Epitaxial Cd2SnO4 films were fabricated on MgO(00l) single crystalline substrates by pulsed laser deposition technique at various substrate temperatures and growth oxygen pressures. The microstructure, transport, and optical properties of the films were studied in detail. High-resolution X-ray diffraction and high-resolution transmission electron microscopy results demonstrate that all the Cd2SnO4 films are grown epitaxially on MgO(00l) substrates. Atomic force microscope images indicate that the films have smooth surface morphologies. Hall-effect measurements reveal that the epitaxial film grown at 680°C and 40 Pa presents the minimum resistivity value of 0.61 mΩcm and maximal Hall mobility of 32.87 cm2 V−1 s−1. The metal–semiconductor transitions of Cd2SnO4 films were observed and explained by competitive effects of two conductive mechanisms. The optical transmittance of the Cd2SnO4 films is higher than 75% in the visible and near-infrared range, and the optical bandgap was determined to be about 3.09 eV for the film grown at optimal condition. The band structure and density of states of the Cd2SnO4 were calculated by the density functional theory. 相似文献
Membrane technology features inspiring excellence from numerous separation technologies for CO2 capture from post-combustion gas. Polyvinylamine (PVAm)-based facilitated transport membranes show significantly high separation performance, which has been proven promising for industrial scale-up. However, commercialized PVAm with low molecular weight and excessive crystallinity is not available to prepare high-performance membranes. Herein, the synthesis process of PVAm was optimized by regulating polymerization and acidic hydrolytic conditions. The membranes based on PVAm with a molecular weight of 154 kDa and crystallinity of 11.37% display high CO2 permeance of 726 GPU and CO2/N2 selectivity of 55 at a feed gas pressure of 0.50 MPa. Furthermore, we established a PVAm synthesis reactor with an annual PVAm solution (1%(mass)) capacity of over 7000 kg and realized the scaled-up manufacture of both PVAm and composite membranes. 相似文献
在传统选择性催化还原技术(SCR)催化剂的基础上,分别以钒-钛系催化剂、固溶体催化剂和新型MnO x 催化剂为重点介绍了近些年低温SCR催化剂的研究进展,综述了不同活性组分的复合型催化剂的制备方法、元素掺杂、反应机理和抗性等,并通过分析不同复合型催化剂的表征总结了催化剂的性能状况以及低温脱硝效率,着重阐述了新型MnO x 催化剂所具有的优异脱硝特性,认为通过改性提高新型MnO x 的抗水抗硫性将会成为该领域未来的发展方向和研究热点,最后介绍了不同负载体对新型MnO x 催化剂的催化效率的影响规律,发现二氧化钛负载体具有良好的抗水性,三氧化二铝负载体能显著增强催化活性,二氧化铈负载体的热稳定性较好。 相似文献
Hydroxyapatite (HAP) is a common bio-adsorbent, which performance depends heavily upon its morphology and microporous structure. In this study, a novel synthesis strategy was proposed for hierarchical porous HAP microspheres by a simple “one-pot” hydrothermal reaction. In the strategy, L-glutamic acid serves as soft template to modulate the morphology and inner crystalline of HAP. To evaluate the application potential, doping Ni2+ on hierarchical porous HAP microspheres gives metal chelated affinity adsorbents. The prepared adsorbents show a perfect spherical shape, particles size of 96.6 μm, relatively specific surface area of 48.5 m2·g-1 and hierarchical pores (mesopores: 4 nm and macropores: 53 nm). By the adsorption evaluation, it reveals that the Ni2+-HAP adsorbents have high adsorption capacities of 275.11 and 97.55 m2·g-1 for hemoglobin and bovine serum albumin, respectively, which is comparable to other similar adsorbent. Therefore, this work provides a promising method for high-efficiency hydroxyapatite microspheres for proteins purification. 相似文献
Three novel orange emission supramolecular phosphorescent polymers (SPPs) with cationic iridium complex have been developed for polymer light-emitting diodes (PLEDs) through efficient self-assembly. The supramolecular assembly process was monitored by 1H nuclear magnetic resonance (1H NMR) and viscosity measurement. These SPPs give orange phosphorescence with a peak at about 595 nm and display good thermal properties with a glass-transition temperature (Tg) about 90 °C. The single-emissive-layer PLEDs with charged SPPs exhibited the highest device efficiency of 2.81 cd A?1 with the Commission Internationale de L’Eclairage coordinates of (0.58, 0.40). The present work reported the charged SPPs self-assembled by the cationic iridium complex for the first time and provided a new guide to develop orange emitters for solution-processable optoelectronic devices.
3D-printed SiC ceramics were prepared by direct ink writing and solid-phase sintering. The effects of sintering temperature, solid loading, and carbon additive on microstructures and mechanical properties of 3D-printed SiC parts were investigated. It was found that the sintering temperature affected the evolution of the microstructure and mechanical properties of the sintered SiC parts. A high solid loading promoted the densification and mechanical properties of the sintered SiC parts. However, the solid loading exceeded 40 vol.%, which decreased the density and mechanical properties of the samples. The carbon additives could improve the densification of the SiC parts and enhance their mechanical properties. When the sucrose content increased from 0 to 8 wt.%, the open porosity of the SiC part decreased from 26.12% to 3.15%, whereas the flexural strength increased 2.19 times. Using the optimized components and process parameters, the high-performance 3D-printed SiC parts were achieved. 相似文献