一种银掺杂的ZnO/ZnSnO3复合光催化剂的制备及其光催化性能

以Zn(NO3)2·6H2O和SnCl4·5H2O为原料,氨水为沉淀剂,利用沉淀一煅烧法结合光沉积法分别制备了ZnO、ZnSnO3、ZnO/ZnSnO3和Ag/ZnO/ZnSnO3单、双和3组分光催化剂.利用X射线衍射(XRD)、扫描电镜(SEM),紫外-可见漫反射光谱(UV-Vis)和X射线荧光光谱对样品进行了表征....     

薄片状C60/ZnO纳米复合材料的制备及其光催化性能

首先通过简单沉淀法制备了薄片状纳米ZnO,再利用化学吸附作用将C60与ZnO复合得到C60/ZnO纳米复合材料。采用XRD、SEM、XPS、Ra-man、DRS、PL等技术对样品进行表征,紫外光下以亚甲基蓝(MB)作为探针分子,研究C60/ZnO纳米复合材料的光催化活性。结果表明,C60/ZnO纳米复合材料的光催化活性优于单纯的纳米ZnO,且1%(质量分数)C60/ZnO的光催化活性最高,这是由于C60具有良好的接受和传导电子的作用,抑制了光生电子和空穴的复合,从而提高了光催化效率。     

Manganese dependence of microstructure and mechanical properties in Fe–Mn alloy

Two Fe–Mn alloys with relatively low Mn content were designed. The microstructure characteristics and resultant mechanical properties were investigated in detail by means of electron back-scattered diffraction, transmission electron microscopy and X-ray diffraction. The results show that the formation of α′-martensite is effectively suppressed and the yield strength and total elongation are significantly enhanced by increasing Mn content from 12 to 13 mass%. A great amount of α′-martensite can effectively enhance strain hardening rate, but they deteriorate ductility. The austenite grain is always divided by multiple-variant ?-martensite plate. In addition, the prior austenite grain boundaries and austenite/?-martensite interfaces can act as obstacle to suppress the growth of ?-martensite plates.     

Nonhierarchical Heterostructured Fe2O3/Mn2O3 Porous Hollow Spheres for Enhanced Lithium Storage

High capacity transition‐metal oxides play significant roles as battery anodes benefiting from their tunable redox chemistry, low cost, and environmental friendliness. However, the application of these conversion‐type electrodes is hampered by inherent large volume variation and poor kinetics. Here, a binary metal oxide prototype, denoted as nonhierarchical heterostructured Fe₂O₃/Mn₂O₃ porous hollow spheres, is proposed through a one‐pot self‐assembly method. Beyond conventional heteromaterial, Fe₂O₃/Mn₂O₃ based on the interface of (104)_Fe2O3 and (222)_Mn2O3 exhibits the nonhierarchical configuration, where nanosized building blocks are integrated into microsized spheres, leading to the enhanced structural stability and boosted reaction kinetics. With this design, the Fe₂O₃/Mn₂O₃ anode shows a high reversible capacity of 1075 mA h g^?1 at 0.5 A g^?1, an outstanding rate capability of 638 mA h g^?1 at 8 A g^?1, and an excellent cyclability with a capacity retention of 89.3% after 600 cycles.     

Micromagnetic simulation on magnetic properties of Nd2Fe14B/α-Fe nanocomposites with Fe nanowires as the soft phase

Fe nanowire array with strong shape anisotropy was employed as the soft phase in Nd–Fe–B based nanocomposites. The effects of the Fe nanowire distribution on magnetic properties of the nanocomposites were investigated by micromagnetic simulation. The results indicate that the shape anisotropy of Fe wires added in the same direction as the uniaxial magnetocrystalline anisotropy of the hard phase cannot increase the coercivity of the nanocomposite. When the nanowires are distributed perpendicular to the easy axis of the hard phase, the shape anisotropy of soft phase can retard the moments from rotating to the full reversed direction, leading to enhanced coercivity. In addition, with increasing the nanowire diameter, the coercivity of the nanocomposite decreases, but the dipolar interaction shows different roles in magnetic reversal of nanocomposite for different distributions of nanowires. The current results suggest that the coercivity of the Nd₂Fe₁₄B/α-Fe nanocomposite can be enhanced by introducing the soft magnetic nanowire array with the diameter less than the exchange length and with the long axis along the direction other than the easy axis of hard phase.     

Preparation of Co and Fe nanocomposites in SiO2 matrices

Cobalt and iron nanocomposites have been prepared by in situ reduction of metallic salts in SiO₂ gel matrices. The presence of nanosized metal phases has been established chemically as well as by selected area diffraction and transmission electron microstructural analyses. Studies on temperature and time dependent fractional reduction revealed that the reduction kinetics are fast.     

TiO2/Fe2O3复合光催化超亲水性薄膜的研究

采用溶胶-凝胶法及浸渍提拉法在普通的载玻片上制得了TiO2/Fe2O3复合薄膜,通过对薄膜及相应干凝胶和粉体的DSC、XRD、UV透射光谱等的测量,分析了Fe2O3的含量对TiO2/Fe2O3复合薄膜的光催化及超亲水性能的影响.结果表明:复合薄膜均优于纯TiO2薄膜的光催化活性,Fe2O3的摩尔含量为0.5%时光催化活性最好;复合薄膜的亲水性能也随Fe2O3含量的不同而不同,Fe2O3的摩尔含量为0.05%～0.1%时得到了接触角为0°的超亲水性复合薄膜.     

Synthesis of Fe/SiO2 composite particles and their superior electromagnetic properties in microwave band

Fe/SiO₂ composite particles were synthesized by hydrogen reduction of Fe₂O₃/SiO₂ precursor, which was prepared by sol-gel method. A reduction temperature higher than 600 °C is required for the complete conversion of Fe₂O₃ to Fe. Fe/SiO₂ composite particles exhibit superior complex permittivity and permeability in the microwave band. A reflection loss higher than − 70 dB as well as a broad absorption band can be simultaneously obtained for Fe/SiO₂-based coatings about 2 mm in thickness, suggesting that the Fe/SiO₂ composite particles are a promising candidate for high performance electromagnetic absorption materials.     

Study on the structure and properties of core–shell Fe/Al composite powder synthesized by MOCVD in fluidized bed

Core–shell Fe/Al composite powder with different thicknesses of Fe layer has been prepared by MOCVD in a fluidized bed reactor. The products were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectrometer (EDX) and simultaneous thermogravimetry–differential scanning calorimetry (TG–DSC). The results show that a compact nano-Fe layer is covered on the surface of Al to form core–shell Fe/Al composite powder. Nano-Fe layer thickness can be controlled by adjusting deposition time. The Fe layer thickness is evaluated by weight increase in TG curve at the temperature range of 350–550 °C in air atmosphere. Combustion properties of Fe/Al composite powder have great improvement compared with raw Al.