查找使用阿拉丁产品的科研文献

0D Hybrid Cuprous Halide as an Efficient Light Emitter and X-Ray Scintillator

Na Lin,Ri-Cheng Wang,Shao-Ya Zhang,Zi-Han Lin,Xing-Yu Chen,Zi-Ning Li,Xiao-Wu Lei,Yu-Yin Wang,Cheng-Yang Yue

Despite the extraordinary X-ray scintillation performance of three-dimensional (3D) lead perovskite nanocrystals (PNCs), the serious biotoxicity of Pb 2+ and luminescent instability in water remain insurmountable obstacles for their applications in medical imaging. To address these drawbacks, herein, the study demonstrates one new lead-free zero-dimensional (0D) hybrid cuprous halide of single-crystalline [BzTPP] 2 Cu 2 I 4 (BzTPP = Benzyltriphenylphosphonium) as a satisfactory X-ray scintillator. [BzTPP] 2 Cu 2 I 4 displays broadband yellowish-green light emission with a high photoluminescent quantum yield (PLQY) of 44.2% and large Stokes shift of 167 nm upon UV light excitation. High PLQY and negligible self-absorption enable [BzTPP] 2 Cu 2 I 4 to display impressive scintillation performance excited by X-ray with a light yield of 27 706 photons MeV -1 and low detection limit of 0.352 µ Gy s −1 , surpassing typical 3D PNCs. More importantly, [BzTPP] 2 Cu 2 I 4 represents extraordinary structural and luminescent stability in water for at least one month. The excellent and stable radioluminescence performance as well as solution growth method ensure a [BzTPP] 2 Cu 2 I 4 -based screen for fine-resolution X-ray imaging with potential in radiography and inspection. This work highlights the multiple merits of low-toxicity and cost, high light yield, and long-term water-stability of 0D hybrid cuprous halides as highly desirable X-ray scintillators.

Visible-light photocatalytic membranes based on heterostructured Fe3O4-doped g-C3N4/TiO2 catalysts

Long Wang,Liu-Lin Zhao,Qin-Yuan He,Dan-Dan Shao,Shi-Peng Sun,Xue-Li Cao

BACKGROUND Desalination membranes have been widely in demand for separating dyes and salts. However, dyes are easily adsorbed on/in the membranes, deteriorating membrane performance. Coupling photocatalysis and membrane separation might be a promising strategy for efficiently alleviating membrane fouling. Aiming at the defects of single catalyst, this work constructed photocatalytic membranes based on heterostructured Fe 3 O 4 -doped g-C 3 N 4 (FeCN)/TiO 2 catalysts by successively filtrating FeCN aqueous dispersion and titanium butoxide/isopropanol solution on the hydrolyzed polyacrylonitrile substrate. RESULTS The H-bonds among TiO 2 , FeCN and substrate lead to excellent load stability of the photoresponsive layer. Due to the low-potential conduction band and high conductivity of Fe 3 O 4 and the low-potential conduction band of TiO 2 in FeCN/TiO 2 , electrons can be more easily transferred to guarantee the high separation efficiency of electrons and holes. Hence the membrane not only exhibited superior permeability (104 L m −2 h −1 bar −1 ) and dye desalting performance (Coomassie brilliant blue R250 rejection of >98.80% and NaCl rejection of <7.00%), but also displayed highly efficient and stable dye photodegradation. CONCLUSION The degradation efficiency surpassed that reported in the literature in comparable circumstances, and the recovery rate of permeability still reached 89.12% after three fouling–photodegradation cycles. This work provides new opportunities for designing high-efficiency self-cleaning membranes to solve membrane fouling based on low-cost materials. © 2023 Society of Chemical Industry (SCI).

Hierarchical assembly of AgCl@Sn-TiO2 microspheres with enhanced visible light photocatalytic performance

Ayyakannu Sundaram Ganeshraja,Kaixin Zhu,Kiyoshi Nomura,Junhu Wang

The hierarchical silver chloride loaded tin-doped titania (AgCl@Sn-TiO 2 ) microspheres were first time prepared by a hydrothermal method and annealing at different temperatures. The catalyst showed the enhanced visible light photocatalytic activity as compared to the plasmonic photocatalysts of AgCl and Ag/AgCl, and commercial Degussa P25 (TiO 2 ). The improved efficiency is considered to local surface plasmonic resonance (AgCl could reduce to Ag 0 during photocatalytic reaction) in enhanced broad band visible light absorption in addition to the characteristics of heterojunction between Sn-TiO 2 and AgCl NPs. Moreover, the surface and bulk properties of as-synthesized samples were analyzed by 119 Sn Mössbauer spectroscopy. The magnetic property of the bulk was studied as a function of magnetic field with different temperatures. These results signify the clear details of the magnetic and visible light photocatalytic activities of hierarchical AgCl@Sn-TiO 2 microspheres.

