【无机化学学报】doi: 10.11862/CJIC.20230403
利用乙二胺-水蒸汽进行气相转化(VPT)制备超薄、取向MFI沸石膜,通过将MFI纳米片沉积层转化为致密的沸石膜,实现了膜厚度的有效控制。扫描电子显微镜和X射线衍射表明,制备的沸石膜膜厚度约为280 nm,具有高度b轴取向的致密结构。丁烷异构体双组分分离测试结果表明,在333 K下,等物质的量的正丁烷/异丁烷混合物的正丁烷渗透速率和分离因子分别为1.5×10-7 mol·m-2·s-1·Pa-1和14.8。Na2SiO3作为低聚硅源在MFI沸石纳米片二次生长过程中能够提供硅源和碱度,通过在胺类蒸汽中实现MFI沸石纳米片间的融合生长,进一步提高了膜的取向度和致密性。
【无机化学学报】doi: 10.11862/CJIC.20240255
采用原位聚合法制备了氯氧化铋(BiOCl)与聚苯胺(PANI)复合的Ⅱ型异质结光催化剂BiOCl/PANI,并采用X射线衍射(XRD)、傅里叶变换红外光谱(FTIR)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)、紫外可见漫反射光谱(UV-Vis DRS)和N2吸附-脱附测试等多种技术手段对其进行了表征,考察了BiOCl/PANI在模拟可见光下对罗丹明B (RhB)的光催化降解性能。实验结果表明:BiOCl/PANI催化剂比PANI和BiOCl具有更高的光催化活性,在RhB质量浓度为50 mg·L-1、PANI与BiOCl的物质的量之比为0.02∶1、50 mg·L-1的催化剂条件下,所制备的BiOCl/PANI光催化150 min后,RhB降解率为98.8%,速率常数为0.031 min-1;经过4次循环实验后,RhB降解率从98.8%降低至98.4%,表现出良好的稳定性和可重复利用性。光催化剂BiOCl/PANI实现了电子和空穴对的快速分离,降低了二者在催化剂内部的复合速率,提高了光催化性能。
【无机化学学报】doi: 10.11862/CJIC.20240219
A simple two-step hydrothermal method synthesized four different CdS/Fe3O4 photocatalysts with varying ratios of mass of CdS to Fe3O4. The composition and morphology of the prepared samples were investigated using X-ray diffraction (XRD), Raman spectrum, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Solid UV reflectance spectra testing found that CdS/Fe3O4 nanocomposites had good light absorption throughout the spectral range, promoting their photocatalytic properties. Under visible light irradiation, CdS/Fe3O4 (2:5) with a mass ratio of 2:5 exhibited excellent photocatalytic performance, with a degradation rate of 98.8% for rhodamine B. Furthermore, after five cycles of photocatalytic degradation reaction, the rhodamine B degradation rate remained at 96.2%, indicating that the photocatalysts have good photocatalytic stability.
【无机化学学报】doi: 10.11862/CJIC.20240390
This paper delves into the theoretical mechanisms of the electronic structure and optical properties of aluminum-based semiconductors (AlX, X=N, P, As, Sb) and indium-based semiconductors (InX, X=N, P, As, Sb) as potential materials for optical devices. Band structure calculations reveal that, except for InSb, all other compounds are direct bandgap semiconductors, with AlN exhibiting a bandgap of 3.245 eV. The valence band maximum of these eight compounds primarily stems from the p-orbitals of Al/In and X. In contrast, the conduction band minimum is influenced by all orbitals, with a predominant contribution from the p-orbitals. The static dielectric constant increased with the expansion of the unit cell volume. Compared to AlX and InX with larger X atoms, AlN and InN showed broader absorption spectra in the near-ultraviolet region and higher photoelectric conductance. Regarding mechanical properties, AlN and InN displayed greater shear and bulk modulus than the other compounds. Moreover, among these eight crystal types, a higher modulus was associated with a lower light loss function value, indicating that AlN and InN have superior transmission efficiency and a wider spectral range in optoelectronic material applications.
【物理化学学报】doi: 10.3866/PKU.WHXB202310029
碲化锰(manganese telluride,MnTe)作为一种新兴的非层状二维材料,因其优异的性质以及在下一代电子和光电子器件中的巨大潜力,而受到研究学者们的广泛关注。然而,目前超薄二维MnTe的可控合成仍然是一个巨大的挑战,这限制了对其基础性质的研究和应用的深入探索。本文采用化学气相沉积方法成功合成了大面积的MnTe纳米片,并探究了其厚度对电学性质和器件应用的影响。通过提高MnTe纳米片的生长温度,样品厚度逐渐增加,晶畴尺寸从10 μm增至125 μm,形貌从三角形逐渐过度到六边形,最终生长成高度对称的圆形。结构表征和二次谐波测试表明,所制备的MnTe纳米片具有高度的结晶质量和优异的二阶非线性光学性质。此外,通过对不同厚度MnTe纳米片的电学输运测试,发现随着厚度从薄到厚,其导电特性从p型半导体逐渐转变为半金属。因此,利用半导体特性的薄层MnTe纳米片构建的光电探测器展现出出色的光响应性能。而将金属特性的厚层MnTe作为MoS2场效应晶体管的接触电极,显著提高了器件性能,如载流子迁移率可从12.76 cm2∙V−1∙s−1 (Au接触)提升到47.34 cm2∙V−1∙s−1 (MnTe接触)。
【大学化学】doi: 10.12461/PKU.DXHX202406085
苯(C6H6)与二十面体硼烷(B12H122-)是具有π-和σ-芳香性分子的典型代表。本实验采用密度泛函理论(DFT)分别计算二者的分子轨道图及核独立化学位移值,引导学生了解计算化学研究芳香性的一般方法,构建对电子离域结构的直观认知。通过对比分析,帮助学生加深对芳香性的理解,达到巩固基础,拓宽视野,提升创新技能的目的。实验普适性好,易于推广。