OPTICAL MATERIALS
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2019
·
IF 2.687
Jidong Deng,Jiao Xun,Rongxing He
All-inorganic cesium lead halide perovskite nanocrystals (NCs) are promising photoelectric materials for their high photoluminescence quantum yield (PLQY), narrow emission width and tunable optical band gap. Traditionally, the hot injection (HI) method has been utilized to prepare perovskite NCs. However, the HI method requires high temperature, protection under inert gas and other harsh synthetic conditions, which severely hinders large-scale production of these NCs. Herein, we directly synthesized CsPbBr 3 perovskite NCs by a modified LARP (ligand-assisted re-precipitation) approach, and then conducted a specific anion exchange reaction with inexpensive, readily available, non-toxic, and non-polluting KX (X = Cl, I) salts aqueous solution to obtain various compositions of CsPbX 3 perovskite NCs at room temperature (RT). The obtained RT-NCs have high PLQY and outstanding stability, and their photoluminescence can be precisely regulated across the whole visible region (419–670 nm). The use of inorganic salts for the ion exchange provides an efficient method for the design of various halogenated perovskite NCs and their large-scale synthesis at RT.
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ANALYTICAL CHEMISTRY
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2019
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IF 6.35
Xinfeng Zhang,Xiaoya Fan,Yanying Wang,Fengjie Lei,Lin Li,Juewen Liu,Peng Wu
Aggregation of plasmonic gold nanoparticles (AuNPs) has been widely used for label-free colorimetric sensing. Adding salt is a commonly used method to induce a color change, but salt-induced aggregation by charge screening is a slow kinetic process, making quantitative and reproducible measurement difficult. Herein, we explored an alternative method by charge neutralization using positively charged molecules, such as a DNA-staining dye, SYBR Green I (SG), for efficient and stable assembly of AuNPs. Even submicromolar SG effectively triggered the aggregation of AuNPs in less than 1 min, and the resulting intense blue color was stable for over 10 h. The charge neutralization effect of SG was confirmed with zeta potential measurements. Besides, pH-dependent aggregation of AuNPs by SG agreed well with the pKa of the nitrogen atoms responsible for the positive charges in the SG structure. Moreover, the charge neutralization effect was also observed from polycations such as polyamines. The SG-induced assembly of AuNPs was developed into a label-free colorimetric sensing platform. Benefiting from the intense blue color, this new sensing strategy allowed visual detection of as low as 0.1 nM DNA, 50-fold lower than that by salt. Such a charge neutralization strategy may inspire further thinking on fundamental colloidal science and its applications in analytical chemistry. This work itself significantly improved AuNP-based colorimetric sensors in terms of detection time, signal stability, and sensitivity.
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CHEMICAL ENGINEERING JOURNAL
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2019
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IF 8.355
Qian Ye,Hao Xu,Jing Zhang,Qingguo Wang,Peng Zhou,Yunqi Wang,Xue Huang,Xiaowei Huo,Chaorong Liu,Jinfeng Lu
This work presented a new strategy to activate peroxymonosulfate (PMS) by the addition of nano-zero-valent tungsten (nZVT) via accelerating the redox cycles of Cu(II)/Cu(I), which induce the consecutive generation of highly reactive oxygen species ultimately. The oxidation capacity of the nZVT/Cu(II)/PMS process and the detailed mechanisms of PMS activation were investigated with tetracycline (TC) as the targeted pollutant. Our results indicated that about 70% TC removal was obtained in the nZVT/Cu(II)/PMS system in 15 min with an initial pH of 4.6. In addition, hydroxyl radicals ( OH), sulfate radicals (SO 4 − ), and superoxide radicals ( O 2 − ) were identified as the reactive oxygen species (ROSs) attributed to rapid TC decomposition according to the quenching studies and EPR technology. The effective component that was responsible for PMS activation and ROSs generation was ascertained to be the resulting Cu(I), which derived from the direct reduction pathway driven by epigenetic low valence tungsten species and the indirect reduction pathway driven by active hydrogen atoms. Further, the presence of Cu(II) significantly accelerated the corrosion of the nZVT powders, leading to the accumulation of low valence tungsten species and the decrease in the mean diameter of the ZVT nanoparticles. There was no obvious change of the composition and structure between the original and residual nZVT powders, as evidenced by XPS and XRD analysis. The degradation process of TC included the cleavage of specific functional groups, the ring-opening reactions and the hydroxylation process. This study provided theoretical significance in applying zero-valent metals to activate PMS through a cupric/cuprous redox cycling mechanism.
