光催化与现代测试技术应用于物理化学实验的探索——以锑掺杂氧化铋的制备及光催化性能测试为例

以一个掺杂型复合催化剂的制备与催化性能测试为实例,尝试了将光催化和现代测试技术应用于物理化学实验教学。采用溶剂热法合成锑掺杂氧化铋纳米材料,并通过X射线粉末衍射和扫描电子显微镜对其成分和形貌进行表征。选取罗丹明B作为模拟有机污染物,对可见光条件下锑掺杂前后氧化铋纳米材料光催化性能进行评价。结合材料光学性质和光电性质分析探讨锑掺杂提高氧化铋纳米材料光催化性能的机制。通过开设该实验,可让学生获取化学学科的前沿知识,了解光催化反应以及各种现代测试技术的基本原理,掌握新的实验操作技能和数据处理方法,加深对物理化学基础知识的理解,对提高学生的综合实验能力,培养创新型、复合型人才具有重要意义。     

钼酸铋纳米片的制备以及光催化性能测试*

以硝酸铋与磷钼酸为原料,通过水热反应制备高催化活性光催化剂,应用X射线衍射和扫描电子显微镜进行材料表征,通过以氙灯为光源研究材料对四环素的表面光催化降解的特性。本实验涉及无机纳米材料的水热合成、结构表征以及有机类污染物光催化降解应用,将无机化学、物理化学、有机化学和分析化学的理论内容、实验方法与科学研究前沿相结合,能够全方位提升本科大学生的综合实验技能及科学研究水平。     

BiOBr的制备及其光催化性能的研究

以氧化铋为原料,采用水解法合成了溴氧化铋光催化剂,采用X射线衍射仪对溴氧化铋晶体进行表征,研究了溴氧化铋晶体降解罗丹明B溶液的光催化性能。实验结果表明,在反应温度为40℃、反应时间为90 min合成的Bi OBr光催化性能最好,具有较强的光催化活性,其催化活性优于Bi OCl催化剂,其催化降解罗丹明B反应表现为假一级动力学。     

碳酸氧铋光催化剂的合成与光催化降解有机染料

大学化学综合实验——碳酸氧铋光催化剂的合成与光催化降解有机染料。学生可以熟悉光催化材料合成的方法、材料的结构及形貌的表征手段,以及了解并熟悉纳米材料的光催化原理和光催化实验过程。在掌握基础理论和基本实验技能的同时,培养学生独立思考问题、分析问题和解决问题的能力,尤其是培养他们综合运用知识的能力。     

水热pH值对溴氧化铋组成、形貌及光催化性能的影响

通过调节pH值一步水热法制备溴氧化铋光催化剂,并利用X射线衍射（XRD）、扫描电镜（SEM）、紫外-可见漫反射光谱（UV-vis DRS）和固体荧光光谱（PL）等方法对其进行表征。在可见光（γ>420 nm）照射下,通过对水溶液中罗丹明B,甲基橙和苯酚的降解效果来评价溴氧化铋的光催化活性。结果表明,由于B9提高了对可见光的吸收以及电子-空穴对的分离效率,B9具有最好的光催化活性,同时探索水热pH值对制备溴氧化铋的形貌和组成的影响,并说明了不同水热pH值下溴氧化铋的合成过程。     

AuNPs@POMs/rGO复合材料的制备及光催化性能

以Keggin型多金属氧酸盐(多酸,POMs)为光催化还原剂、稳定剂和包覆剂,在光照下一步合成AuNPs@POMs/rGO复合纳米材料。采用透射电镜(TEM)、X射线衍射(XRD)和紫外-可见吸收光谱(UV-vis)等对所制得的材料进行了结构表征和性能测试。以光催化降解甲基橙为模型反应研究了AuNPs@POMs/rGO纳米复合材料的光催化活性。透射电子镜结果显示Au纳米微粒均匀的负载在rGO薄层上,无聚集和团聚现象。实验探究了pH、温度、催化剂投放量以及甲基橙初始浓度对光催化降解过程的影响。光催化降解结果表明:当溶液处于室温,pH=8.0,催化剂投放量为0.15 g·L~(-1),甲基橙溶液初始浓度为25.0 mg·L~(-1)时,效果达到最佳,降解率为94.5%。     