Enhanced visible light photocatalytic properties of Fe2O3-doped carbon nitride-based organo-catalysts

Muhammad Wasim Khan,Sana Ullah Asif,Fahim Ahmed,Ata-ur Rehman,A R Makhdoom,Ehsan Ullah Khan

Fe2O3/g-CN heterojunction composites were successfully fabricated by a simple calcinations method using iron chloride and urea as precursors. A specific amount of Fe2O3 was incorporated on the surface of g-CN and calcinated at 400, 450, and 500 °C to obtain series of Fe2O3/g-CN (400(1), 450(2), 500(3) °C) composites. Characterization techniques were applied to measure the optical activities of Fe/CNx composites. The Fe/CN(2) sample showed a significant enhancement in the separation of photo-generated carriers under visible light due to the Fe coordination within g-CN. The composites were utilized for the first time along with parent g-CN sample for the evolution of H2 source by water splitting experiment, as well as and for photodegradation of MB under visible light illumination (λ = 420 nm). Results demonstrate that Fe/CN(2) samples exhibit a remarkable photocatalytic performance in both electron generation (HER) and holes formation, i.e. good degradation performance and as such, the corresponding degradation rate of the superior sample is 91.4 % at 60 min. Moreover, the reusability tests of Fe/CNx composites at different temperatures confirm good degradation performance and have excellent photochemical stability in terms of hydrogen evolution and removal of pollutants, respectively. With experimental results, a possible photocatalytic mechanism of Fe/CN(2) composite has been exceeded to describe the whole phenomena of photocatalysis.

High-Radiance Near-Infrared Perovskite Light-Emitting Diodes with Improved Roll-Off Degradation

Maotao Yu,Yongqiang Ji,Haoming Yan,Jinhao Hu,Shunde Li,Hongyu Xu,Peng Chen,Lichen Zhao,Shuzhen Guan,Xiaoyin Bi,Xiaoyu Yang,Shuang Jia,Chang Yi,Deying Luo,Jianpu Wang,Zheng-Hong Lu,Qihuang Gong,Rui Zhu

The external quantum efficiency (EQE) of state-of-the-art near-infrared perovskite light-emitting diodes (PeLEDs) is now approaching the limit set by the out-coupling efficiency. However, there is plenty of room for enhancing these devices’ radiance and the EQE roll-off. This work reports how conductive and passivating additives construct efficient high-radiance near-infrared PeLEDs with improved EQE roll-off. Specifically, the synergistic effect of 1,4-phenylenediacetic acid (PDA) and 5-aminovaleric acid (5-AVA) is used to regulate the quality of the perovskite emissive layer, thereby enhancing the roll-off threshold of injection currents (a value at which the device EQE or radiance starts degrading). According to in situ structural evolution analyses from the perovskite precursor to the perovskite crystal, the presence of PDA within the perovskite precursor solution can produce an intermediate phase with 5-AVA and formanmidinium cation, which can retard the perovskite nucleation and crystal growth, leading to improved perovskite film quality. The resulting champion PeLED delivers among the highest radiance of 505 W sr −1 m −2 and a peak EQE of 17.56%. More importantly, the improved PeLED shows a well-retained radiance of 80% at a current injection density of up to ≈1800 mA cm −1 , opening a new avenue for high-radiance PeLEDs with improved roll-off degradation.

Photoluminescent properties of single-phase white-light Ca8ZnGd(PO4)7:Eu2+,Mn2+ phosphor

Xiaoya Bu,Yan-gai Liu,Baochen Wang,Ruiyu Mi,Ziyao Wang,Zhaohui Huang

The Eu 2+ activated Ca 8 ZnGd(PO 4 ) 7 :Eu 2+ green light emitting phosphors and Eu 2+ /Mn 2+ co-doped tunable light emitting phosphors Ca 8 ZnGd(PO 4 ) 7 :Eu 2+ ,Mn 2+ were successfully synthesized via the solid-state reaction method. The X-ray powder diffraction measurements and Rietveld refinement were used to assess the phase composite and crystal structure. The photoluminescence properties, diffuse reflection spectrum, chromaticity coordinates and fluorescence decay curves of the samples were investigated. It has been confirmed that the resonant type Eu 2+ →Mn 2+ energy transfer occurs via a dipole-quadrupole interaction. With various Eu 2+ /Mn 2+ molar ratios, the spectrum-tunable phosphors are obtained from green (0.183, 0.335) to white (0.297, 0.298).

Laser-Driven White Light Source With High Luminescence Saturation Through Reflective Color Converter

Jiuzhou Zhao,Ziyan Guo,Zikang Yu,Hongjin Zhang,Qing Wang,Yun Mou,Yang Peng

A one-dimensional dual emissive hybrid perovskite with flexibly tunable white-light emission

