Tetrabutylammonium Bromide Functionalized Ti3C2Tx MXene as Versatile Cathode Buffer Layer for Efficient and Stable Inverted Perovskite Solar Cells

2D Ti₃C₂T_x MXene, possessing facile preparation, high electrical conductivity, flexibility, and solution processability, shows good application potential for enhancing device performance of perovskite solar cells (PVSCs). In this study, tetrabutylammonium bromide functionalized Ti₃C₂T_x (TBAB-Ti₃C₂T_x) is developed as cathode buffer layer (CBL) to regulate the PCBM/Ag cathode interfacial property for the first time. By virtue of the charge transfer from TBAB to Ti₃C₂T_x demonstrated by electron paramagnetic resonance and density functional theory, the TBAB-Ti₃C₂T_x CBL with high electrical conductivity exhibits significantly reduced work function of 3.9 eV, which enables optimization of energy level alignment and enhancement of charge extraction. Moreover, the TBAB-Ti₃C₂T_x CBL can effectively inhibit the migration of iodine ions from perovskite layer to Ag cathode, which synergistically suppresses defect states and reduce charge recombination. Consequently, utilizing MAPbI₃ perovskite without post-treatment, the TBAB-Ti₃C₂T_x based device exhibits a dramatically improved power conversion efficiency of 21.65% with significantly improved operational stability, which is one of the best efficiencies reported for the devices based on MAPbI₃/PCBM with different CBLs. These results indicate that TBAB-Ti₃C₂T_x shall be a promising CBL for high-performance inverted PVSCs and inspire the further applications of quaternary ammonium functionalized MXenes in PVSCs.     

The electroreduction of alkyl iodides and polyiodides: The kinetic model of EC(C)E and ECE-EC(C)E mechanisms with included transfer coefficient variability

The cyclic voltammetry electroreduction of seven alkyl iodides was investigated in 0.3 M TBAP/DMF on glassy carbon electrode. The influence of carbon chain length and the number of iodine atoms in the molecule was examined. The two-electron reductive cleavage with iodine elimination was numerically resolved into one-electron consecutive steps. The mechanism of the process was discussed applying the mathematical EC(C)E and ECE-EC(C)E kinetic models with included transfer coefficient variability for one stage electroreduction of RI and two stage electroreduction of RI₂, respectively. For electroreduction of diiodomethane the discrimination of elementary alpha parameter between two reduction stages was determined.     

哈格曼乙酯与硝基乙烷在不同碱催化下的迈克尔加成反应

研究了在不同有机碱催化下,哈格曼乙酯和硝基乙烷经迈克尔加成合成3 甲基 3 (1′ 硝基乙基) 4 乙氧甲酰环己酮的反应。结果表明,氟化四丁基铵的催化效果最好,且当n(氟化四丁基铵)∶n(哈格曼乙酯)=1∶2时,合成产物3 甲基 3 (1′ 硝基乙基) 4 乙氧甲酰环己酮的收率达到最高值56%。     

香料乙酸苄酯合成工艺研究

用氯化四正丁基铵作为相转移催化剂,对缩合法合成乙酸苄酯工艺进行改进。试验研究了反应物配比、催化剂用量及反应温度、反应时间等因素对缩合反应的影响。该法具有反应温度低、速度高等优点,收率可达９６％以上。尤其重要的是,新工艺不必在无水条件下进行,简化了合成工艺,又能使产品质量稳定。     

四丁基溴化铵催化合成环氧大豆油

在无溶剂无羧酸条件下,以四丁基溴化铵为相转移催化剂,用65%的叔丁基过氧化氢(TBHP)为氧源直接合成环氧大豆油。考察了反应温度、反应时间、催化剂用量及TBHP与碳碳双键摩尔比对环氧化反应的影响,通过红外光谱对催化环氧化的机理进行了初步探究。结果表明:在反应温度65℃、反应时间3 h、催化剂用量3.0 g(10.0 g大豆油)、TBHP与碳碳双键摩尔比1.5∶1条件下,催化环氧化效果最好,环氧值、转化率和选择性分别达到3.5%、53.9%和77.5%。此方法操作简单,催化剂价格低,简化了工艺流程,降低了工艺成本,同时克服了传统方法使用羧酸和溶剂等造成的弊端。     

