WS2/CuGa2O4复合材料的制备及其气敏性

采用共沉淀法制备了CuGa₂O₄纳米材料,并利用水热法制备了一系列WS₂/CuGa₂O₄复合材料。结合X射线衍射(XRD)、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)等对制备的材料进行了物相组成、表面形貌以及元素价态的分析。研究了WS₂的复合量对 CuGa₂O₄材料检测乙醇气体敏感性能的影响。实验结果表明,当 WS₂与 CuGa₂O₄质量比为 1%时,该复合材料制备的传感器在室温下对 100 μL·L^-1乙醇气体表现出 345.3 的灵敏度,响应时间和恢复时间分别为 184 和 69 s,且最低检测限为 0.1μL·L^-1。     

WS2/CuGa2O4复合材料的制备及其气敏性

采用共沉淀法制备了CuGa₂O₄纳米材料,并利用水热法制备了一系列WS₂/CuGa₂O₄复合材料。结合X射线衍射(XRD)、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)等对制备的材料进行了物相组成、表面形貌以及元素价态的分析。研究了WS₂的复合量对CuGa₂O₄材料检测乙醇气体敏感性能的影响。实验结果表明,当WS₂与CuGa₂O₄质量比为1%时,该复合材料制备的传感器在室温下对100μL·L^-1乙醇气体表现出345.3的灵敏度,响应时间和恢复时间分别为184和69 s,且最低检测限为0.1μL·L^-1。     

Fabrication and photoelectrochemical properties of porous ZnWO4 film

Porous ZnWO₄ films have been fabricated on Indium-tin oxide (ITO) glass and its photoelectrochemical properties and high photocatalytic activities towards degradation of rhodamine B (RhB) has been investigated. Using amorphous heteronuclear complex as precursor and with the addition of polyethylene glycol (PEG, molecular weight=400), the porous ZnWO₄ films have been achieved at the temperature of 500 °C via dip-coating method. It is composed of approximately 70 nm-sized particles and exhibits substantial porosity. The textures and porosity of ZnWO₄ films are dependent on preparation factors, such as the ratio of precursor/PEG and the annealing conditions. The formation mechanism of porous ZnWO₄ films was proposed. The porous ZnWO₄ films exhibited high photocatalytic activities towards degrading RhB. The top of valence band and the bottom of the conduction band was estimated to be −0.56 and 3.45 eV (vs. saturated calomel electrode (SCE)), respectively.     

Supramolecular aggregation in new crystals with nonlinear optical properties: 2-aminophenol-HClO4, 3-aminophenol-HClO4 and 4-aminophenol-HClO4

Three new hybrid crystals of 2-aminophenol-HClO₄ (2-AP-HClO₄, 1), 3-aminophenol-HClO₄ (3-AP-HClO₄, 2) and 4-aminophenol-HClO₄ (4-AP-HClO₄, 3) were obtained and their crystal structures determined. The 1 crystallises in centrosymmetric space group C2/c of monoclinic system while the other two (2 and 3) crystallise in the non-centro symmetric space group P2₁ and P2₁2₁2₁, respectively. The oppositely charged units of the crystals, i.e. positively charged 2-APH⁺, 3-APH⁺ and 4-APH⁺ and ClO₄⁻, interact via weak N⁺–HO and O–HO hydrogen bonds forming 3D-supramolecular network. Relative to KDP the SHG efficiencies are 0.62 for 2 and 0.33 for 3, measured at 1064 nm using the Kurtz–Perry method.     

Pt / InVO4 / TiO2可见光催化剂的制备及性能研究

采用溶胶-凝胶法制备了Pt / InVO₄ / TiO₂三元体系可见光催化剂。以乙烯为模拟目标分子，评价其光催化活性并与二元体系催化剂Pt / TiO₂ 和InVO₄ / TiO₂进行比较。用DRS，XRD对催化剂的吸收带边和晶型进行了表征。结果表明：Pt / InVO₄ / TiO₂在可见光区（λ>450 nm）的光催化比活性比Pt / TiO相似文献   

一维纳米Co_3O_4,Ag/Co_3O_4及CuO/Co_3O_4的合成与电催化性能(英文)

