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91.
为了对苦卤结晶析出的Na(Cl,Br)固溶体中氯化钠组分和溴化钠组分进行分离,测定了NaCl–NaBr–CH3OH三元体系在273及323 K温度时的溶解度数据,根据测得的液相点和湿渣相点确定了对应的固相点,由此绘制出了两个温度下的相图。结果显示,273及323 K温度下该三元体系的相图特征相似,均只有一个共饱点、两条饱和溶解度曲线,对应的固相结晶区有三个:NaCl纯盐结晶区、NaCl和Na(Cl,Br)固溶体共结晶区、Na(Cl,Br)固溶体结晶区。NaBr在无水甲醇中溶解度的增大导致NaCl溶解度大幅减小,说明NaBr对NaCl产生了较强的盐析效应,273 K时两种溶质在甲醇中的溶解度均比323 K时的溶解度大。依据273和323 K的NaCl–NaBr–CH3OH体系相图及298 K的NaCl–NaBr–H2O体系相图设计了分离Na(Cl,Br)固溶体中氯化钠和溴化钠的工艺。 相似文献
92.
Jun Di Jiexiang Xia Matthew F. Chisholm Jun Zhong Chao Chen Xingzhong Cao Fan Dong Zhen Chi Hailong Chen Yu‐Xiang Weng Jun Xiong Shi‐Ze Yang Huaming Li Zheng Liu Sheng Dai 《Advanced materials (Deerfield Beach, Fla.)》2019,31(28)
Solar photocatalysis is a potential solution to satisfying energy demand and its resulting environmental impact. However, the low electron–hole separation efficiency in semiconductors has slowed the development of this technology. The effect of defects on electron–hole separation is not always clear. A model atomically thin structure of single‐unit‐cell Bi3O4Br nanosheets with surface defects is proposed to boost photocatalytic efficiency by simultaneously promoting bulk‐ and surface‐charge separation. Defect‐rich single‐unit‐cell Bi3O4Br displays 4.9 and 30.9 times enhanced photocatalytic hydrogen evolution and nitrogen fixation activity, respectively, than bulk Bi3O4Br. After the preparation of single‐unit‐cell structure, the bismuth defects are controlled to tune the oxygen defects. Benefiting from the unique single‐unit‐cell architecture and defects, the local atomic arrangement and electronic structure are tuned so as to greatly increase the charge separation efficiency and subsequently boost photocatalytic activity. This strategy provides an accessible pathway for next‐generation photocatalysts. 相似文献
93.
有机-无机杂化钙钛矿材料中易挥发的有机成分(MA+,FA+)用高耐热性无机金属铯离子(Cs+)取代,用其制备的太阳能电池具有优异的热稳定性。自2016年以来,以CsPbI2Br材料作为光活性层的无机钙钛矿太阳能电池(IPSCs)的光电转换效率(PCE)从9.84%提高到18.06%,但是IPSCs的稳定性问题仍然制约其商业化。本文总结和分析了影响CsPbI2Br IPSCs稳定性的因素,从制备工艺、离子掺杂、界面优化等方面评述了近年来IPSCs稳定性的研究进展,并展望了CsPbI2Br IPSCs的研究趋势和发展方向。 相似文献
94.
二乙二醇甲基丁基醚的合成研究 总被引:1,自引:0,他引:1
在氮气保护下,以二乙二醇单甲醚(C5H12O3,DEGME)和正溴丁烷为(n-C4H9Br)原料,氢氧化钠为催化剂,苯为带水剂,通过Williamson反应合成了二乙二醇甲基丁基醚(DGBME);用正交实验法对合成条件进行了优化,气相色谱法分析了产品中DGBME的含量,FT-IR和1HNMR法表征了产物结构。结果表明,适宜的反应条件为:反应温度80℃,反应时间4 h,n(n-C4H9Br)∶n(DEGME)=1.06∶1,n(NaOH)∶n(DEGME)=1.5∶1.0;在此条件下,DGBME的收率可达92%以上。 相似文献
95.
