查找使用阿拉丁产品的科研文献

Preparation of F/Mn-doped CsPb(Br/Cl)3 quantum-dot glass and their luminescence properties

Zhuqing Sun,Yongxia Li,Haowen Bai,Shenghang Jin,Haibo Zhang,Guanying Cao

All inorganic lead halide cesium perovskite quantum dots (QDs) have attracted much attention due to their excellent luminescence properties, but further development is restricted by their stability and the existence of toxic element lead. In this paper, F/Mn-doped CsPb ( Br / Cl ) 3 QDs glass was prepared by melt quenching and heat treatment, with reduced Pb content effectively. The result shows that the spectrum of the QD glass is adjustable between 450 nm and 515.4 nm by changing the feeding ratio of Mn-Pb ion and heat treatment temperature. Moreover, the indraught of Mn 2 + effectively improves the PLQY of CsPb ( Br / Cl ) 3 QDs glass and serves as a red-emitting. The prepared composites not only maintain good fluorescence characteristics, but also greatly improve the stability of QDs. And successfully coupled with blue LED chips to synthesize WLED, Under 20 mA current, the color coordinate is (0.3446, 0.3389).

Regioselective B(3)–H bond activation based on an o-carboranyl dithiocarboxylate ligand and its derivatives

Run-Ze Yuan,Peng-Fei Cui,Shu-Ting Guo,Guo-Xin Jin

Herein, we describe the synthesis of tetraphenylphosphonium o-carboranyl dithiocarboxylate (Ligand 1) and methyldithiocarboxyl-o-carborane (Ligand 2). The complexes [Cp*M(o-C2B10H11CS2)Cl] (M = Ir (3); Rh (4)) and [Cp*M(o-C2B10H11CS2)2] (M = Ir (5); Rh (6)) have been synthesized based on Ligand 1. The selective B–H bond activation of Ligand 2 has also been explored, leading to the synthesis of the B–H activated complex [Cp*Ir(o-C2B10H10CS2CH3)Cl] (7) and four of its substituted derivatives (8, 9, 10 and 11). All of these compounds have been characterised through single-crystal X-ray diffraction, NMR, IR spectroscopy and elemental analysis.

Luminescent detection of pesticides by color changeable flexible coumarin-3-carboxylic acid/GdF3:Sm3+ composite film

Ziyu Chen,Zejia Zhao,Jiaxin Yang,Xiaoli Gao,Xu Sang,Adnan Khan,Rui Xu,Ming Feng,Lisa Liu,Qixin Liu,Feng Song

The utilization and residue of pesticides exist multifaceted non-restrictive effects on food safety and ecological protection. Exploitation of rapid and sensitive pesticide detection technology is imperative and will be helpful to better control the detriment of pesticides. Here, a novel flexible film has been prepared based on organic-inorganic composite materials (coumarin-3-carboxylic acid and GdF 3 :Sm 3+ ), which exhibits good optical performance and can well realize the timely and maneuverable detection for different pesticides. The spectra and luminescence properties of each composition in the composite have been analyzed systematically, and the coordinated fluorescence emission of Sm 3+ and coumarin-3-carboxylic acid is revealed at an excitation wavelength of 373 nm. Besides, the energy transfer mechanism is also researched by both experiment and theoretical calculation. The actual detection of different pesticides reveals differential fluorescence influence degree. Meanwhile, the flexible film still possesses sensitive recognition in the presence of micro concentration of pesticides. Results indicate that the flexible film with good optical performance can produce visual detection ability and provide a promising strategy for wider detection applications.

Effect of In(OH)3 species modified ZnS on improved photocatalytic activity of photoreduction of CO2