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ACS Sensors
·
2019
·
IF 6.944
Liping Zhu,Jing Ye,Mengxia Yan,Qiuju Zhu,Shuang Wang,Jianshe Huang,Xiurong Yang
Measurement of cardiac troponin I in the blood is crucial for the early diagnosis of acute myocardial infarction. Herein, a novel and ultrasensitive electrochemiluminescence (ECL) immunosensor has been developed for determination of cardiac troponin I (cTnI) by using Au nanoclusters and hybridization chain reaction (HCR) signal amplification. In this ECL immunosensor, Au nanoclusters were dual-labeled at each end of hairpin DNA (H1 and H2) and acted as the luminophore. DNA initiator strands (T1) and secondary antibody (Ab2) were conjugated on Au nanoparticles (AuNPs) to obtain a smart probe (Ab2-AuNP-T1). In the presence of target cTnI, the sandwiched immunocomplex composed of cTnI, Ab1, and Ab2-AuNP-T1 was formed. Then the initiator strands T1 of Ab2-AuNP-T1 opened the hairpin DNA structures and triggered a cascade of hybridization events. Consequently, a large number of Au NCs were indirectly modified on the surface of the electrode, which could react with the coreactant (K2S2O8) and emit a strong ECL signal. Under the optimal conditions, the immunosensor exhibited a wide detection range for cTnI from 5 fg/mL to 50 ng/mL and a low detection limit of 1.01 fg/mL (S/N = 3). Because of the excellent specificity, stability, and reproducibility of the proposed ECL-HCR sensor, it has a great application prospect for cTnI detection in clinical diagnosis.
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Science China-Chemistry
·
2019
·Vol. 62
·期 6
·767-774
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IF 6.085
Li Erpeng,Li Wenqin,Li Linchang,Zhang Hao,Shen Chao,Wu Zihua,Zhang Weiwei,Xu Xiaojia,Tian He,Zhu Wei-Hong,Wu Yongzhen
The development of p-i-n structured perovskite solar cells (PSCs) requires more extensive explorations on seeking efficient, low cost and stable hole transporting materials (HTMs). Small molecular HTMs are superior to polymeric ones in terms of synthetic reproducibility as well as purity. However, thin films composed of small molecules are usually labile during the solution-based perovskite deposition. Herein, we propose a molecular engineering strategy of incorporating oligothiophene as conjugation bridge to develop robust oligomer HTMs for p-i-n type PSCs. Upon increasing the oligothiophene chain length from α-bithiophene to α-quaterthiophene and α-hexathiophene, their HOMO energy levels remain unchanged, but their solubility in common organic solvents decreased remarkably, thus greatly enhancing their tolerance to the perovskite deposition. The rational design of oligothiophene chain length can effectively tune their optoelectronic properties as well as thin film stability under polar solvent soaking. The best performance is achieved by an α-quaterthiophene based HTM (QT), showing a high efficiency of 17.69% with fill factor of 0.81, which are comparable to those of a commercially available benchmark polymer HTM (poly[bis (4-phenyl)(2,4-dimethylphenyl) amine], PTAA) based devices fabricated under the same conditions. Our developed oligomer system not only provides the definite molecular structures like small molecule-type HTMs, but also exhibits the excellent film-forming like polymer-type HTMs, thus achieving the well-balanced parameters among solvent tolerance, thin film conductivity, and interfacial charge transfer efficiency, especially building up a platform to develop low cost and reproducible efficient HTMs in p-i-n structured perovskite solar cells.
