Search

Your search keyword '"Hu, Xuzhi"' showing total 159 results
Start Over Author "Hu, Xuzhi" Language english
159 results on '"Hu, Xuzhi"'

13. Interactions between pesticides, surfactants and plant waxes

Author

Hu, Xuzhi and Lu, Jian

Subjects
Drug delivery, Neutron reflection, Plant waxes, Nonionic surfactant, Pesticide formulation, Small angle neutron scattering
Abstract

Nonionic surfactants are normally added into commercial pesticide formulation to help enhance pesticide solubilisation, increase droplet coverage on plant surface and transport active ingredients across plant outer surfaces, the wax film. Pesticide efficiency is dominated by the interactions between pesticides, surfactants and waxes. However, our knowledge of these interactions at the molecular level still remains very limited. In the work presented in this thesis, key aspects from a typical agri-spray process were followed. The investigations focused on the configurational alterations of surfactant micelles as the pesticide nanocarriers upon pesticide and wax solubilisation, and the structural changes of the reconstituted wax films before and after exposure to pesticides and surfactants. The impact on the structural changes of surfactant micelles upon pesticide and wax solubilisation was investigated by small angle neutron scattering (SANS), cryogenic transmission electron microscopy (cryo-TEM) and nuclear magnetic resonance (NMR). By taking advantages of isotopic contrast variations, the power of NMR to locate the exact amount and positions of pesticide and wax molecules inside surfactant micelles, and the visual support form cryo-TEM images, our studies have revealed that pesticide solubilisation clearly altered micellar structures, by increasing the aggregation number and micellar length, whilst shrinking and dehydrating their shells, leading to consequent decrease in the cloud points. When waxes were further solubilised into the pesticide-loaded micelles, pesticides were partially released from the micelles, resulting in the adjustment of micellar structures by shortening their length, whilst expanding and rehydrating their shell. The thermodynamic equilibrium of pesticide and wax solubilisation in surfactant micelles can also be altered by temperature change. Increasing temperature can drive pesticides further into the micelles and solubilise more waxes. It can also affect the micellar structures by elongation in the total length, shrinkage and dehydration in the shells. The adsorption dynamics of pesticides and surfactants onto model wax films was studied using neutron reflection (NR) in combination with deuterium labelling to wax, surfactant and solvent. The wax films were reconstituted onto hydrophilic and hydrophobic surfaces, respectively. Though the wax films on both surfaces bear similar morphologies composed of top wax crystals and underlying films, which is comparable to the natural wax morphology, the structural configuration differs significantly. Compared to wax films on the hydrophilic surface, the films formed onto the hydrophobic surface are packed more tightly within the substrate. They are thus more stable and robust when exposed to pesticides and surfactants. Clearly, the hydrophobicity of the substrates influences detailed film morphology and integrity. The more stable wax films on the hydrophobic substrate enabled us to observe how surfactants adsorbed onto and penetrated into the wax films and then altered local structures of the wax films. Similar studies also enabled us to follow how pesticides diffused into the model plant waxy barrier. This work altogether has provided a useful rationalisation of interplay between surfactant structures, pesticide structures and environmental factors that affect pesticide loading and release before and after exposure to wax films.

Published
2020

24. Synergistic passivation and stepped-dimensional perovskite analogs enable high-efficiency near-infrared light-emitting diodes

Author

Liu, Yongjie, Tao, Chen, Cao, Yu, Chen, Liangyan, Wang, Shuxin, Li, Pei, Wang, Cheng, Liu, Chenwei, Ye, Feihong, Hu, Shengyong, Xiao, Meng, Gao, Zheng, Gui, Pengbing, Yao, Fang, Dong, Kailian, Li, Jiashuai, Hu, Xuzhi, Cong, Hengjiang, Jia, Shuangfeng, Wang, Ti, Wang, Jianbo, Li, Gang, Huang, Wei, Ke, Weijun, Wang, Jianpu, and Fang, Guojia

Published
2022
Full Text
View/download PDF

40. Solution fabrication methods and optimization strategies of CsPbBr3 perovskite solar cells.

Author

Chen, Chuanliang, Lu, Xiaoman, Hu, Xuzhi, Liang, Guijie, and Fang, Guojia

Abstract

In recent years, all-inorganic CsPbBr3 perovskite solar cells (PSCs) have attracted tremendous attention due to their superb stability under thermal and moisture induction. Great efforts have been made to fabricate CsPbBr3 PSCs with enhanced efficiency and stability. To date, the power conversion efficiency of CsPbBr3 PSCs has steadily increased from the initial 5.95% to the current 11.08%, demonstrating attractive potential in the photovoltaic field. In this article, we briefly review the development and current status of CsPbBr3 PSCs, summarize the solution preparation methods of CsPbBr3 films, and analyze emphatically the optimization strategies of CsPbBr3 PSCs. Finally, we discuss the potential applications and prospects of CsPbBr3 PSCs. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

42. Stability and Efficiency Enhancement of Antimony Selenosulfide Solar Cells with Inorganic SnS‐Modified Nickel Oxide Hole Transport Materials.

