查找使用阿拉丁产品的科研文献

Surface-engineered oxidized two-dimensional Sb for efficient visible light-driven N2 fixation

Zhenqing Zhao,Changhyeok Choi,Song Hong,Huidong Shen,Chao Yan,Justus Masa,Yousung Jung,Jieshan Qiu,Zhenyu Sun

Solar N 2 fixation under visible light offers a promising method toward sustainable NH 3 production at benign conditions. However, it still remains a formidable challenge to activate and cleave N N bonds and promote the separation and transport of electrons and holes during photocatalysis . To address these issues, the discovery and design of high-performance and robust photocatalysts is imperative. Here, we report the defect engineering of two-dimensional oxidized Sb nanosheets to activate intrinsically inactive Sb for efficient visible light-driven N 2 reduction to NH 3 . Impressively, the Sb nanosheets rich in Sb and oxygen vacancies afford a remarkable NH 3 formation rate of up to 388.5 μg NH3 h −1 g cat. −1 without cocatalyst in visible light, 8 times higher than that for bulk Sb and also significantly outperforming many previously reported photocatalysts. The defective Sb nanosheets exhibit excellent stability after five successive reaction cycles. Further density functional theory calculations reveal a considerably strong interaction between N 2 and defects on the surface and edge of Sb nanosheets , which facilitates the formation of *NNH (N 2  + (H +  +  e - ) → *NNH, where * denotes an adsorption site), thus promoting photocatalytic N 2 reduction. This finding opens a novel avenue to enhancing N 2 photofixation over inherently inactive surfaces by synergistically engineering defect sites.

Photothermal Optimization of Quantum Dot Converters for High-Power Solid-State Light Sources

Jiexin Li,Zongtao Li,Jiayong Qiu,Jiasheng Li

Quantum dots (QDs) exhibit remarkable photoelectric performance. However, the conversion efficiency and thermal performance of QD converters so far is not satisfactory for high-power solid-state light (SSL) applications owing to the serious reabsorption loss of QDs and the poor thermal diffusion of polymer materials. Here, an efficient QD converter based on an anodic aluminum membrane (AAM), with high light enhancement and thermal diffusion, is introduced for high-power SSL applications. Nanoporous AAMs are utilized as templates for confining the QD deposition into the nanowire (NW) shape by incorporating inkjet printing and vacuum-deposition methods, forming vertical QD NW arrays. Compared with conventional converters, QD-AAM yields nearly twofold photoluminescence intensity. Three-dimensional finite-difference (FDTD) simulations attribute the fluorescence-enhancement mechanism to the enhancement of QD conversions and boosting of the waveguide effect in QD-AAM. Furthermore, QD-AAM exhibits excellent thermal diffusion performance under high-power excitation, owing to the inner heat conduction path in the AAM framework. This study provides a practical and efficient strategy to comprehensively enhance the optical and thermal performance of QD converters for high-power SSL applications.

Effect of ion migration on lead halide perovskite on visible light communication system

Haocheng Tang,Yichi Zhong,Jingzhou Li,Luyang Hou,Xizhe Liang,Jiahao Zhang,Hongyu Yang,Hongxing Dong,Long Zhang

Benefiting from the high modulation bandwidth (BW), low energy consumption and excellent optical performance, lead halide perovskite has attracted wide attention in visible light communication (VLC). However, the ion migration which results in mobile point defects in perovskite structures is recognized as a crucial key factor inducing the performance degradation. Here, the influence of ion migration in perovskite devices on the performance of VLC was systematically studied. The ion migration process is realized by mixing CsPbBr 3 and CsPbI 3 quantum dots, during which, the performance of the VLC system is reduced, but it can return to its initial state after stabilization. The on-off keying (OOK) modulation scheme of the perovskite light-emitting diode (LED) device was carried out, achieving a data rate of 90 Mbps.