Sukjeong Choi Ki-Sub Kim Jong-Ho Cha Huen Lee Jae Seung Oh Byoung-Bae Lee 《Korean Journal of Chemical Engineering》2006,23(5):795-799
A series of ionic liquids based on morpholinium cations were prepared. N-alkyl-N-methylmorpholinium bromide, N-alkyl-N-methylmorpholinium
tetrafluoroborate, N-alkyl-N-methylmorpholinium hexafluorophosphate and N-alkyl-N-methylmorpholinium bis(trifluoromethanesulfonyl)imide
were synthesized, and then thermal and electrochemical properties of prepared ionic liquids were measured. These morpholinium
salts were found to be thermally stable near 673 K and electrochemically stable up to 6 V at room temperature. In conclusion,
these new series of morpholinium based ILs might be potential candidates for electrolytes in batteries and other electrolytic
devices. 相似文献
96.
董文龙 《洛阳理工学院学报(自然科学版)》2011,(3):6-9
通过分子组装和晶体工程的方法,金属离子和有机阳离子在一定条件下可以得到具有高度规则的配位聚合物.将合成的新型有机阳离子BPHP· Br2与金属盐AgI进行分子组装,合成了结构新颖的有机-无机复合化合物[(Ap2I4)(BPHP)]n,通过单晶衍射仪收集了衍射数据,并解出了其晶体结构,该配合物形成了一维的链状结构,它在非... 相似文献
97.
A reliable ultrasound-assisted extraction (UAE) method combined with HPLC-UV for quantification of eight active alkaloids in fruits of Macleaya cordata (Willd) R. Br. was developed. The optimization conditions of UAE were obtained by using Box-Behnken design of response surface methodology. Chromatography was carried out using a Kromasil C18 column by gradient elution with 0.1% phosphoric acid aqueous solution for HPLC-UV. All calibration curves showed good linear correlation coefficients (R2>0.999 6) and recoveries (from 97.3% to 104.9%) were acceptable. l,l-diphenyl-2-picrylhydrazyl (DPPH) method was employed to test the antioxidant activity of the extract from the samples. The proposed method was successfully applied to quantifying eight components in nine samples of M.cordata, and significant variations of alkaloid contents and antioxidant activity of the samples from different habitats were demonstrated. It presents a powerful proof for the selection of the best sources to extract eight kinds of alkaloids. 相似文献
98.
HPLC-ICP-MS hyphenated techniques were developed for the elemental speciation analysis. Different species of I, Br and Hg were successfully separated and determined. The linier dynamic ranges, the detection limits were discussed. The compound independent calibration (CIC) phenomenon for HPLC-ICP-MS techniques were found and its good potential in applications were discussed as example. 相似文献
99.
Precursor Engineering for All‐Inorganic CsPbI2Br Perovskite Solar Cells with 14.78% Efficiency
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Guannan Yin Huan Zhao Hong Jiang Shihao Yuan Tianqi Niu Kui Zhao Zhike Liu Shengzhong Liu 《Advanced functional materials》2018,28(39)
The optoelectronic properties of perovskite films are closely related to the film quality, so depositing dense, uniform, and stable perovskite films is crucial for fabricating high‐performance perovskite solar cells (PSCs). CsPbI2Br perovskite, prized for its superb stability toward light soaking and thermal aging, has received a great deal of attention recently. However, the air instability and poor performance of CsPbI2Br PSCs are hindering its further progress. Here, an approach is reported for depositing high‐quality CsPbI2Br films via the Lewis base adducts PbI2(DMSO) and PbBr2(DMSO) as precursors to slow the crystallization of the perovskite film. This process produces CsPbI2Br films with large‐scale crystalline grains, flat surfaces, low defects, and long carrier lifetimes. More interestingly, PbI2(DMSO) and PbBr2(DMSO) adducts could significantly improve the stability of CsPbI2Br films in air. Using films prepared by this technique, a power conversion efficiency (PCE) of 14.78% is obtained in CsPbI2Br PSCs, which is the highest PCE value reported for CsPbI2Br‐based PSCs to date. In addition, the PSCs based on DMSO adducts show an extended operational lifetime in air. These excellent performances indicate that preparing high‐quality inorganic perovskite films by using DMSO adducts will be a potential method for improving the performance of other inorganic PSCs. 相似文献
100.
Quantum Dots: CsPbX3 Quantum Dots for Lighting and Displays: Room‐Temperature Synthesis,Photoluminescence Superiorities,Underlying Origins and White Light‐Emitting Diodes (Adv. Funct. Mater. 15/2016)
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Xiaoming Li Ye Wu Shengli Zhang Bo Cai Yu Gu Jizhong Song Haibo Zeng 《Advanced functional materials》2016,26(15):2584-2584