Journal of Physics Communications
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2020
·Vol. 4
·期 4
·045016
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IF 0
Jiahu Wei,Feng Li,Chun Chang,Qin Zhang
Indium-rich environmentally-friendly quantum dots (QDs) have received widespread attention due to the absence of cadmium. In this paper, AgInS2 (AIS) QDs are synthesized by hot injection method. By adjusting the ratio of indium/silver (In/Ag = 1, 2, 3, 4, 5), the AIS QDs exhibit a blue shift from 868 nm to 603 nm with the indium composition increases. Therein, the AIS QDs with the ratio of In/Ag = 4 show a highest photoluminescent (PL) quantum yields (QYs) up to 57%. AIS QDs are coated with ZnS shell to passivate the surface defects, and the PL QYs of obtained core/shell AIS/ZnS QDs is increased to 72%. By using these AIS/ZnS QDs as light emitters, light emitting diodes are assembled with a stacked multi-layer structure ITO/PEDOT:PSS/Poly-TPD/QDs/ZnO:Mg/Al. The resulted electroluminescent (EL) device exhibits a maximum external quantum efficiency (EQE) of 1.25% and an open circuit voltage of 4.6 V corresponding to a maximum brightness of 1120 cd m−2. Although the performances of the as fabricated AIS/ZnS-based device lag much behind than those of the Cd-based ones, they are expected to be enhanced with much more studies on the synthesis of the QDs and the optimization of device structure.
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BULLETIN OF THE KOREAN CHEMICAL SOCIETY
·
2020
·Vol. 41
·期 5
·552-557
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IF 0.611
Shan Li,Zhongping Chen,Datong Wu,Yong Qin,Yong Kong
A novel composite of graphene quantum dots functionalized Sb 2 WO 6 (GQDs/Sb 2 WO 6 ) was prepared by an electrostatic self-assembly method and used as a photocatalyst for the degradation of an organic pollutant. The resulting GQDs/Sb 2 WO 6 was characterized by electron microscopy and optical measurements. The photocatalytic activity of GQDs/Sb 2 WO 6 was investigated by degrading methyl orange (MO) under UV-light and visible-light irradiation. Compared with pure Sb 2 WO 6 , enhancement of the photocatalytic performance of GQDs/Sb 2 WO 6 was achieved, and the degradation efficiency for MO was almost 100% within 3 h under UV-light irradiation and 71.4% within 3 h under visible-light irradiation. The photocatalytic degradation mechanism of GQDs/Sb 2 WO 6 was illustrated by free radical and hole scavenging experiments, and the main active species were confirmed to be holes (h + ) and superoxide anion radicals (O 2 · − ). Moreover, the GQDs/Sb 2 WO 6 composites exhibited high recyclability and stability and had potential application for decomposing other organic contaminants in water.