Author

Li, Jiashuai, Hu, Xuzhi, Zheng, Xiaolu, Gao, Zheng, Wang, Shuxin, Liu, Yongjie, Wang, Chen, Shao, Wenlong, and Fang, Guojia

Subjects
SOLAR cells, NICKEL oxide, NICKEL oxides, ANTIMONY, SURFACE preparation, ABSORPTION coefficients, ENERGY bands, SILVER sulfide
Abstract

Antimony selenosulfide (Sb2(S,Se)3) has been emerging as a promising light absorber owing to its tunable bandgap (1.1–1.7 eV), high absorption coefficient (>105 cm−1), and excellent phase and environmental stability. Lithium salt‐doped 2,2′,7,7′‐tetrakis(N,N‐di‐p‐methoxy‐phenylamine)‐9,9′‐spirobifluorene (spiro‐OMeTAD) has been generally used as the hole transport layer (HTL) in these high‐efficiency antimony selenosulfide solar cells so far. However, the lithium‐ion reactions and migration in this HTL may cause serious challenges for the stability of these solar cells. Herein, stable and low‐cost tin monosulfide (SnS) nanoparticles surface‐modified nickel oxide (NiOx) as an inorganic hole transport layer to fabricate highly efficient and stable all‐inorganic solar cells is developed. It is found that NiOx films not only demonstrate a higher conductivity but also form better energy band alignment after SnS surface treatment. Consequently, the power conversion efficiency of the full inorganic Sb2(S,Se)3 solar cells increases from 4.85% to 6.41%. Most importantly, the devices also demonstrate much improved thermal, moisture, and long‐term stabilities as compared to the solar cells with spiro‐OMeTAD hole transport layer. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

48. Low‐Dimensional 2‐thiopheneethylammonium Lead Halide Capping Layer Enables Efficient Single‐Junction Methylamine‐Free Wide‐Bandgap and Tandem Perovskite Solar Cells.

Author

Guan, Hongling, Zhang, Wenjun, Liang, Jiwei, Wang, Chen, Hu, Xuzhi, Pu, Dexing, Huang, Lishuai, Ge, Yansong, Cui, Hongsheng, Zou, Yuanrong, Fang, Guojia, and Ke, Weijun

Subjects
SOLAR cells, LEAD halides, OPEN-circuit voltage, CESIUM iodide, PEROVSKITE, LEAD iodide
Abstract

Wide‐bandgap (WBG) perovskite solar cells (PSCs) have garnered significant attention for their potential applications in tandem solar cells. However, their large open‐circuit voltage (VOC) deficit and serious photo‐induced halide segregation remain the main challenges that impede their applications. Herein, a post‐treatment strategy without thermal annealing is presented to form a 2D top layer of 2‐thiopheneethylammonium lead halide (n = 1) on WBG perovskites. This thermal annealing‐free post‐treatment method can more effectively passivate the defects of WBG methylamine (MA)‐free formamidinium/cesium lead iodide/bromide perovskite films and suppress photo‐induced perovskite phase segregation, as compared with the thermal annealing method that yields multi‐2D phases. The resulting opaque and semi‐transparent 1.66 eV‐bandgap perovskite solar cells deliver maximum power conversion efficiencies of 21.47% (a small VOC deficit of 0.43 V) and 19.11%, respectively, both of which are among the highest reports for inverted MA‐free WBG PSCs. Consequently, four‐terminal all‐perovskite tandem cells realize a remarkable efficiency of 26.64%, showing great promise for their applications in efficient multi‐junction tandem solar cells. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

50. Defects Passivation via Potassium Iodide Post‐Treatment for Antimony Selenosulfide Solar Cells with Improved Performance.

Author

Li, Jiashuai, Gao, Zheng, Hu, Xuzhi, Wang, Shuxin, Liu, Yongjie, Wang, Chen, Dong, Kailian, Zeng, Zhaofeng, Tao, Chen, and Fang, Guojia

Subjects
SOLAR cells, POTASSIUM iodide, PHOTOVOLTAIC power systems, ANTIMONY, PASSIVATION, ANTISITE defects, ABSORPTION coefficients
Abstract

Antimony selenosulfide (Sb2(S,Se)3) has been emerging as a promising light absorber in the past few years owing to tunable bandgap (1.1–1.7 eV), high absorption coefficient (>105 cm−1) and excellent phase and environmental stability. However, the efficiency of Sb2(S,Se)3 solar cells lags far behind the Shockley–Queisser limit. One of the critical obstacles originates from various extrinsic and intrinsic defects. They mostly locate in the deep energy levels and are prone to form recombination centers, inhibiting the improvement of device performance. Herein, surface post‐treatment via potassium iodide is introduced to fabricate high‐quality Sb2(S,Se)3 films and solar cells. The surface post‐treatment not only manipulates the crystal growth process to form compact films with larger grain size but also forms better band alignment and inhibits the formation of deep‐level defects antimony antisite (SbSe), thus improving the quality of heterojunction. Consequently, the resultant Sb2(S,Se)3 solar cells achieve a champion power conversion efficiency of 9.22%. This study provides a new strategy of passivating deep‐level intrinsic defects via surface post‐treatment for high‐efficiency Sb2(S,Se)3 solar cells. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results