采用水热合成法制备了Co3O4及复合Ag/Co3O4、CuO/Co3O4一维纳米产品。用XRD,FE-SEM和TEM手段对产品进行了表征。采用循环伏安法研究了合成产品修饰的玻碳电极在碱性溶液中对对硝基苯酚的电催化还原性能。与裸玻碳电极相比,1mmol·L-1的对硝基苯酚在用Co3O4、特别是CuO/Co3O4修饰的玻碳电极上还原的峰电流明显增大,用Ag/Co3O4(Ag/Co原子比分别为1∶5和2∶5)修饰的玻碳电极催化还原对硝基苯酚时,尽管还原峰电流增大不是太大,但其峰电位明显降低(分别降低0.265和0.371V)。     

对BiVO4/BiPO4复合物可见光催化活性提高的研究

采用水热法合成出具有不同V、P物质的量之比的BiVO₄/BiPO₄复合物.n_V/n_P分别为:0.1/9.9、0.5/9.5、1/9、3/7、5/5.采用 XRD、FE-SEM、EDS、拉曼、可见光光度计、漫反射以及电化学等测试手段对BiVO₄/BiPO₄复合物进行表征.在可见光条件下降解亚甲基蓝来评价BiVO₄/BiPO₄复合物的光催化活性.结果显示,当n_V/n_P<3/7的时候,BiVO₄/BiPO₄复合物的光催化活性随着BiVO₄含量的增加而增加,当n_V/n_P=3/7的时候,复合物具有最佳的光催化性能,反应速率常数k为0.005 1 min^-1,是纯BiPO₄的23.2倍.BiVO₄/BiPO₄复合物的光催化机制主要是由于BiVO₄的加入,提高了电子-空穴的分离率,进而提高了光催化活性.     

BiVO4/BiPO4复合物的制备及可见光催化性能

采用水热法合成出具有不同V、P物质的量之比的BiVO₄/BiPO₄复合物.n_V/n_P分别为:0.1/9.9、0.5/9.5、1/9、3/7、5/5.采用 XRD、FE-SEM、EDS、拉曼、可见光光度计、漫反射以及电化学等测试手段对BiVO₄/BiPO₄复合物进行表征.在可见光条件下降解亚甲基蓝来评价BiVO₄/BiPO₄复合物的光催化活性.结果显示,当n_V/n_P<3/7的时候,BiVO₄/BiPO₄复合物的光催化活性随着BiVO₄含量的增加而增加,当n_V/n_P=3/7的时候,复合物具有最佳的光催化性能,反应速率常数k为0.005 1 min^-1,是纯BiPO₄的23.2倍.BiVO₄/BiPO₄复合物的光催化机制主要是由于BiVO₄的加入,提高了电子-空穴的分离率,进而提高了光催化活性.     

Ultrasonic synthesis of polyaniline nanotubes containing Fe3O4 nanoparticles

Polyaniline (PANI) nanotubes containing Fe₃O₄ nanoparticles were synthesized under ultrasonic irradiation of the aqueous solutions of aniline, ammonium peroxydisulfate (APS), phosphoric acid (H₃PO₄), and the quantitative amount of Fe₃O₄. It was found that the obtained samples had the morphologies of nanotubes. TEM images and selected area electronic diffractions showed that Fe₃O₄ nanoparticles were embedded in PANI nanotubes. We thought that the mechanism of the formation of PANI/Fe₃O₄ nanotubes could be attributed to the ultrasonic irradiation and the H₃PO₄-aniline salt template. The molecular structure of PANI/Fe₃O₄ nanotubes were characterized by Fourier transform infrared spectroscopy (FTIR), UV-vis absorption spectra and X-ray diffraction (XRD). The conductivity and magnetic properties of the PANI nanotubes containing Fe₃O₄ nanoparticles were also investigated.     

Cr2(WO4)3和Cr2(MoO4)3的负热膨胀特性研究

用液相反应-前驱物烧结法制备了Cr₂(WO₄)₃和Cr₂(MoO₄)₃粉体。298～1 073 K的原位粉末X射线衍射数据表明Cr₂(WO₄)₃和Cr₂(MoO₄)₃的晶胞体积随温度的升高而增大, 本征线热膨胀系数分别为(1.274±0.003)×10^-6 K^-1和(1.612±0.003)×10^-6 K^-1。用热膨胀仪研究了Cr₂(WO₄)₃和Cr₂(MoO₄)₃在静态空气中298～1 073 K范围内热膨胀行为，即开始表现为正热膨胀，随后在相转变点达到最大值，最后表现为负热膨胀，其负热膨胀系数分别为(-7.033±0.014)×10^-6 K^-1和(-9.282±0.019)×10^-6 K^-1。     