Dong Li,Wentao Wu,Sasa Wang,Xinyuan Zhang,Lina Li,Yunpeng Yao,Yu Peng,Junhua Luo

White-light emissive hybrid perovskites have received continuous attention because of their potential applications in solid-state lighting and displays. However, there have been limited reports about dual-emissive white-light hybrid perovskites, although they enable a wide range of emission switching. Here, we report a one-dimensional hybrid perovskite, (N-AEP)2Pb2Cl10·H2O (NAPC, N-AEP = 1-piperazineethylammonium), which exhibits dual-emissive photoluminescence with a wide emission switch ranging from blue to orange. Significantly, tunable white-light emission from “cold” white light (0.25, 0.29) to “warm” white light (0.40, 0.42) can be easily observed by finely tuning the excitation wavelength. Under excitation at 335 nm, a “cold” white light with chromaticity coordinates (0.31, 0.33) close to those of “optimal” white light (0.33, 0.33) is achieved. Furthermore, NAPC exhibits a color rendering index reaching 93.4, which is among the highest values currently reported from white-light emissive hybrid perovskites. This work paves a way to tune the photophysical properties of hybrid perovskites, and highlights their potential for solid-state lighting applications.

p-BiOI/n-SnS2 heterojunction flowerlike structure with enhanced visible-light photocatalytic performance

Tingting Wang,Hui Meng,Xiang Yu,Yizhu Liu,Hongbin Chen,Yi Zhu,Jinpeng Tang,Yexiang Tong,Yuanming Zhang

A BiOI/SnS2 p–n junction is prepared by depositing BiOI particles on flowerlike SnS2 flakes. The heterojunction formed between p-type BiOI and n-type SnS2 brings greatly improved photocatalytic activity compared with pure SnS2 or BiOI in the degradation of Rhodamine B dye under visible light and sunlight irradiation. The improved photocatalytic performance is explained by the synergetic effects of the formation of a p–n junction between BiOI and SnS2. The migration of photogenerated carriers can be promoted by the electric field established at the heterojunction interfaces, leading to effective separation of the photogenerated electron–hole pairs and reduced electron–hole recombination. The BiOI/SnS2 heterojunction will find promising applications in photocatalysis and solar energy conversion.

A printed aluminum cathode with low sintering temperature for organic light-emitting diodes

Fei Fei,Jinyong Zhuang,Weichen Wu,Minshun Song,Dongyu Zhang,Sen Li,Wenming Su,Zheng Cui

A printed aluminum cathode with low sintering temperature has been achieved using an aluminum precursor ink, AlH3·O(C3H7)2, which in the presence of a TiCl4 catalyst can be printed to give the required pattern and then sintered at 80 °C for 30 s to form an Al film. The Al cathode of 50 nm thickness has a sheet resistance of 2.09 Ω □−1 and work function of 3.67 eV. The study demonstrates that the low sintering temperature and work function of the printed film, together with its high conductivity and stability, mean that it is well suited for use as an OLED cathode and that it paves the way for fully printed flexible devices.

Efficient Inorganic Perovskite Light-Emitting Diodes with Polyethylene Glycol Passivated Ultrathin CsPbBr3 Films

Li Song,Xiaoyang Guo,Yongsheng Hu,Ying Lv,Jie Lin,Zheqin Liu,Yi Fan,Xingyuan Liu

Efficient inorganic perovskite light-emitting diodes (PeLEDs) with an ultrathin perovskite emission layer (∼30 nm) were realized by doping Lewis base polyethylene glycol (PEG) into CsPbBr3 films. PEG in the perovskite films not only physically fills the crystal boundaries but also interacts with the perovskite crystals to passivate the crystal grains, reduce nonradiative recombination, and ensure efficient luminance and high efficiency. As a result, promoted brightness, current efficiency (CE), and external quantum efficiency (EQE) were achieved. The nonradiative decay rate of the PEG:CsPbBr3 composite film is 1 order of magnitude less than that of the neat CsPbBr3 film. After further optimization of the molar ratio between CsBr and PbBr2, a peak CE of 19 cd/A, a maximum EQE of 5.34%, and a maximum brightness of 36600 cd/m2 were achieved, demonstrating the interaction between PEG and the precursors. The results are expected to offer some helpful implications in optimizing the polymer-assisted PeLEDs with ultrathin emission layers, which might have potential application in see-through displays.

One-dimensional core-shell Zn0.1Cd0.9S/Snln4S8 heterojunction for enhanced visible light photocatalytic degradation

Yunxiang Tang,Xin Zhang,Yuxue Ma,Xiaotong Wang,Changhua Su,Dafeng Zhang,Xipeng Pu,Yanling Geng

Efficient separation of photogenerated charge carriers is vitally significant in the photocatalytic reaction process. In this work, a novel Zn 0.1 Cd 0.9 S/Snln 4 S 8 (ZCS/SIS) core-shell nanorods photocatalyst was prepared by a facile solvothermal method. The photocatalytic activity of the as-synthesized samples were evaluated by the degradation of Rhodamine B (RhB) and imidacloprid (IM) under visible light irradiation. Compared with the pristine ZCS and SIS, the core-shell composites displayed dramatically improved photocatalytic activity. The apparent rate constants of RhB and IM photodegradation over ZCS/SIS are 5.07 and 16.9 time higher than that of pure ZCS, respectively. In addition, the electrochemical measurements indicate that the charge carriers separation in ZCS/SIS core-shell composites is enhanced. The reason could be the formation of the core-shell ZCS/SIS heterojunction boosting the charge carriers separation and transfer. Besides, a possible photocatalytic mechanism was proposed.