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高影响因子
Nanomaterials
·
2020
·Vol. 10
·期 4
·805
·
IF 4.324
Bo Zhang,Xiangfeng Peng,Zhao Wang
Composites of g-C3N4/TiO2were one-step prepared using electron impact with dielectric barrier discharge (DBD) plasma as the electron source. Due to the low operation temperature, TiO2by the plasma method shows higher specific surface area and smaller particle size than that prepared via conventional calcination. Most interestingly, electron impact produces more oxygen vacancy on TiO2, which facilitates the recombination and formation of heterostructure of g-C3N4/TiO2. The composites have higher light absorption capacity and lower charge recombination efficiency. g-C3N4/TiO2by plasma can produce hydrogen at a rate of 219.9 μmol·g−1·h−1and completely degrade Rhodamine B (20mg·L−1) in two hours. Its hydrogen production rates were 3 and 1.5 times higher than that by calcination and pure g-C3N4, respectively. Electron impact, ozone and oxygen radical also play key roles in plasma preparation. Plasma has unique advantages in metal oxides defect engineering and the preparation of heterostructured composites with prospective applications as photocatalysts for pollutant degradation and water splitting.Keywords:dielectric barrier discharge plasma;oxygen vacancy;g-C3N4/TiO2;photodegradation;H2evolution
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PubMed
高影响因子
Bioresources and Bioprocessing
·
2020
·Vol. 7
·期 1
·1-13
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IF 0
Zhao Jianbo,Liang Xingxing,Cao Hui,Tan Tianwei
Photo-controlled release hydrogel provides a new strategy for treating tumours. Under the stimulation of external light sources, the ability to release the entrapped drug on time and space on demand has outstanding advantages in improving drug utilisation, optimising treatment, and reducing toxicity and side effects. In this study, a photo-controlled drug delivery system for disulphide cross-linked polyaspartic acid (PASP-SS) hydrogels encapsulating proteinase K (ProK) adsorbed with platinum nanoparticles (PtNPs) was designed. The injectable cysteamine-modified polyaspartic acid (PASP-SH) sol and PtNPs adsorbed by ProK (ProK-PtNPs) as regulatory factors were prepared. Then, ProK-PtNPs and lentinan were dissolved in the sol, and the oxidant was added to the matrix to form the gel in situ quickly after injection. Finally, the degradation of PASP-SS hydrogel by ProK and the controllability of drug release under near-infrared (NIR) light irradiation were elucidated. In vitro degradation of hydrogels and drug release experiments showed that the degradation rate of PASP-SS hydrogel significantly increased and the drug release rate increased significantly under near-infrared radiation. The results of cytotoxicity test showed that PASP-SS, ProK-PtNPs, and lentinan all had more than 90% cell survival rate on NIH3T3, and the lentinan released from the carrier obviously inhibited the proliferation of MCF7. PASP hydrogel has the potential to respond to on-demand light control.
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ACS Catalysis
·
2019
·
IF 12.221
Kaiyi Su,Huifang Liu,Bin Zeng,Zhixin Zhang,Nengchao Luo,Zhipeng Huang,Zhuyan Gao,Feng Wang
Photocatalytic selective oxidation of hydrocarbons to oxygenated chemicals greatly relies on catalytic materials that show high efficiency of photogenerated holes and electrons separation and visible light absorption capacity. We, herein, report one facile calcination approach with ammonium chloride and melamine as the template to synthesize nitrogen-modified Nb2O5 nanomeshes material (Nb2O5-N), which exhibits a 37-fold reaction rate larger than its commercial counterpart in photocatalytic oxidation of toluene into benzaldehyde under visible light irradiation. The reactivity is ascribed to an extended absorption spectrum within 700 nm by nitrogen modification. In addition, photocurrent response results suggest that a relaxation effect induced by nanomesh structure is beneficial for the separation of charge carriers for enhanced reactivity. This work sheds light on regulating the structure of metal oxides and the application of nanomesh materials in photocatalytic hydrocarbon conversion.
