查找使用阿拉丁产品的科研文献

High performance n-type thermoelectric material based on naphthalenediimide radical anions

D. Zhao,Q. Jiang,Y. Jia,J. Zhou,N. Zheng,D. Hu,Y. Ma

An ideal organic thermoelectric (TE) material should possess features that would be low-cost, of high performance, easy to process, and non-toxic, but it is rare to find materials that meet these requirements. Naphthalenediimide (NDI), as a common and cheap industrial pigment, displays strong intermolecular inaction and good n-type semiconductor character. However, due to the strong interaction of π-π and hydrogen bond interaction, NDI usually exhibited poor solubility, making it difficult to process in solution. Herein, we demonstrated that the unsubstituted NDI could form a suspension mixed with NDI radical anion state by phenyl lithium doping, which consequently can be used to prepare dense film by drop-casting for TE application. More importantly, by optimizing the doping ratio, the TE film reached electrical conductivity of 0.11 S cm −1 and Seebeck coefficient of −1289 μV K −1 . Eventually, a high power factor up to 18.8 μW m −1  K −2 and ZT value of 0.053 was obtained, which is one of the best TE performance achieved in n-type NDI-based TE materials. This work suggests the simple strategy of utilizing commercially mature molecules to develop organic TE materials with high performance.

Rapid Electrochemical Sensing of Zn(II) Using MesoporousMnO2@N-Graphene Composites

Xiangle Meng,Xiuxiu Dong,Dong Liu,Qijian Niu,Shun Lu,Tianyan You

Synthesis and bacterial inhibition of novel Ag2S–N–CQD composite material

Wang Kunjie,Liang Lei,Xu Jialin,Li Hongxia,Du Mei,Zhao Xiaoliang,Zhang Deyi,Feng Huixia,Fan Haiyan

The present work aims to combine carbon quantum dots (CQDs) with the good water solubility, biocompatibility, and low toxicity and nano-sized silver sulfide with excellent antibacterial effect in the synthesized composite. The composite was further treated with polyethyleneimine (PEI) and conjugated with graphene oxide (GO). The as-prepared composite Ag 2 S–CQDs–PEI–GO exhibits a core of Ag 2 S with the size of 20–50 nm and the shell of CQDs with the average particle size of 1.8 nm. The core shell structure is loaded on the template of PEI–GO. Strong antibacterial effect was observed on Ag 2 S–CQDs composite against four strands of bacteria Staphylococcus aureus ( S. aureus ), Escherichia coli ( E. coli ), Enterococcus faecalis ( E. faecalis ), and Pseudomonas aeruginosa ( P. aeruginosa ). We briefly discussed the bacteriostatic mechanism of the composite. The as-prepared composite has huge potential in the development of biomedicine.

Silicene/poly(N-isopropylacrylamide) smart hydrogels as remote light-controlled switches

Tiantian Fang,Xifan Chen,Changyu Yang,Yaqi Cao,Junshi Zhang,WenChao Peng,Yang Li,Fengbao Zhang,Xiaobin Fan

Smart hydrogels with good flexibility and biocompatibility have been widely used. The common near-infrared (NIR) photothermal agents are facing a trade-off between good photothermal-conversion efficiency and high biocompatibility. Therefore, developing new metal-free photothermal agents with low cost, high biocompatibility and excellent phase stability is still in urgent need. In this study, we successfully combined poly( N -isopropylacrylamide) (PNIPAM) with the two-dimensional (2D) silicene nanosheets via the in situ polymerization method. Attributed to the thermal-responsive nature of PNIPAM and the excellent photothermal properties of 2D silicene, the obtained silicene/PNIPAM composite hydrogels exhibited dual thermal and NIR responsive properties. This smart hydrogel showed rapid, reversible and repeatable NIR light-responsive behaviors. The volume of this smart hydrogels can shrink significantly under NIR irradiation and recover to its original size without the NIR irradiation. Remote near-infrared light-controlled microfluidic pipelines and electronic switches based on obtained silicene/PNIPAM composite hydrogels were also demonstrated. This work significantly broadens the application prospects of silicene-based hydrogels in remote light-controlled devices.

Preparation of ZnNb2O6/N-doped carbon composites for lithium ion storage

Xuefeng Li,Jing Li,Rai Nauman Ali,Zhi Wang,Guojing Hu,Bin Xiang

Recently, conductive M-Nb-O composites have gained much attention as a novel lithium ion storage anode material. However, the conductivity and rate performance of M-Nb-O composites still need to be further enhanced. Herein, we have designed a facile strategy to prepare ZnNb 2 O 6 /N-doped carbon (ZnNb 2 O 6 /NC) which is derived from Nb 2 O 5 @zeolitic imidazole frameworks precursor. The ZnNb 2 O 6 /NC exhibits advanced energy storage properties including high initial capacity (673 mA h g −1 at 100 mA g −1 ), superior reversible specific capacity (412.6 mA h g −1 until 100 cycles at 100 mA g −1 ), long-term cyclic stability and excellent rate capability (470.5 mA h g −1 after 800 cycles at a relatively high current density of 2 A g −1 ).

