超声波辅助法一步合成B 酸离子液体

采用超声波辅助法一步合成了对水稳定性好和带—SO₃H官能团的吡啶磺酸类B酸离子液体,用核磁共振(NMR)对制备的离子液体进行表征。结果表明,超声波辐射法具有操作简单、条件温和、反应时间短和收率高等优点。在超声辐射时间120 min、超声功率200 W和超声温度30 ℃条件下,离子液体收率达92%。     

离子液体催化合成乙二醇双丙烯酸酯

使用酸性离子液体［Hnmp］HSO₄作为合成乙二醇双丙烯酸酯的催化剂,考察了原料配比、反应温度、反应时间、催化剂用量和带水剂用量对反应的影响,结果表明,当n(乙二醇)∶n(丙烯酸)=1.0∶2.2、反应温度为（120～125） ℃、反应时间60 min、催化剂用量为酸醇总物质的量的2.00%和带水剂甲苯用量20 mL的条件下, 酯化率达90.9%。     

离子液体中间体1-丁基-3-甲基咪唑溴盐的合成

以N-甲基咪唑和1-溴代正定烷为原料合成1-丁基-3-甲基咪唑溴盐[Bmim]Br,研究了反应时间、反应温度、及N-甲基咪唑与1-溴代正丁烷的摩尔比(原料比)和溶剂对[Bmim]Br收率的影响,产物结构经过1H NMR及FT-IR确认.实验结果表明,反应温度在60℃,反应时间为24h,N-甲基咪唑与1-溴代正丁烷的摩尔比(原料比)为1:1.2时,收率为93.13%.     

在Br(o)nsted酸性功能化离子液体中室温无溶剂合成长链脂肪酸甲酯

该文以N-甲基咪唑、苄基氯、硫酸、氯磺酸为原料,经季铵化、离子交换、磺化3步反应合成了磺酸型Br(o)nsted 酸性离子液体:1-(4-磺酸基苄基)-3-甲基-咪唑硫酸氢根盐,通过FTIR、1HNMR对其结构进行了确证.以其作为反应介质与催化剂,考察了C4～C16的直链脂肪酸与甲醇的Fischer酯化反应,确定了最佳反应条件:n(酸):n(醇):n(离子液体)=1:1:0.1,反应温度25 ℃、反应时间3～4.5 h,产率84%～98%,产物气相色谱纯度≥96%.该法无需加热、分水,产物分离简便,离子液体经真空除水后可重复使用,循环使用3次,催化活性保持不变.     

采用质子酸离子液体反应萃取精馏制备醋酸甲酯

以醋酸、甲醇为原料,以质子酸离子液体为催化剂和萃取剂,采用反应萃取精馏法制备了醋酸甲酯。考察了质子酸离子液体和配料比、回流比及反应时间对反应萃取精馏的影响。实验结果表明,质子酸离子液体是制备醋酸甲酯的良好催化剂和萃取剂,能消除醋酸甲酯与水或甲醇的共沸点,提高醋酸甲酯的纯度和收率;在3种质子酸离子液体[Hmim]CF3COO,[Hmim]BF4,[Hmim]HSO4中,[Hmim]HSO4(Hmim为N-甲基咪唑)的催化活性最高。反应萃取精馏的最佳工艺条件是:m(HOAc)∶m(CH3OH)∶m([Hmim]HSO4)=100∶50∶1,回流比2.5,反应时间30min。在此条件下,醋酸甲酯的纯度可达99.84%,收率可达98.65%。采用闪蒸的方法可回收醋酸、甲醇及质子酸离子液体,质子酸离子液体可重复使用8次。     

Doping manganese into CsPb(Cl/Br)3 quantum dots glasses: Dual-color emission and super thermal stability

CsPbX₃ (X = Cl, Br, I) perovskite quantum dots (QDs) represent bright and tunable photoluminescence, it is regrettable that the air instability and poor water resistant properties prevent their application in optoelectronic devices. At the same time, the toxicity of lead is also a major factor restricting its development. As a consequence, we demonstrate the partial replacement of Pb with Mn through conventional melt-quenching and heat-treatment method preparation of Mn-doped CsPb(Cl/Br)₃ QD glass. Mn-doped CsPb(Cl/Br)₃ QD glass exhibits high luminescent intensity like QDs. It is important that Mn-doped CsPb(Cl/Br)₃ QD glass with Dual-Color maintained the same lattice structure like Mn-doped CsPb(Cl/Br)₃ QDs, and highly homogeneous spectral characteristics of Mn luminescence. The intensity and position of this Mn-related emission are also tunable by altering the experimental parameters, such as the Pb-to-Mn feed ratio, annealing temperature. More importantly, the as-prepared orange Mn-doped CsPb(Cl/Br)₃ QD glass was employed to fabricate white LEDs combined with a commercial Ce³⁺:Y₃Al₅O₁₂ phosphor-in-glass (Ce-PiG) on top of a InGaN blue chip. And the constructed WLEDs generate a warm white with an optimal luminous efficacy (LE) of 67.00 lm/W, a high CRI of 81.4, and a low CCT of 4902 K.     

