不锈钢在含有溴离子的醋酸溶液中的腐蚀

采用浸泡试验及电化学试验,对304、254 SMO和HastelloyC－276三种材料在醋酸和含有Br^-离子的醋酸溶液中的腐蚀行为进行了测试。用SEM和XPS分析点蚀形貌。结果发现材料表面所形成的钝化膜中含有Cr2O3和MoO2,对材料起保护作用。     

两种不同石墨电极上溴离子电氧化的研究

通过测定溴离子在两种不同石墨电极上的循环伏安曲线及电流效率,探索了溴离子在石墨电极上氧化的电解条件,比较了两种石墨电极对溴离子电氧化的影响。研究发现,由于电极材料的不同和析氧反应的存在,两种电极材料对溴离子氧化的催化作用有一定差别。溴离子在石墨电极上氧化的电流效率一般在80％以上,最高可达88.5％。     

用密度泛函理论研究多溴二苯并噻吩的热力学性质

The thermodynamic properties of 135 polybrominated dibenzothiophenes (PBDTs) in the gaseous state at 298.15 K and 1.013×105 Pa, are calculated using the density functional theory (the B3LYP/6-311G**) with Gaussian 03. Based on these data, the isodesmic reactions are designed to calculate the standard enthalpy of formation (ΔfHө) and the standard Gibbs energy of formation (ΔfGө) of PBDTs. The relations of these thermodynamic parameters with the number and position of bromine substituents (NPBS) are discussed, and it is found that there exist good correlations between thermodynamic parameters (including heat capacity at constant volume, entropy, enthalpy, free energy, ΔfHө, ΔfGө) and NPBS. The relative stability order of PBDT congeners is proposed theoretically based on the relative magnitude of their ΔfGө. In addition, the values of molar heat capacities at constant pressure (Cp,m) for PBDT congeners are calculated.     

Self-Powered Red/UV Narrowband Photodetector by Unbalanced Charge Carrier Transport Strategy

Narrowband photodetector (NB-PD) with selective light detection is critical for artificial vision and imaging. Intrinsic (optical-filter-free) NB-PDs using conjugated organics or halide perovskite materials have been developed for eliminating the current complex filtering systems in NB-PDs. However, the poor performance and external driving circuit of organic NB-PDs as well as complex doping and uncontrollable recombination reactions in typical perovskite NB-PDs have limited their applicational diversification. A p-type self-doped perovskite for intrinsic NB detection is reported which exhibits unique unbalanced electron–hole transfer kinetics. In conjunction with the optical field distribution, an unbalanced charge transport within the self-doped perovskite triggers a wavelength-dependent photo-carrier collection, resulting in a novel spontaneous internal quantum efficiency narrowing mechanism. As a result, by reverting the device architectural polarity, an NB detection at a monochromic light of either red or UV is observed. Using such a revertible asymmetric device design, self-powered NB-PDs are successfully achieved. Briefly, the corresponding NB-PDs exhibit excellent narrow response with a response window of ≈100 nm, high detectivity ≈10¹¹ Jones, and fast response speed (f_−3dB ≈ 60 kHz) at zero bias. These results demonstrate a new strategy of manipulating internal charge transport to realize power-free and filter-free intrinsic NB-PDs.     

Controlled n‐Doping in Air‐Stable CsPbI2Br Perovskite Solar Cells with a Record Efficiency of 16.79%

Cesium‐based inorganic perovskites, such as CsPbI₂Br, are promising candidates for photovoltaic applications owing to their exceptional optoelectronic properties and outstanding thermal stability. However, the power conversion efficiency of CsPbI₂Br perovskite solar cells (PSCs) is still lower than those of hybrid PSCs and inorganic CsPbI₃ PSCs. In this work, passivation and n‐type doping by adding CaCl₂ to CsPbI₂Br is demonstrated. The crystallinity of the CsPbI₂Br perovskite film is enhanced, and the trap density is suppressed after adding CaCl₂. In addition, the Fermi level of the CsPbI₂Br is changed by the added CaCl₂ to show heavy n‐type doping. As a result, the optimized CsPbI₂Br PSC shows a highest open circuit voltage of 1.32 V and a record efficiency of 16.79%. Meanwhile, high air stability is demonstrated for a CsPbI₂Br PSC with 90% of the initial efficiency remaining after more than 1000 h aging in air.     

Adsorption of 2-X-benzoic acids (X = fluoro, chloro, and bromo) on Au(1 0 0) electrode in acidic media studied by IRAS

Adsorption behaviors of 2-fluoro-, 2-chloro-, and 2-bromobenzoic acids on Au(1 0 0) electrode in 0.1 M HClO₄ have been investigated by using in situ reflection adsorption IR spectroscopy and differential capacity measurements. It is found for the 2-substitued benzoic acids that the flat lying adsorbed species is present at negative potentials, and the vertically adsorbed benzoate with both oxygen atoms oriented toward the metal surface is present at positive potentials. A new adsorbed state due to the vertical orientation was observed around 0.75 V only in 2-fluorobenzoic acid solution, as well as the case of benzoic acid. This indicates that the new band is due to the formation of an ordered adsorption layer of the vertical 2-fluorobenzoate, and the formation of the arrangement adsorption is dependent on the size of the adsorbed molecule.     

超分子化合物CdBr4（DPT）的合成与结构表征

用正溴丁烷和4,4’-联吡啶合成了新型的有机阳离子──1,1’-二丁基-4,4’-联吡啶(DPT.Br2),有机阳离子DPT.Br2又与金属盐CdBr2组装成了结构新颖的单核超分子化合物CdBr4(DPT)。通过红外光谱、荧光光谱、X-衍射仪等,表征了CdBr4(DPT)的光谱特征,并解出了其晶体结构。     

酸性介质中溴离子阳极氧化动力学研究

在酸性溶液中，使用旋转圆盘电极，研究了溴离子电极氧化反应的动力学特性。首先根据循环安曲线，定性地推断出两种可能的反应机理，然后对稳态极化数据非线回归离子该过程的反应机理及动力学参数。     

新世纪前10年全球阻燃剂发展预测

阻燃剂与其他塑料添加剂大不相同,它恶化塑料性能、增加塑料加工难度、缩短塑料使用寿命、提高塑料成本,但在遇到火灾时,却可减少人员伤亡和财产损失。卤系阻燃剂由于其显著的地位及寻找替代品的困难,在今后10年内仍将保持3%～4%的年增长率;磷-氮系阻燃剂由于其具有一系列的优点,将被积极开发和应用;氮基阻燃剂会受到青睐;抑烟剂的年均增长率将达6%左右。