Investigations on the solid state interaction between LiAlH4 and NaNH2

In this paper, two LiAlH₄-NaNH₂ samples with LiAlH₄ to NaNH₂ molar ratio of 1/2 and 2/1 were investigated, respectively. It was observed that both samples evolved 2 equiv H₂ in the ball milling process, however, the reaction pathways were different. For the LiAlH₄-NaNH₂ (1/2) sample, Li₃Na(NH₂)₄ and NaAlH₄ were formed through cation exchange between reactants. The NaAlH₄ formed further reacts with Li₃Na(NH₂)₄ and NaNH₂ to give H₂, NaH and LiAlN₂H₂. For the LiAlH₄-NaNH₂ (2/1) sample, Li₃Na(NH₂)₄, LiNH₂ and NaAlH₄ were formed firstly through the same cation exchange process. The resulting LiNH₂ reacts with the remaining LiAlH₄ and produces H₂ and Li₂AlNH₂.     

MgAl2O4尖晶石对锂离子电池正极材料LiMn2O4的循环性能影响研究

MgAl₂O₄ spinel doping into cathode materials LiMn₂O₄ was used to improve the cyclic performance of the cathode. X-ray analysis results showed, when MgAl₂O₄ precursors were mixed with LiMn₂O₄ and sintered at 770 ℃ for 12 hour, MgAl₂O₄-LiMn₂O₄ mulriple spinel with the same physical characteristics as pure LiMn₂O₄ were synthesized. The electro-chemical performance testing showed, comparing with pure LiMn₂O₄, the first charge-discharge capacity of doping materials somewhat reduced, but the cyclic performance improved. The mechanism for doping material was also discussed.     

Pt/g-C3N4/KB纳米复合催化剂的制备及其甲醇氧化性能

采用溶液中等离子放电法制备出了Pt纳米颗粒,用热氧化刻蚀和水热法成功的对石墨相氮化碳（g-C₃N₄）进行处理进而均匀吸附在科琴黑（KB）表面,最终制备出了Pt/g-C₃N₄/KB纳米复合催化剂。通过XRD分析,扫描电镜,透射电镜和电化学工作站探究了催化剂的组成、结构、颗粒大小以及电化学性能。Pt/g-C₃N₄/KB纳米复合催化剂展现出了良好的甲醇电氧化性能,性能的提升可能是由于g-C₃N₄良好的化学稳定性,N元素的存在改变Pt外层电子结构从而提高催化活性,这些因素提高了Pt的催化效率。     

Pt/g-C_3N_4/KB纳米复合催化剂的制备及其甲醇氧化性能

采用溶液中等离子放电法制备出了Pt纳米颗粒,用热氧化刻蚀和水热法成功的对石墨相氮化碳(g-C_3N_4)进行处理进而均匀吸附在科琴黑(KB)表面,最终制备出了Pt/g-C_3N_4/KB纳米复合催化剂。通过XRD分析,扫描电镜,透射电镜和电化学工作站探究了催化剂的组成、结构、颗粒大小以及电化学性能。Pt/g-C_3N_4/KB纳米复合催化剂展现出了良好的甲醇电氧化性能,性能的提升可能是由于g-C_3N_4良好的化学稳定性,N元素的存在改变Pt外层电子结构从而提高催化活性,这些因素提高了Pt的催化效率。     

Temperature behavior of the protonic conductor K4LiH3(SO4)4

The results of the X-ray structural study for the K₄LiH₃(SO₄)₄ single crystal are presented at a wide temperature range. The thermal expansion of the crystal using the X-ray dilatometry and the capacitance dilatometry from 8 to 500 K was carried out. The crystal structures data collection, solution and refinement at 125, 295, 443 and 480 K were performed. The K₄LiH₃(SO₄)₄ crystal has tetragonal symmetry with the P4₁ space group (Z=4) at room temperature as well as at the considered temperature range. The existence of a low-temperature, para-ferroelastic phase transition at about 120 K is excluded. The layered structure of the crystal reflects a cleavage plane parallel to (001) and an anisotropy of the protonic conductivity. The superionic high-temperature phase transition at T_S=425 K is isostructural. Nevertheless, taking into account an increase of the SO₄ tetrahedra libration above T_S, a mechanism of the Grotthus type could be applied for the proton transport explanation.     

