 2.08 × 10^?8 m² W^?1 at room temperature under visible light illumination. The significant photostriction of CH₃NH₃PbBr₃ is attributed to a combination of the photovoltaic effect and translational symmetry loss of the molecular configuration via strong translation–rotation coupling. Unlike CH₃NH₃PbI₃, it is noted that the photostriction of CH₃NH₃PbBr₃ is extremely stable, demonstrating no signs of optical decay for at least 30 d. These results suggest the potential of CH₃NH₃PbBr₃ for applications in next‐generation optical micro‐electromechanical devices.     

Constitution of the Ni3Cr-Ni3Al-Ni3W system

Isothermal sections of the Ni-Cr-Al-W system have been investigated at 75 at % Ni and temperatures of 1523 and 1273 K, by means of phase compositional analysis, X-ray diffraction and microscopical examination. The alloys studied lay in the range 2.5 to 10 at % Cr, 12.5 to 20 at% Al, 2.5 to 6.25 at % W, The phases formed were, and the bcc solid solution based on tungsten (designated ₂). The maximum extent of the region was found to be 3 at % each of chromium and tungsten. Preferential partitioning of tungsten to occurred. Study of an Ni-10Cr-12.5Al-2.5W alloy aged at 1273 and 1073 K, after quenching from 1573 K, showed that changes in and compositions and lattice parameters occur as a function of ageing time.     

Crystal structure of Tl3AsSe3

The structure of Tl₃AsSe₃, which has been solved by the single-crystal x-ray method, is rhombohedral, with space group R3m and cell parameters $\text{a}\text{= 9.870(2)}\text{A}\text{?}\text{, c}\text{= 7.094(3)}\text{A}\text{?}\text{, z}\text{= 3}$. A full-matrix least-squares refinement gives weighted R = 0.058. The Se atoms form equilateral triangles around Tl at 3.178Å and around As at 2.207Å. The structure may be described in terms of units formed from three TlSe₃ triangles by corner-sharing. These units share corners to produce a helical arrangement along the c axis. The triangles of AsSe₃ are isolated from each other.