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高影响因子
CELLULOSE
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2019
·Vol. 27
·期 2
·743-753
·
IF 3.917
Chen Junyu,Mao Liucheng,Qi Hongxu,Xu Dazhuang,Huang Hongye,Liu Meiying,Wen Yuanqing,Deng Fengjie,Zhang Xiaoyong,Wei Yen
Abstract In recent years, cellulose nanocrystal (CNC) based materials have attracted great research attention for different applications owing to their unique properties and facile modification chemistry. In this work, CNC based thermo-responsive fluorescent composites were successfully prepared via the metal-free surface-initiated atom transfer radical polymerization (ATRP) of NIPAAm and a Schiff base containing dye (HDPAP). Results demonstrated CNC-poly (NIPAAm–HDPAP) composites display sensitive temperature-responsive coil-to-globule transition behavior at the temperature of lower critical solution temperature. The bright fluorescence offered by the Schiff base dye (HDPAP) was also confirmed by fluorescence spectra. Moreover, the preparation method of light meditated ATRP was proved to become the promising way in fabrication of multifunctional nanomaterials for its incomparable advantages, including low energy consumption, high efficiency, good monomer adaptation, free of transition metal ions. Graphic abstract
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高影响因子
Polymer Chemistry
·
2019
·Vol. 10
·期 47
·6481-6488
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IF 4.76
Beibei Wang,Lijian Liu,Liqiong Liao
Here, light and ferric ion (Fe3+) responsive fluorochromic hydrogels with high strength and self-healing ability were designed and synthesized. The hydrogels were prepared via physical crosslinking of poly(vinyl alcohol) (PVA), in the presence of γ-cyclodextrin-spiropyran (γ-CD-SP) and tannic acid (TA). By utilizing the hydrogen bonding interaction between the γ-CD moiety and PVA chain, the fluorophore γ-CD-SP could be incorporated into the PVA gel successfully. Owing to photo-isomerization of the SP moiety, the hydrogel showed “on/off” fluorescence behavior upon ultraviolet/bright light irradiation. Moreover, the fluorescence emission of the hydrogel could also be turned off in the presence of Fe3+ by fluorescence inner filter effects, and then recovered by adding EDTA. The hydrogel possessed high tensile strength (i.e. 2.18 MPa) and self-healing ability. With the features of high strength, self-healing, and tunable fluorescence properties, the hydrogels would have potential applications in wearable devices, fluorescent sensors, and optical switches.
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高影响因子
Journal of Materials Chemistry C
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2019
·Vol. 8
·期 4
·1319-1325
·
IF 6.641
Siyuan Zeng,Shasha Shi,Shirong Wang,Yin Xiao
Achieving efficient blue emission with spectrum stability in perovskite light-emitting diodes (PeLEDs) is a great challenge, although the external quantum efficiency (EQE) of PeLEDs for red and green emission has exceeded 20%. Here, we report efficient sky-blue PeLEDs with high brightness based on mixed-ligand confined quasi-2D perovskites. By detailed characterization of the optical and physicochemical properties of n-butylammonium (BA) or 2-phenylethylammonium (PEA)-based perovskites with various alkyl ammonium bromides as co-ligands, it is found that the molecular size and charge on the amino-groups of the co-ligand hold the key to constructing effective mixed-ligand systems. Accordingly, dimethylammonium (DMA) is an ideal co-ligand in both BA- and PEA-based quasi-2D perovskites. Thanks to its appropriate molecular size, DMA could help to confine the diameter of perovskite nanocrystals (NCs) and improve their dispersity in organic ligands. Besides, DMA is prone to disperse among PEA or BA molecules to cap the perovskite synergistically, and the phase of n = 1 caused by excess co-ligands could be effectively avoided benefiting from the relatively weak coordination ability of DMA due to the relatively small positive charge on amino-groups. The optimized PeLEDs based on BA2DMA1.6Cs2Pb3Br11.6 and PEA2DMA1.2Cs2Pb3Br11.2 exhibit color-stable sky-blue (490 nm) and bluish green (499 nm) emission with a record maximum luminance of 2825 and 7760 cd m−2 respectively. The applicability of this approach in the red emission region is also demonstrated, which provides a versatile strategy for full spectrum modulation.
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高影响因子
ACS Catalysis
·
2019
·
IF 12.221
Huifang Liu,Hongji Li,Nengchao Luo,Feng Wang
Lignin is the largest carrier of aromatics on earth, and its depolymerization can afford value-added aromatic products. Direct cleavage of the C–C bonds in lignin linkages is significant, but it is challenging to obtain low-molecular-weight aromatic monomers. Herein, using vanadium catalysts under visible light, we selectively cleave the C–C bonds in β-1 and β-O-4 interlinkages occluded in lignin models and extracts by an oxidative protocol. Visible light irradiation triggered single electron transfer between the substrate and the catalyst, which further induced the selective Cα–Cβ bond cleavage and generated the final aromatic products through radical intermediates. Using this photocatalytic chemistry, the reactivity of lignin models and the selectivity of Cα–Cβ bond cleavage were significantly improved. More importantly, this protocol affords aromatic monomers through the fragmentation of organosolv lignins even at room temperature, indicating the potential of photocatalytic C–C bond cleavage of lignin linkages under ambient conditions.