水热pH值对溴氧化铋组成、形貌及光催化性能的影响（英文）

通过调节pH值一步水热法制备溴氧化铋光催化剂,并利用X射线衍射(XRD)、扫描电镜(SEM)、紫外-可见漫反射光谱(UV-vis DRS)和固体荧光光谱(PL)等方法对其进行表征。在可见光(λ 420 nm)照射下,通过对水溶液中罗丹明B,甲基橙和苯酚的降解效果来评价溴氧化铋的光催化活性。结果表明,由于B9提高了对可见光的吸收以及电子-空穴对的分离效率,B9具有最好的光催化活性,同时探索水热pH值对制备溴氧化铋的形貌和组成的影响,并说明了不同水热pH值下溴氧化铋的合成过程。     

石墨相氮化碳的模板法制备、表征及光催化性能测试综合化学实验

采用简单原料（单氰胺、硅溶胶）利用模板法制备石墨相氮化碳,并对所得产物进行结构表征与形貌分析。采用光催化降解亚甲基蓝实验评价石墨相氮化碳的可见光催化性能,得到降解反应动力学方程与降解速率常数。通过实验,可使学生熟悉纳米材料可控制备中常用的模板法,对产物的测试与表征有利于加深学生对光催化材料结构与性能的了解。实验涉及多个学科领域,有利于拓宽学生知识面,培养学生科研创新能力。     

TiO_2纳米粉体的掺杂改性及光催化性能研究——伯苓班无机综合实验

南开大学化学学院伯苓班本科生的无机综合实验课程中,开展"TiO_2纳米粉体的掺杂改性及光催化性能研究"实验,学生自主选择掺杂元素及含量,以溶胶-凝胶方法制备不同金属及非金属掺杂的TiO_2纳米粉体,采用扫描电镜、透射电镜、X射线衍射、紫外漫反射等手段表征所得材料,以甲基橙溶液模拟有机废水,研究催化剂在紫外光下的催化降解活性,选取性能最佳催化剂,测试其在模拟日光下的光解水性能。通过开展贴近科研前沿的实验内容,对伯苓班学生进行系统的科研训练,培养他们的综合科研能力。     

氮掺杂多孔石墨烯对硝基和偶氮化合物的催化还原性能——化学相关专业综合实验的设计与实践

针对溶有常见含硝基和偶氮化合物废水处理的问题，设计了无金属碳基催化剂制备及其对此类化合物催化还原的综合实验。实验以氧化石墨烯为原料，经水热法合成碳基催化剂氮掺杂多孔石墨烯或氮掺杂石墨烯，通过扫描电子显微镜、透射电子显微镜、比表面分析仪、X射线光电子能谱等对其结构、形貌和元素组成等进行表征，并研究其对硼氢化钠还原硝基和偶氮化合物的性能。该实验涉及碳基催化剂制备、表征和废水处理等多个实验环节，涵盖了物理化学、材料化学和环境化学等多个学科领域。通过该实验可以培养学生的科研思维，提高学生的科研动手能力和用化学知识解决实际问题的能力。     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

恶臭嗅辨实验室建设探讨

针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。     

氯氧化镁生成热的研究

用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。     

Summary of development of the theory of stability of colloids and thin films

In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.     

Study of hydration of two cements of different strengths

Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M_o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700^oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.     

解决能源问题的新途径--光解水制氢的研究

面对日益枯竭的能源危机,氢能是一种洁净、最有前景的替代能源。目前在各种制氢的方法中光催化分解水制氢的研究最多,光解水过程中催化剂最关键,本文对利用太阳能光解水的途径、提高光催化反应效率以及光催化剂的开发研究进行了综述。