【大学化学】doi: 10.3866/PKU.DXHX202311027
在化工热力学实验教学中,通过设置进阶训练思考题,激励学生进行探索与实践。以第二维里系数的测定实验为例,倡导学生独立思考与构建高阶维里系数的方法,引导其分析比较国内外学者处理问题的策略与方法,而后辅导其通过双向检验证明所做实验数据的准确性、验证所构建方法的合理性、分析所得结果的有效性,最后指导学生理清数据处理方法的发展脉络,对其所构建的方法进行准确定位与评价。本教学实践通过强化实验教学项目的设计性与综合性,探索提升实验类课程高阶性的途径,践行“两性一度”的要求。
【大学化学】doi: 10.12461/PKU.DXHX202411076
在化学反应动力学研究中,动力学同位素效应(KIE)为深入理解化学反应路径和机制提供了关键信息。除了广泛应用的氢/氘同位素效应外, 碳原子以及质量更大一些原子的同位素效应也日益受到关注。值得一提的是, Singleton于1995年提出了一种基于核磁共振(NMR)技术的高精度KIE (12C/13C)测量方法,为该领域带来了重要突破。该方法无需对化合物进行昂贵且复杂的同位素标记操作,利用13C的自然丰度的样品结合高分辨率NMR实验,能够直接测量12C和13C之间的KIE数值,且具有极高的精度。本文将详细介绍这一方法的理论基础、实验步骤以及应用实例,探讨其在化学反应机理和动力学研究中的重要意义与优势。
【大学化学】doi: 10.12461/PKU.DXHX202504055
电动势法测定电解质溶液的平均活度系数是一个经典的物理化学实验。然而,实验过程中,需要持续向溶液中通入氢气以形成氢电极,导致存在氢气泄漏引发爆炸的安全隐患。为解决该问题,本实验提出了一种改进方法:利用电解法制备氢电极来替代原有持续通入氢气的方法。改进后,测量过程中无需持续通入氢气,实验不再需要氢气钢瓶或氢气发生器,从根本上杜绝氢气泄漏和爆炸的风险,确保了实验的安全性。另外,本实验设计不但有助于学生理解物理化学理论课讲授的更多知识点,而且训练了学生掌握电解法制备氢电极的新技能。
【无机化学学报】doi: 10.11862/CJIC.20250373
Developing high-performance electrocatalysts for the alkaline hydrogen oxidation reaction (HOR) is essential for advancing alkaline hydrogen fuel cells. Here, we report the synthesis of ruthenium (Ru) catalysts with tuned crystallinity and oxidation degree. By combining template-assisted synthesis with controlled thermal treatment, amorphous, partially crystalline, highly crystalline, and partially oxidized Ru products were successfully obtained. Catalysts with moderate crystallinity and partial oxidation exhibit enhanced catalytic activity toward the alkaline hydrogen oxidation reaction. The optimized Ru-RuO2 catalyst achieved a mass activity of 81.66 mA·mgRu-1, which was 2.27 times that of commercial Pt/C under identical conditions. The improved activity is attributed to the synergistic effect of moderate crystallinity and partial oxidation, which favors a favorable Tafel-Volmer reaction pathway.
【无机化学学报】doi: 10.11862/CJIC.20230310
A unique 3D luminescent metal-organic framework, namely [Cd(L)(H2O)0.5]·DMF·2.5H2O (1), where H2L=3-(tetrazol-5-yl)triazole, has been successfully prepared and characterized. The framework has demonstrated excellent luminescence properties and structural stability in the water system. Notably, the luminescence intensity of 1 was significantly quenched by Cr(Ⅵ) (1 mL of Cr2O72- or 150 μL of CrO42-, 1 mmol·L-1), leading to the formation of an "on-off" luminescence silencing system (Cr2O72-@1), which was capable of accurately detecting Cr(Ⅵ) in the water system. The primary mechanism responsible for luminescence quenching was the Forster resonance energy transfer (FRET) process. Additionally, by removing the involvement of the FRET process, the luminescence intensity of the Cr2O72-@1 system could be restored, allowing for the highly selective and sensitive detection of ascorbic acid (AA) in water systems. Moreover, it has been demonstrated that 1 can successfully detect AA in vitamin C tablets, yielding recovery rates ranging from 98.20% to 103.33% and relative standard deviations (RSDs) ranging from 1.78% to 3.42%. Based on the findings of this experiment, a luminescent "IMPLICATION" molecular logic gate has been constructed utilizing AA and Cr(Ⅵ) as the chemical inputs, respectively.