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COMBUSTION AND FLAME
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2019
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IF 4.12
Wei Li,Yan Zhang,Bowen Mei,Yuyang Li,Chuangchuang Cao,Jiabiao Zou,Jiuzhong Yang,Zhanjun Cheng
Flow reactor pyrolysis and laminar flame propagation are investigated for n -propanol and i -propanol, which are the smallest alcohol fuels with isomeric structures. Pyrolysis products of propanol isomers at 0.04–1 atm are detected using the synchrotron vacuum ultraviolet photoionization mass spectrometry (SVUV-PIMS). Experimental observations demonstrate ethylene and propene are respective dominant hydrocarbon products in the n -propanol and i -propanol pyrolysis, while the most abundant oxygenated products are formaldehyde, acetaldehyde and ethenol in the n -propanol pyrolysis and acetone and acetaldehyde in the i -propanol pyrolysis. Higher concentrations of aromatic and oxygenated pollutants are observed in the i -propanol pyrolysis. The laminar burning velocities of propanol isomers are measured in a high-pressure constant-volume cylindrical combustion vessel at the initial temperature of 423 K, pressures of 1–10 atm and equivalence ratios of 0.6–1.5. A general trend that n -propanol has much faster LBVs than i -propanol is noticed under all investigated conditions. A kinetic model of propanol isomers is developed and validated against the present experimental data, as well as other experimental data in literature covering wide ranges of temperatures, pressures and equivalence ratios. Rate of production analysis and sensitivity analysis are performed together to provide insight into the fuel isomeric effects on key reaction pathways and fuel reactivities. In the flow reactor pyrolysis, different dominant primary decomposition pathways of n -propanol and i -propanol lead to the differences in both molecular structures and concentration levels of pyrolysis products. In laminar flame propagation, different radical pool distributions of propanol isomers are illustrated and found to be largely influenced by fuel isomeric structures. The linear structure of n -propanol promotes the formation of more active radicals like formyl, vinyl and ethyl, while the branched structure of i -propanol facilitates the production of more stable radicals including methyl and allyl. Thus, the promoted chain-branching in n -propanol flames and enhanced chain-termination in i -propanol flames can explain the higher laminar burning velocities and reactivities of n -propanol than that of i -propanol.
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JOURNAL OF POWER SOURCES
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2019
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IF 7.467
Junjie He,Fan Zhang,Yuren Xiang,Jiarong Lian,Xin Wang,Youming Zhang,Xiao Peng,Pengju Zeng,Junle Qu,Jun Song
As a post graphene low dimensional material developed in the last two years, antimonene has attracted much attention. In contrast to graphite based low dimensional materials, antimonene is a bandgap semiconductor material, similar to black phosphorus, but its higher stability facilitates practical applications. Till to date, extensive theoretical studies have been conducted to explore their unique properties, but there are only a few experimental studies on their properties, let alone their applications. Therefore, in this study, high-quality antimonene oxide based low dimensional materials are prepared using a liquid exfoliation method in butanol . It is found that the antimonene oxide quantum dots have proper energy level alignment with CH 3 NH 3 PbI 3 . Consequently, they are successfully applied for perovskite solar cells based on copper doped nicklus oxide hole transfer layer, providing improved power conversion efficiency from 15.7% to near 18%. Detailed investigation shows that the performance improvement arises from enhanced charge extraction between hole transfer layer and perovskite. This study surely paves the way for the application of antimonene oxide based low dimensional materials in photovoltaic devices .