Qiao Zhao,Hanbo Li,Yaan Cao

A series of the In(OH) 3 species modified ZnS (ZnS–In(OH) 3 X% (X ​= ​2, 5, 7, 10)) photocatalysts were synthesized by a hydrothermal method . ZnS–In(OH) 3 X% (X ​= ​2, 5, 7, 10) exhibited the improvement of photocatalytic activity for the photoreduction of CO 2 into CO compared with ZnS. Characterized by X-ray diffraction (XRD), fourier transforms infrared spectra (FT-IR), high resolution transmission electron microscope (HRTEM), X-ray photoelectron spectroscopy (XPS) valence band spectra, UV–vis diffuse reflectance spectra, photoluminescence (PL) and time-resolved PL decay curves, the crystal structure, band structure and behaviors of photogenerated charge carriers for photocatalyst were explored up. It was revealed that the modification of In(OH) 3 surface species on surface of ZnS can prolong the fluorescence lifetimes of photogenerated charge carriers, enhance the separate of photoinduced charge carriers efficiently and promote better matching between the band structure and the redox potential of the CO 2 /CO, resulting in improvement of photocatalytic activity efficiently for ZnS–In(OH) 3 X% (X ​= ​2, 5, 7, 10) photocatalysts . This work may offer a new understanding to study the effect of surface species modification on photocatalytic performance of photocatalyst.

Synthesis of deuterium-labeled 2-quinoxalinecarboxylic acid and 3-methylquinoxaline-2-carboxylic acid from deuterium aniline

Wulian Chen,Chaomin Zhao,Xiaojun Deng

An efficient and simple synthetic route of deuterium-labeled 2-quinoxalinecarboxylic acid- d 4 (QCA- d 4 ) and 3-methylquinoxaline-2-carboxylic acid- d 4 (MQCA- d 4 ) is presented with 99.9% and 99.6% isotopic enrichment using aniline- d 5 as labeled starting material. Their chemical structures were confirmed by 1 H NMR, and their isotopic abundance was determined by mass spectrometry analysis.

Influence of thermal effect on upconversion luminescence of Y2(MoO4)3:Yb3+, Ln3+ (Ln = Er, Tm)

Tao Pang,Wenbo Peng

Upconversion luminescence of Yb3+/Er3+ and Yb3+/Tm3+ co-doped Y2(MoO4)3 phosphors under 980 nm excitation is investigated. It is demonstrated that Yb3+ co-doping causes a significant thermal effect. For Yb3+ and Er3+ co-doped case, the thermal effect, the long-distance energy migration and the energy transfer from Er3+ to Yb3+ are responsible for the abnormal luminescence quenching. In the case of Yb3+ and Tm3+ co-doped, the thermal effect improves the excited efficiency of Tm3+, and thus the luminescence of Tm3+ continues to strengthen at the Yb3+ concentration that causes Er3+ luminescence quenching. These results contribute to the design of the efficient upconversion materials.

Improved piezoelectric properties in Bi(Mg2/3Nb1/3)O3-modified BiFeO3–BaTiO3 lead-free piezoelectric ceramics

Hailan Qin,Jianwei Zhao,Xiaoxin Chen,Hongtian Li,Shenghao Wang,Yuxiao Du,Ahmad Azmin Mohamad,Huanfu Zhou,Dawei Wang

The investigation of lead-free ceramics with exceptional piezoelectric properties holds great importance in the substitution of lead-based materials, hence promoting the development of green technology and fostering an environmentally sustainable society. This study successfully synthesized two series of Bi(Mg 2/3 Nb 1/3 )O 3 (BMN)-modified BiFeO 3 –BaTiO 3 (BF–BT) lead-free piezoelectric ceramics using the conventional solid-state reaction approach. The phase structure, microstructure, dielectric, and piezoelectric properties of these ceramics were comprehensively investigated. A typical perovskite structure is observed in all probed compositions, and the associated phase structure undergoes a gradual transition from a rhombohedral-cubic phase mixture to a cubic-dominant phase structure as increases the content of BMN and BT. All compositions exhibit obvious core–shell microstructures with inhomogeneous element distributions. Most importantly, the BF–0.30BT–0.005BMN and BF–0.34BT–0.03BMN piezoelectric ceramics presented remarkable values for the piezoelectric coefficient (225 pC/N) and converse piezoelectric coefficient (396 pm/V), respectively. These findings highlight the potential of BMN-modified BF–BT ceramics for use in high-performance piezoelectric applications.