Synthesis of “walnut-like” BiOCl/Br solid solution photocatalyst by electrostatic self-assembly method

In this paper, under the control strategy of surface charge of BiOCl photocatalyst and the electrostatic adsorption of anions and cations in potassium bromide (KBr) and polyvinylpyrrolidone (PVP), the self-assembly of “walnut-like” BiOCl/Br solid solution nanophotocatalyst at a lower temperature water bath was proposed for the first time. X-ray diffraction (XRD), Raman, scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), energy-dispersive system (EDS), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET), UV-Vis, photoluminescence spectroscopy (PL) and Mott-Schottky curve, transient photocurrent densities, and electrochemical impedance spectroscopy (EIS) were used to analyze the properties of materials, including its morphology, element distribution and chemical states, specific surface area, electrochemical property, and photogenic charge transfer. Based on the degradation performance of RhB dye wastewater and phenol in visible and ultraviolet light, and the band structure of BiOCl/Br solid solution, the reason for the improved photocatalytic activity was deeply discussed, and the possible degradation mechanism was also put forward. The above results show that Br⁻ can be inserted into the crystal lattice of BiOCl under the effect of electrostatic adsorption to form solid solution by the interaction between atomic orbitals, which not only reduces the bandgap width but also improves the separation and mobility of photogenic electrons and holes, causing the absorbed light to shift red to the visible region. In addition, when the n_Br⁻/n_Cl⁻ = 0.67, “walnut-like” BiOCl/Br solid solution was formed, and this kind of special core-shell structure not only can increase the specific surface area, increase the number of active sites, but also can make the light reflect and refract many times in the cavity and further increase the utilization rate of light energy, and then the best photocatalytic activity was achieved. This study provides an new method to enhance the photocatalytic performance of BiOCl and be conducive to the development of modern material science.     

Negative thermal quenching CsPbBr3 glass-ceramic based on intrinsic radiation and vacancy defect co-induced dual-emission

Halide perovskite glass-ceramic has recently moved into the center of the attention of perovskite research due to their potential for temperature sensing. However, quantum dots glass-ceramic with excellent luminescence performance still needs to be combined with rare-earth (RE) ions to accurately measure temperature. In this work, a novel non-RE doped dual-emission (460 nm and 512 nm) CsPbBr₃ quantum dots was obtained in telluride glass via the friction crystallization method, where 512 nm was derived from intrinsic luminescence of quantum dots, and 460 nm was originated from thermally induced bromine vacancy, which can be used for temperature sensing. Fluorescence intensity ratio results indicate that the relative sensitivity of dual-emission could reach 5.6 % K^?1 at 323 K. The discovery of non-RE doped CsPbBr₃ QDs glass-ceramic with negative thermal quenching uncovers a new optional sensing glass material that surpass traditional RE-doped QDs glass by their tunability and sensitivity.     

Defect passivation strategy for inorganic CsPbI2Br perovskite solar cell with a high-efficiency of 16.77％

All-inorganic halide perovskite solar cells(PSCs)have acquired great progress,especially CsPbI2Br.However,their photoelectric conversion efficiency(PCE)remains far below the theoretical predictions.Non-radiative recombination is one of the important issues affecting the photoelectric performance of the PSCs,and the defective lead ions derived from the evaporation of halide ions in the inorganic per-ovskite are the principal non-radiative recombination centers.Herein,the non-radiative recombination is effectively suppressed by introducing the N-methyl-2-pyrrolidone(NMP)as a Lewis base molecule to passivate the defective lead ions.Therefore,by adjusting the dosage of NMP,the smooth and pinhole-free CsPbI2Br perovskite film is obtained and the optimized device exhibits a champion PCE of 16.77％with an excellent fill factor(FF)of 0.80.This work proves the effectiveness of passivation using Lewis base molecules to prevent non-radiative recombination defects in inorganic perovskite.