四丁基氯化铵半笼型水合物的相平衡模型

本文在范德瓦尔?普朗特理论的基础上,考虑了四丁基氯化铵（TBAC）水合物的结构特征,建立了TBAC半笼型水合物相平衡模型。模型确定了水在空水合物晶格的蒸汽压及兰格缪尔常数与TBAC浓度的关系,引用e-NRTL模型和PR气体状态方程分别计算液相组分活度系数和客体分子气相逸度。同时,本文在280.1 K ~ 293.6 K温度范围和0.337 MPa ~ 7.017 MPa压力范围内预测了TBAC质量浓度范围为4.34% ~ 34%的溶液体系下TBAC + CH₄、TBAC + CO₂半笼型水合物的相平衡条件,预测压力与实验数据的平均绝对偏差分别为3.2637% 和9.2258%。预测结果与实验数据吻合较好。     

Electron transfer of peroxidase assemblies at tailored nanocarbon electrodes

In bioelectrochemistry, the catalytic function of redox enzymes depends largely upon the nature of the working electrode material. One major example of this phenomenon is the improvement of biogenic analyte detection at graphitic carbon with increased edge plane character in the graphene lattice. In our laboratories, we have found that the edge plane character of carbon nanotubes (CNTs) prepared using chemical vapor deposition (CVD) can be tuned via selective doping with nitrogen, termed N-CNTs. In this report, we extend these studies to investigate the influence of N-doping of nanocarbons on the electron transfer of horseradish peroxidase (HRP) using spectrophotometric enzyme activity assays and electrochemical measurements. Our findings demonstrate that HRP adsorption at N-CNTs increases by a factor of two relative to that of nondoped CNTs, with surface coverages, Γ_m, of 75 ± 4 and 33 ± 5 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) U/mg, respectively. Surprisingly, however, only ∼40% of the HRP adsorbed at N-CNTs is electroactive, as assessed by voltammetry of the HRP Fe^2+/3+ redox response. By contrast, HRP adsorbed at nondoped CNTs is nearly 100% electroactive, suggesting that the nature of the HRP adsorption (e.g., electrostatic, van der Waals) and geometric factors of heme orientation affect the biocatalytic performance. We also describe studies that utilize the properties of both nondoped CNTs and N-CNTs with adsorbed HRP for unmediated, quantitative H₂O₂ sensing.     

a-SiW11Mn／四丁基溴化铵电荷转移配合物的合成及热分解动力学研究

文章合成了Keggin结构锰取代杂多钨硅酸盐四丁基溴化胺电荷转移配合物,用元素分析、UV、TG-DTG等方法对其进行了表征。结果显示该化合物仍保持杂多阴离子的Keggin结构的基本特征。用TG-DTG的方法研究了R-（TBA）4H2[SiWIiMn（H20）O39]·14H2O的热解机理和动力学,采用了Doyle方程和Coats-Redfem方程对非等温动力学数据进行了分析,得到了热分解反应的机理函数,动力学参数以及分解反应的活化能E和InA。     

Synthesis,characterization and use of polymer‐supported phase transfer catalyst in organic reactions

A polymer‐supported (PS) phase transfer catalyst, polyethylene‐g‐quaternary ammonium salt (PE‐g‐Q_N⁺), is prepared through a three‐step graft copolymerization of maleic anhydride (MAn) onto polyethylene (PE) by photochemical method using 1% benzophenone (Bz) as photosensitizer. Post grafted acid hydrolysis of polyethylene‐g‐maleic anhydride (PE‐g‐MAn) results in the preparation of PE‐g‐succinic acid which on further treatment with tetrabutylammonium bromide (TBAB) under basic conditions in tetrahydrofuran (THF) gives PE‐g‐Q_N⁺. Optimum conditions pertaining to maximum percentage of grafting have been evaluated as a function of concentration of maleic anhydride, amount of photosensitizer, and time of reaction. Maximum percentage of grafting (25%) was obtained using 3.57 mol of MAn and 0.5 mL of 1% Bz in 120 min. The PE and graft copolymers, PE‐g‐MAn, and PE‐g‐Q_N⁺ were characterized by FTIR Spectroscopy and thermogravimetric analysis (TGA). The ionic nature of quaternary ammonium salt, PE‐g‐Q_N⁺ has also been confirmed by conductance measurements. PE‐g‐Q_N⁺ reagent have been used successfully for polymerization, amidation, and esterification reactions. The products obtained were characterized by FTIR and H¹NMR spectral methods. The reagent was reused for the further reactions and it was observed that the polymeric reagent polymerize, amidate, and esterificate the compounds successfully but with little lower product yield. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011