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高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2019
·Vol. 29
·期 51
·1903607
·
IF 15.621
Jinghui Li,Peipei Du,Shunran Li,Jing Liu,Menghua Zhu,Zhifang Tan,Manchen Hu,Jiajun Luo,Deqiang Guo,Lin Ma,Zhaogang Nie,Ying Ma,Liang Gao,Guangda Niu,Jiang Tang
Light-emitting diodes (LEDs) based on lead halide perovskites demonstrate outstanding optoelectronic properties and are strong competitors for display and lighting applications. While previous halide perovskite LEDs are mainly produced via solution processing, here an all-vacuum processing method is employed to construct CsPbBr 3 LEDs because vacuum processing exhibits high reliability and easy integration with existing OLED facilities for mass production. The high-throughput combinatorial strategies are further adopted to study perovskite composition, annealing temperature, and functional layer thickness, thus significantly speeding up the optimization process. The best rigid device shows a current efficiency (CE) of 4.8 cd A −1 (EQE of 1.45%) at 2358 cd m −2 , and best flexible device shows a CE of 4.16 cd A −1 (EQE of 1.37%) at 2012 cd m −2 with good bending tolerance. Moreover, by choosing NiO x as the hole-injection layer, the CE is improved to 10.15 cd A −1 and EQE is improved to a record of 3.26% for perovskite LEDs produced by vacuum deposition. The time efficient combinatorial approaches can also be applied to optimize other perovskite LEDs.
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高影响因子
ACS Applied Nano Materials
·
2019
·
IF 0
Xinling Xu,Liping Zhou,Degong Ding,Yang Wang,Jingyun Huang,Haiping He,Zhizhen Ye
Two-dimensional silicon-based materials have unique physical and chemical properties due to high surface area and quantum confinement effects. Herein, a topochemical reaction method is used for preparing silicene quantum dots confined in few layer siloxene nanosheets with FeCl3·6H2O as oxidant, which shows a thickness less than 2 nm. The experimentally prepared siloxene nanosheets are dispersible, with silicene quantum dots having an average diameter less than 5 nm. The silicene quantum dots are self-organized through the oxidation of FeCl3, showing unique optical properties of blue emission. The UV–visible absorption and PL emission spectra indicate the quasi-direct band gap transition to the emission. Besides, the few-layer siloxene nanosheets with silicene quantum dots have a radiative lifetime of 1.098 ns at an emission wavelength of 435 nm, which derives from the quasi-direct band transition of silicene quantum dots. Such two-dimensional nanosheets of silicon possess potential applications for the emitting layer materials of blue light-emitting diodes (LED).
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Nano Research
·
2019
·Vol. 13
·期 5
·1354-1362
·
IF 8.515
Jiang Nina,Li Danyang,Liang Lili,Xu Qing,Shao Lei,Wang Shi-Bin,Chen Aizheng,Wang Jianfang
We describe a route to the preparation of (metal yolk)/(porous ceria shell) nanostructures through the heterogeneous growth of ceria on porous metal nanoparticles followed by the calcination-induced shrinkage of the nanoparticles. The approach allows for the control of the ceria shell thickness, the metal yolk composition and size, which is difficult to realize through common templating approaches. The yolk/shell nanostructures with monometallic Pt and bimetallic PtAg yolks featuring plasmon-induced broadband light absorption in the visible region are rationally designed and constructed. The superior photocatalytic activities of the obtained nanostructures are demonstrated by the selective oxidation of benzyl alcohol under visible light. The excellent activities are ascribed to the synergistic effects of the metal yolk and the ceria shell on the light absorption, electron-hole separation and efficient mass transfer. Our synthesis of the (metal yolk)/(porous ceria shell) nanostructures points out a way to the creation of sophisticated heteronanostructures for high-performance photocatalysis.
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高影响因子
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