Synthon Polymorphism and π–π Stacking in N-Phenyl-2-hydroxynicotinanilides

Yunping Zhoujin,Xing Yang,Mingtao Zhang,Ju Guo,Sean Parkin,Tonglei Li,Faquan Yu,Sihui Long

A lactam–lactam dimer (LLD) and lactam NH···O═C (amide) catemer (LAC) are two competing motifs in N-phenyl-2-hydroxynicotinanilides (PHNAs). Steric effects play an important role in determining the outcome of this competition, and in general, PHNAs with no or negligible steric hindrance take on a near-planar conformation and form LLDs, rather than the widely observed amide NH···O═C hydrogen-bond chains. Conversely, those with significant steric hindrance are forced to take on a twisted conformation and form a lactam NH···O═C (amide) hydrogen bond. Nevertheless, steric factors are not the only criteria, as an LLD and an LAC have been observed in the two polymorphs (1-I and 1-II) of 2-hydroxy-N-m-tolyl-nicotinamide (namely 2-oxo-1,2-dihydropyridine-3-carboxylic acid m-tolylamide, compound 1), although the molecules in both forms have a nearly identical conformation, in contrast to five other newly synthesized PHNAs (2–6), whose crystal structures are sustained on the LLD. Thus, synthon polymorphism is possible in conformationally planar PHNAs. Theoretical studies were performed to provide an explanation for this observation. The lattice energies of the two forms of 1 showed only an insignificant difference. A Hirshfeld analysis revealed that the loss of stability due to less hydrogen bonding in 1-II is compensated by the participation of π–π stacking. Other than the commonly observed LLD in the crystals, π–π stacking provides a significant stabilization for each crystal, with its particular effects being dependent on the substitution pattern of the compound. A noncovalent interaction (NCI) analysis further provided a visual demonstration of the important intermolecular interactions. Potentially the other planar compounds could behave in a similar manner.

Adsorption and separation properties of n-pentane/isopentane on ZIF-8

Lin Zhang,Gang Qian,Zongjian Liu,Qun Cui,Haiyan Wang,Huqing Yao

Adsorption equilibrium and kinetic data is essential for the design of an adsorption process. In this work, the adsorption isotherms of n-pentane/isopentane on zeolitic imidazolate framework material (ZIF-8) were measured at 308, 343 and 373   K over the pressure range from 0 to 9.7   kPa by a gravimetric system. The equilibrium adsorption capacity at 303   K and 9.7   kPa is 0.2504   g   g −1 for n-pentane and 0.1439   g   g −1 for isopentane. Langmuir model was used to fit the adsorption isotherms. The adsorption kinetics of n-pentane/isopentane was studied at 308   K in the pressure range from 0 to 69.9   kPa. The data was well fitted with linear driving force model (LDF) model. The adsorption rate constant of n-pentane is from 0.0019 to 0.0326   s −1 , which is higher than that of isopentane, represented 0.0007–0.0036   s −1 . The adsorption selectivity of n-pentane/isopentane on ZIF-8 was contrast by the measurement of the binary breakthrough experiments at 343   K, 363   K and 393   K in the partial pressure of 7   kPa. When the adsorption temperature is 363   K, the adsorption selectivity of n-pentane/isopentane on ZIF-8 reaches the maximum 55. Compared with 5A molecular sieve, the desorption temperature of n-pentane on ZIF-8 was analyzed by temperature-programmed-desorption (TPD) method. The peak temperature of n-pentane desorption on ZIF-8 is 361   K. However are 392   K and 443   K on a 5A molecular sieve. Thus, ZIF-8 is more selective or preferential adsorption for n-pentane in comparison to isopentane molecules at low temperature.

Wheat straw cellulose dissolution and isolation by tetra-n-butylammonium hydroxide

Chao Zhong,Chunming Wang,Fan Huang,Honghua Jia,Ping Wei

In this article, a novel and high efficient solvent, tetra - n -Butylammonium Hydroxide (TBAH), was used for dissolution and isolation of straw cellulose from wheat straw. The composition analysis with gas chromatography (GC) and the spectroscopic characterization analysis conducted by X-Ray diffraction (XRD)/Fourier transform infrared spectroscopy (FTIR) indicated that straw cellulose can be directly dissolved and isolated by TBAH without derivatization . The investigation on the properties of straw cellulose isolation was based on the results of single factor experiments and orthogonal experiments, with optimum conditions for straw cellulose isolation being obtained as follow: reaction temperature 60   °C, reaction time 40   min, concentration of TBAH 50% and ratio of TBAH to straw 10:1 (m/m). In addition, as a solvent for cellulose, TBAH could be recycled several times with high activity being retained.