A Preliminary Study on a New Epoxy Resin IR-3 for High-Field Superconducting Magnet Applications

Huanli Yao,Yalin Zhao,Hua Zhang,Yingzhe Wang,Chengtao Wang,Zhen Zhang,Ze Feng,Jinrui Shi,Xin Chen,Jin Zhou,Chunyan Li,Juan Wang,Feipeng Ning,Rongjin Huang,Qingjin Xu

Preparation and characterization of poly (3-hexylthiophene) / carbon nanotubes hybrid material via in-situ click chemistry

Zhenglong Yang,Jing Yu,Kangyu Fu,Fengfeng Tang

The poly(3-hexylthiophene) - multiwalled carbon nanotube hybrid material (P3HT-MWCNT) was successfully prepared in the Cu(I)/DBU catalyst system via in-situ click reaction. The properties of P3HT-MWCNT were measured by FTIR, 1 H NMR, UV-vis, XRD , TEM , SEM . The fluorescence spectrum of P3HT-MWCNT proved the covalent bond between P3HT and MWCNT, and P3HT could be coated on the surface of MWCNT. Compared with the physical blends of P3HT and MWCNT, P3HT-MWCNT prepared by click chemistry exhibited better thermal stability and a higher melting point of 243.2 °C. TG results also indicated that P3HT content of P3HT-MWCNT was 21.4%. It was expected to prepare novel organic-inorganic donor-acceptor hybrid material with good solubility, optical and thermal stability, which may be a promising material applied in preparation of organic photoelectron in the future.

Simple and rapid detection of free 3-monochloropropane-1,2-diol based on cysteine modified silver nanoparticles

Aka Alla Martin,Essy Kouadio Fodjo,Gouli Bi Irié Marc,Trokourey Albert,Cong Kong

A rapid colorimetric method using cysteine-modified silver nanoparticles (Cys-AgNPs) is applied for the detection of 3-monochloropropane-1,2-diol (3-MCPD). Indeed, in the presence of 3-MCPD, the color of Cys-AgNPs solution changes from yellow to pink within five minutes at 100 °C and pH 9.3. This change is mainly attributed to the ability of amino group of cysteine to react with 3-MCPD to form N-(2,3-dihydroxypropyl)-amino acid grafted on AgNPs (3-MCPD-Cys-AgNPs) in alkaline medium. This color change makes 3-MCPD to be clearly detectable by unassisted visual means even at 0.1 μg⋅mL −1 . Besides, using UV–Vis spectroscopic technique, a linear range from 0.1 μg⋅mL −1 to 1.25 μg⋅mL −1 for 3-MCPD detection is obtained, with a calculated detection limit of 0.084 μg⋅mL −1 . These results suggest that this sensing technique is sensitive to 3-MCPD and may have a substantial application in the rapid detection of food contaminants particularly, where quality and safety of food products are paramount concern.

A regiosymmetric blue-to-transmissive electrochromic polymer based on 3, 4-ethylenedioxythiophene with bromomethyl pendant groups

Xiaoming Chen,Mingdi Yang,Qishu Qu,Qingchun Zhao,Wensheng Zou

The synthesis and electrochromic properties of a novel regiosymmetric polymer based on 3,4-ethylenedioxythiophene, poly(2,3-bis(bromomethyl)-2,3-dihydrothieno[3,4-b][1,4]dioxine) (PEDOT(MeBr) 2 ) were highlighted. The monomer was electrochemically polymerized via repetitive cycling between 0 and 1.8 V in lithium perchlorate (LiClO 4 )–acetonitrile (ACN) electrolytic medium. The corresponding polymer was characterized by FTIR spectra, scanning electron microscopy, cyclic voltammetry , UV–Vis-NIR spectroscopy and colorimetry . It features a reversible redox process and demonstrates a stable blue-to-transmissive electrochromic behavior with very low driving potentials (−0.1 and 0.65 V). Additionally the polymer film exhibits enhanced optical contrast (60% at 669 nm) and improved coloration efficiency (183.1 cm 2 /C at 100% full contrast during bleaching process) which are higher than those of PEDOT, a relatively longer response time compared with PEDOT and reasonable redox stability.

[C(NH2)3]2S2O8: combining delocalized and localized π-conjugate units to achieve strong optical anisotropy

Man Zhang,Bingbing Zhang,Daqing Yang,Ying Wang

A new birefringent crystal [C(NH2)3]2S2O8 was obtained by combining the π-conjugated [C(NH2)3] cation and the [S2O8] groups with localized O–O π-bonds. Optical measurements show that the UV cutoff wavelength of [C(NH2)3]2S2O8 is 222 nm, and its birefringence is 0.102 at 546 nm. The calculated results show that its large birefringence is attributed to the synergistic effect of the [C(NH2)3] and [S2O8] units, which is the first case among known birefringent crystals. These results provide new insights into the design of superior birefringent materials.