可见光响应的Co3(PO4)2/Ag3PO4纳米复合光催化剂的制备及表征

采用简单的化学偏聚法合成出Ag₃PO₄纳米颗粒、磷酸钴（Co₃（PO₄）₂,CoP）纳米片以及它们两者的纳米复合结构（CoP/Ag₃PO₄）,同时还比较了它们的可见光催化活性. 采用场发射扫描电镜（FESEM）、X 射线衍射（XRD）、紫外-可见（UV-Vis）吸收光谱以及光致发光谱等手段对其形貌、结构、光学以及可见光催化性能等进行表征. 结果表明,CoP/Ag₃PO₄复合纳米结构的可见光降解甲基橙（MO）的速率和循环稳定性均明显优于其它两种物质. 这表明CoP应该起着共催化剂的作用,它能够抑制光生电子与空穴之间的复合,并且提供大量高活性的光生空穴. 此外,我们还发现CoP/Ag₃PO₄降解另一种阳离子型染料——罗丹明B（RhB）的能力则远不如纯Ag₃PO₄,这可能是与光催化剂的表面性质发生改变有关,造成更低的RhB吸附能力. 本文提供了一种廉价制备高效可见光催化剂的新方法.     

水热法制备LiMnPO4包覆的LiMn2O4正极材料及其改善的电化学特性

通过水热合成的方法制备了不同质量百分比的LiMnPO4包覆LiMn2O4的复合材料,并且利用XRD、拉曼光谱、SEM、TEM以及充放电测试等手段,对其结构和电化学性能进行了表征。研究表明,适当量的LiMnPO4包覆,不仅可以增加材料的可逆比容量,还可以有效提高材料在55℃下的循环特性。1wt%LiMnPO4包覆的LiMn2O4在55℃下的可逆容量为109 mAh.g-1,是其初始容量的96%。此外,1wt%LiMnPO4包覆的LiMn2O4与未包覆的LiMn2O4相比,在倍率特性上也有明显的改善。     

Origin of the improved photo-catalytic activity of F-doped ZnWO4: A quantum mechanical study

Two different mechanisms for improving photo-catalytic activity in different types of F-doped ZnWO₄ are tentatively proposed, based on density function theory calculations. When the lattice O atom is substituted by one F atom, our calculations show that a reduced W⁵⁺ center adjacent to the doped F atom will act as a trap for the photo-induced electron, and will thus result in a reduction of electron-hole recombination and improvement of the photo-catalytic activity. For the interstitial F-doped model, partial F 2p states mixing with O 2p states localize above the top of the valence band and act as the frontier orbital level. Electronic transitions from these localized states induce a red shift of about 54 nm of the optical absorption edge. This work shows that F-doped ZnWO₄ will be a promising photo-catalyst with favorable photo-catalytic activity in the UV region.     

Structure and magnetism of NaRu2O4 and Na2.7Ru4O9

The structures of NaRu₂O₄ and Na_2.7Ru₄O₉ are refined using neutron diffraction. NaRu₂O₄ is a stoichiometric compound consisting of double chains of edge sharing RuO₆ octahedra. Na_2.7Ru₄O₉ is a non-stoichiometric compound with partial occupancy of the Na sublattice. The structure is a mixture of single, double and triple chains of edge-shared RuO₆ octahedra. NaRu₂O₄ displays temperature independent paramagnetism with . Na_2.7Ru₄O₉ is paramagnetic, χ₀= with and a Curie constant of 0.0119 emu/mol Oe K. Specific heat measurements reveal a small upturn at low temperatures, similar to the upturn observed in La₄Ru₆O₁₉. The electronic contribution to the specific heat (γ) for Na_2.7Ru₄O₉ was determined to be15 mJ/mole_Ru K².     

BiVO4/ZnFe2O4同型异质结光阳极的构筑及其光电催化分解水性能

光生电子-空穴对的复合被认为是限制BiVO₄材料光电催化转换效率的重要原因之一。基于此,通过简单的水热-煅烧方法构筑了BiVO₄/ZnFe₂O₄同型异质结光阳极,BiVO₄/ZnFe₂O₄复合光阳极在1.23 V(vs RHE)下的光电流密度为3.33 mA·cm^-2,较纯BiVO₄提升了2倍(1.20 mA·cm^-2)。相关的结构及性能测试表明,BiVO₄和ZnFe₂O₄形成了带隙错开的n-n异质结,使得光生载流子得到有效分离,更有效地参与水氧化过程,进而提高了BiVO₄的光电催化水分解性能。