Highly Sensitive Triethylamine Sensors Enabled by Co3O4/ZnO p-n Heterojunctions

Lin Wang,Haili Huang,Dongdong Zhang,Hung-Chun Wu,Meiling Li,Huilin Hou,Weiyou Yang,Xuhui Yu,Zonghua Wang

Triethylamine (TEA) is a typically volatile organic compound that poses significant environmental and health risks, due to its high toxicity and volatility. Currently, the exploration of TEA sensors based on semiconductor ZnO is still suffered by their intrinsically low sensitivity, slow response/recovery times, and poor selectivity. Herein, we develop the highly-sensitive TEA sensors based on rationally-designed Co 3 O 4 /ZnO p-n heterojunctions, in which the clustered Co 3 O 4 are incorporated into porous ZnO nanosheets. As a result, at the given operating temperature of 260 °C, the as-constructed sensors exhibit an overall enhanced performance with an excellent response of 140.5 to 100 ppm TEA, swift response/recovery times of 6/60 s and high selectivity, representing their promise toward practical applications in advanced TEA sensors.

N-type tetragonal phase Mo:BiVO4 thin film with hydrogen production activity

Fuhao Liu,Zhiguo Yuan,Sen Zhao,Quande Che,Qian Ma,Junpeng Wang

Tetragonal BiVO 4 nanorod array exhibits excellent carrier transport properties, but due to its p-type conductivity, it can only be used as a photocathode. In this study, an n-type tetragonal BiVO 4 nanorod array doped with molybdenum was successfully fabricated on fluorine-doped tin oxide (FTO) glass substrates via the hydrothermal method. The doping of Mo and its corresponding concentration were accurately ascertained through X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma (ICP) techniques. Computational simulations revealed that Mo doping induces a shallow donor level beneath the conduction band of BiVO 4 . Notably, the structure and morphology of BiVO 4 did not undergo significant changes after Mo doping, but the conductivity type and conductivity of the surface samples were greatly improved as evidenced by Mott-Schottky and conductive atomic force microscopy (C-AFM) measurements. Impressively, the onset potential for oxygen production when utilized as a photoanode was merely 0.2 V vs RHE. More importantly, although its conduction band position is slightly lower than the hydrogen production potential, the doped sample still demonstrated outstanding activity in water splitting for hydrogen generation.

Green–Light–Driven Poly(N-isopropylacrylamide-acrylamide)/Fe3O4 Nanocomposite Hydrogel Actuators

Cao Ying,Li Wenjiao,Quan Fengyu,Xia Yanzhi,Xiong Zhong

Light-responsive hydrogel actuators show attractive biomedical applications for in vivo drug delivery tool, surgical tissue repair operation, and vascular cleaning due to its non-contact, rapid, precise, and remote spatial control of light. Conventional visible–light–responsive hydrogels contain special chemical structure or groups, and the difficulty in synthesis results in that few can be applied to fabricate visible–light–driven hydrogel actuators. In this study, based on photothermal effect, surface-modified Fe3O4 nanoparticles were incorporated into poly(N-isopropylacrylamide-acrylamide) hydrogel by UV photopolymerization, which revealed excellent green–light–responsive volume change. Under a laser irradiation of 200 mW at 520 nm, the bending angle deformation of hydrogel strips with 2.62 wt% Fe3O4 reached 107.8°. Strip-shaped hydrogel actuators could be applied to transport tiny objects. Furthermore, a boomerang-like hydrogel actuator was designed and fabricated to drive floating foam on water. By 12 cycles of continuous laser on–off irradiation to a hydrogel actuator underwater, a circular returning movement of the float was accomplished. The study on driving a float using visible–light–triggered hydrogel actuators provides a new idea for the design of light-driven biomedical devices and soft robots.

Hierarchical Structures Advance Thermoelectric Properties of Porous n-type β-Ag2Se

Jie Chen,Qiang Sun,Deyu Bao,Taoyi Liu,Wei-Di Liu,Can Liu,Jun Tang,Dali Zhou,Lei Yang,Zhi-Gang Chen

Owing to the intrinsically good near-room-temperature thermoelectric performance, β-Ag2Se has been considered as a promising alternative to n-type Bi2Te3 thermoelectric materials. Herein, we develop an energy- and time-efficient wet mechanical alloying and spark plasma sintering method to prepare porous β-Ag2Se with hierarchical structures including high-density pores, a metastable phase, nanosized grains, semi-coherent grain boundaries, high-density dislocations, and localized strains, leading to an ultralow lattice thermal conductivity of ∼0.35 W m–1 K–1 at 300 K. A relatively high carrier mobility is obtained by adjusting the sintering temperature to obtain pores with an average size of ∼260 nm, therefore resulting in a figure of merit, zT, of ∼0.7 at 300 K and ∼0.9 at 390 K. The single parabolic band model predicts that zT of such porous β-Ag2Se can reach ∼1.1 at 300 K if the carrier concentration can be tuned to ∼1 × 1018 cm–3, suggesting that β-Ag2Se can be a competitive candidate for room-temperature thermoelectric applications.