Development and evaluation of Al2O3–ZrO2 composite processed by digital light 3D printing

Tianqi Zheng,Wei Wang,Jinxing Sun,Jing Liu,Jiaming Bai

Digital Light Processing (DLP) is a promising approach to fabricate delicate ceramic components with high-fidelity structural features. In this work, the alumina and zirconia/alumina ceramic suspensions with low viscosity and high solid loading (40 vol%) were prepared specifically for DLP 3D printing . After debinding and sintering, the final parts were obtained without any defects. The surface morphologies and mechanical properties of alumina (Al 2 O 3 ) and zirconia toughened alumina (ZTA) composites were investigated and the results showed that the final parts exhibited high relative densities and good interlayer combination at the sintering temperature of 1600 °C. Comparing with the Al 2 O 3 , the ZTA composites exhibited significantly enhanced density (99.4%), bending strength (516.7 MPa) and indentation fracture toughness (7.76 MPa m 1/2 ).

Efficient activation of persulfate by C@Fe3O4 in visible-light for tetracycline degradation

He Zhang,Yu Mei,Fang Zhu,Fenting Yu,Sridhar Komarneni,Jianfeng Ma

A C@Fe 3 O 4 material, Fe 3 O 4 coated with carbon, was prepared by a simple one-pot hydrothermal method . The C@Fe 3 O 4 material was investigated with persulfate (PS) and light to degrade tetracycline (TC) as a function of pH, aeration conditions and quenching. Experimental results suggest that TC was effectively degraded in the C@Fe 3 O 4 /PS/Vis system. In addition, due to the availability of different main active species in this catalytic system, TC degradation was possible under both strong acid and strong alkali pH conditions. The presence of dissolved oxygen can also generate oxygen-active species, such as superoxide radicals (O 2 • - ) and singlet oxygen ( 1 O 2 ), to decompose TC organic matter in solution. Simply put, C@Fe 3 O 4 /PS/Vis catalytic system removed pollutants by the formation of O 2 • - , 1 O 2 , hydroxyl radicals (•OH) and sulfate radicals (SO 4 • - ) species for degrading TC. In addition, the stability of the C@Fe 3 O 4 material was found to be outstanding.

Fabrication of novel BiVO4/Bi2O3 heterostructure with superior visible light induced photocatalytic properties

Maira Liaqat,Khalid Nadeem Riaz,Tahir Iqbal,Ghulam Nabi,Muhammad Rizwan,M Shakil

Heterostructure BiVO4/Bi2O3 nanocomposites with enhanced visible light activity are effectively synthesized through an easiest and single step hydrothermal route, using bismuth subnitrate and ammonium meta-vanadate as main raw materials in existence of citric acid. The phase and surface structure, topography and optical properties of synthesized composites are characterized by XRD, SEM, EDX, FTIR, UV–Visible and PL spectroscopy. It was found that 5%BiVO4/Bi2O3 (BOBV-5) nanocomposite exhibit excellent photocatalytic performance for rhodamine B dye degradation and tetracyclic under irradiation of visible light as compared to single component i.e. BiVO4. The increased photocatalytic activity should be ascribed for making p–n heterojunction among p-type Bi2O3 and n-type BiVO4. This p–n heterojunction successfully reduce the recombination of photogenerated charge carriers. Furthermore, the BOBV-5 novel photocatalyst shows good stability in constructive five cycles and photocatalytic activity is best for conquering photo corrosion of a photocatalysts. To explain charge migration route, whole photocatalytic mechanism was described in terms of energy band structures. Furthermore, the present work is helpful effort for design of new visible light photocatalytic materials with heterojunction structures.

Photochemical Activity of Black Phosphorus for Near-Infrared Light Controlled In Situ Biomineralization

Jundong Shao,Changshun Ruan,Hanhan Xie,Paul K. Chu,Xue-Feng Yu

The photochemical activity of black phosphorus (BP) in near-infrared (NIR) light controlled in situ biomineralization is investigated. Owing to the excellent NIR absorption, irradiation with NIR light not only promotes degradation of BP into PO 4 3− , but also enhances the chemical activity to accelerate the reaction between PO 4 3− and Ca 2+ and promote in situ biomineralization. Mineralization of hydrogels is demonstrated by the preparation of BP incorporated hydrogel (BP@Hydrogel) which delivers greatly improved biomineralization performance under NIR illumination. The biomineralization process which can be controlled by modulating the light irradiation time and location has a high potential in controlling the mechanical properties and osteoinductive ability in tissue engineering. This study also provides insights into the degradation, photochemical activity, and new biological/biomedical applications of BP.