【物理化学学报】doi: 10.3866/PKU.WHXB202308024
由于电催化剂中的非晶区和结晶区具有不同的物理化学性质,因此非晶化/结晶化工程成为提高电解水催化动力学的重要策略。然而,在微观环境中有效地调控催化剂的结晶度仍然是一个严峻的挑战。本文介绍了一种可调节结晶度的新型CrS/CoS2异质结构,该异质结对氢气析出反应(HER)和氧气析出反应(OER)都具有高效的催化活性。Cr―S―Co键的重新分配引起的d带中心移动有助于调节中间体H*和OOH*在催化剂表面的吸附能力,从而优化HER和OER的决速步骤。在最佳条件下,非晶态CrS和高度结晶的CoS2异质结(A-CrS/HC-CoS2)在HER和OER均表现出优异的催化活性,分别为90.6 mV (10 mA∙cm−2,HER)和370.5 mV (50 mA∙cm−2,OER)。非晶/高晶结构有利于A-CrS/HC-CoS2在水电解过程中的结构和成分演变,因此具有出色的稳定性。作为甲醇辅助节能制氢装置中的双功能催化剂,A-CrS/HC-CoS2仅需1.51 Ⅴ的低槽电压即可达到10 mA∙cm−2的电流密度,证明其是理想的金属基催化剂的候选材料。本研究为双功能过渡金属化合物电催化剂在非晶态/晶态异质结构中通过结晶度调控来提高催化活性和稳定性提供了重要启示。
【无机化学学报】doi: 10.11862/CJIC.20250190
Herein, a luminescent europium-based metal-organic framework (Eu-MOF, [Eu3(L)(HL)(NO3)2(DMF)2]·4DMF·5H2O, H4L=5,5′-(pyrazine-2,6-diyl)diisophthalic acid, DMF=N,N-dimethylformamide) was developed for the dual-functional detection of environmental pollutants. This fluorescence-quenching-based sensor exhibited exceptional sensitivity for both 2,4,6-trinitrophenol (TNP) and tetracycline (TC), achieving remarkably low detection limits of 1.96×10-6 and 1.71×10-7 mol·L-1, respectively. Notably, the system exhibited 99% fluorescence quenching efficiency for TC, indicating ultra-efficient analyte recognition. The detection performance surpasses most reported luminescent MOF sensors, attributed to synergistic mechanisms of fluorescence resonance energy transfer (FRET) and photoinduced electron transfer (PET).
【大学化学】doi: 10.12461/PKU.DXHX202510089
在“四新”建设背景下,针对化学课程与非化类专业存在的基础与专业脱节、理论与实践割裂、创新与应用薄弱的关键问题,吉林大学化学学院以非化类多学科专业差异化需求为中心,从教学管理、教学实施方法和教师队伍建设三维度着手,深化教学内容与方法、学科与专业素养、实践与创新能力、课内与课外协同和多元评价体系五方面融合,系统构建并实践“一中心、三维度、五融合”的“化学+四新”融合式课程体系,实现化学通识与专业培养的深度衔接。经实践检验,该模式为非化类专业的化学教学提供可操作的“四新”融合方案,使化学基础类课程从“通识配角”走向“四新枢纽”,并为适配多专业背景下的基础课改革提供可复制、可推广范式。