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CATALYSIS LETTERS
·
2019
·Vol. 150
·期 5
·1230-1237
·
IF 2.372
Zeng Rong,Liu Jiachen,Ding Shunmin,Sun Ling,Wu Ling,Cao Lvxin,Qiu Jiaxiang
Abstract Designing catalysts that achieve the rates and selectivities of natural enzymes is a long-standing goal in synthetic chemistry. Herein, the carboxyl-controlled-graphene oxide supported 3-aminopropyl-triethoxysilane (GO n -APTS) heterogeneous catalyts like the class I aldolases with –NH 2 and phenolic –OH groups were developed and applied in aldol reaction. The results demonstrate that the amount of –NH 2 groups and phenolic –OH groups play important roles of activity and selectivity, respectively. The most efficiency catalyst GO 8 -APTS shows an excellent conversion of over 90% with a high aldol product selectivity of about 89%. Furthermore, the catalyst can be easily recovered and reused at least 5 times without significant loss of the reactivity. Graphic Abstract
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MICROCHEMICAL JOURNAL
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2018
·
IF 2.746
Bin Zhou,Xin-Yi Yang,Yong-Sheng Wang,Jie-Can Yi,Zhen Zeng,Huan Zhang,Ya-Ting Chen,Xi-Jiang Hu,Qing-Li Suo
A label-free fluorescence aptasensor based on conformational switching of aptamer induced by Cd 2+ was established for the good selective determination of Cd 2+ . The aptamer could act as a recognition element for Cd 2+ . SYBR green I (SG), as a signal reporter, can bind to the small groove of double-stranded DNA (dsDNA) constituted the aptamer and the complementary strand, establishing the dsDNA-SG complex and generating high fluorescence intensity . In the presence of Cd 2+ , the specific recognition and binging of aptamers preferentially with Cd 2+ induce free of complementary strands from dsDNA and conformational switching of aptamer from dsDNA to a stem-loop structure, fluorescence intensity of system decrease dramatically. Under the optimum experiment parameters, the aptasensor shows a good linear range from 1.12 μg L −1 to 224.82 μg L −1 and the excellent detection limit as low as 0.34 μg L −1 . The relative standard deviations (RSD) for determination of Cd 2+ (n = 8) were lower than 4%, and the recoveries were in the range of 98.57% ~ 102.49%. The use of fluorescence aptasensor has good selectivity and does not require any sample treatment or target preconcentration for the detection of Cd 2+ in real samples.
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ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Jiangping Jing,Zhuoyuan Chen,Chang Feng
Graphitic carbon nitride (g-C 3 N 4 ) usually shows amphoteric property in a neutral solution. In this work, a K&I co-doped g-C 3 N 4 is prepared by simply sintering the mixture of dicyandiamine, KI and I 2 . The K&I co-doping modulates the band structure of g-C 3 N 4 with pulling the Fermi level toward its conduction band minimum. The obtained K&I co-doped g-C 3 N 4 (K&I-C 3 N 4 ) generates positive photocurrents over the whole investigated potential range, exhibiting a typical n-type semiconductor characteristic. Therefore, the K&I co-doping transforms the g-C 3 N 4 from amphoteric to n-type semiconductor. Also, the prepared K&I-C 3 N 4 shows widened light absorption range and enhanced separation efficiency of the photogenerated charge carriers, which results in the dramatically enhanced photoelectrochemical performance.
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INORGANIC CHEMISTRY
·
2014
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IF 4.794
Jun-Feng Liu,Xue Min,Jin-Yu Lv,Fu-Xing Pan,Qing-Jiang Pan,Zhong-Ming Sun
A family of di-, tri-, and tetranuclear copper(I) complexes supported by length-controlled silaamidinate ligands have been synthesized to show short CuI–CuI distances (2.43–2.62 Å) and feature a linear or bent metal–metal arrangement, which is elucidated by a relativistic density functional theory calculation.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2013
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IF 3.172
Guangfang Li,Fan Qin,Runming Wang,Shengqiang Xiao,Hongzhe Sun,Rong Chen
A facile microwave irradiation method has been successfully developed for the controllable fabrication of BiOX (X = Cl, Br, I) nanostructures in mannitol solution. The morphology and size of BiOX nanostructures could be readily tailored by adjusting the amount of halide, reaction precursor, and mannitol concentration. Mannitol molecule acts as both a capping agent and a cohesive agent in the formation of BiOX nanostructures. A possible two-stage formation mechanism was discussed based on the morphology evolution of BiOI nanostructures obtained in mannitol solution with different concentrations. The as-synthesized BiOX nanostructures exhibit much higher photocatalytic activities than that of commercial TiO 2 . In particular, flower-like BiOX hierarchical nanostructures display the best photocatalytic performance, which is mainly ascribed to their unique hierarchical structure, high BET surface area, and large band gap. Moreover, BiOX nanostructures also demonstrate superior Cr(VI) removal capacity. The Cr(VI) adsorption behavior was also analyzed by the Langmuir and Freundlich adsorption isotherms.
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