Fabrication of PSCs with light absorption chips utilizing double-metal-cladding waveguide technology

Yutian Liu,Junjie Yang,Yanbin Chen,Qianliu Yin,Rui Shen,Zixiang Dai,Qianyi Jiao,Zhicheng Sui,Tian Xu

Metal nanoparticles or periodic metal nanostructures exhibit localized surface plasmon resonance (LSPR) effects, widely employed in photovoltaic devices to enhance the light absorption. In this study, we used a double-metal-cladding waveguide (DMCW) structure to fabricate hexagonal metal nanostructures on the front side of the indium tin oxide (ITO) glass, positioned away from the incident light direction. We then prepared perovskite solar cells under various reaction conditions. The analysis results indicate that the metal nanostructure chip excites near-field coupling, generating strong localized fields, and enhances the light absorption through the LSPR effect. The perovskite solar cells (PSCs) with the chip structures exhibited a significant increase in short-circuit current density (${\rm J}_{\rm SC}$) and fill factor (FF), accompanied by a decrease in dark current, indicating improved photovoltaic characteristics of the cells. Altering the evaporative deposition time of the silver film and the concentration of the reaction solution led to a 12.79% increase in the power conversion efficiency (PCE) of the PSCs.

DyPO4·1.5H2O Microcrystals: Microwave/Ultrasound/ Ultraviolet Light-Assisted Synthesis, Characterization and Formation Mechanism

Li Mengmeng,Huang Shuang,Zhang Hang,Wang Lei,Zhong Shengliang

Background: Researchers have pursued the new synthesis method. As a newly developed method, microwave (MW), ultrasound (US) and ultraviolet light (UV) assisted synthesis has drawn increasing interests. Under the synergistic effect, many materials with new structure, morphology and properties may be found. As an important rare-earth phosphate, DyPO4 was selected and the effect of MW, US and UV on the preparation was investigated. Methods: The DyPO4·1.5H2O nanostructures were prepared by MW, US, UV and their combination. Results: Hexagonal DyPO4·1.5H2O microcrystals obtained under MW irradiation were broomstick bundles. Needle-shaped products were formed in the presence of MW and US. Interestingly, the broom-sheaf-like structures can self-assemble into flower-shaped structures upon the irradiation of MW and UV. Whereas, MW/UV/US synergetic heating results in mixed morphologies of flower-like and needle-shaped structures. Conclusion: The growth of DyPO4 nanostructures can be tuned by selecting the combination of heating method of MW, US and UV.

Bi2WO6/UiO-NH2-66 heterojunction photocatalysts with enhanced visible light organic pollutants removal

Chen Junnan,Lin Wensong,Mai Xin,Yang Qian

In this work, the flower-like hierarchical Bi 2 WO 6 decorated with nano UiO-NH 2 -66 was fabricated by a two-step solvothermal method. The structure, composition, and morphology of the composites were characterized by XRD, FTIR, XPS, BET, and SEM. The photoelectrochemical properties of the composites were analyzed by transient photocurrent response, DRS, and PL spectra. It is found that hole (·h + ) plays a dominant role, and the hydroxyl radical (·OH) and superoxide radical (·O 2 − ) play a secondary role in the catalytic system after free radical trapping experiments. The results of electron spin resonance spin-trapping tests also confirm the mechanism. Compared with pure Bi 2 WO 6 or pure UiO-NH 2 -66, Bi 2 WO 6 /UiO-NH 2 -66 composites have much higher decomposition effectiveness of Rhodamine B under the same conditions. Furthermore, Bi 2 WO 6 /UiO-NH 2 -66 photocatalyst with 7 wt% of UiO-NH 2 -66 (denoted as BWO/UNH-7) kept the stable catalytic performance after five recycles, which may be used as a good photocatalyst for degrading organic matter in sewage. Graphical abstract

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.