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Your search keyword '"Hao, Jianyuan"' showing total 183 results
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183 results on '"Hao, Jianyuan"'

19. Enhanced visible light photocatalytic performance of a novel FeIn2S4 microsphere/BiOBr nanoplate heterojunction with a Z-scheme configuration.

Author

Zhang, Biao, Liu, Yu, Zhu, Hongyu, Gu, Dongxu, Zhou, Kanghong, and Hao, Jianyuan

Subjects
HETEROJUNCTIONS, VISIBLE spectra, PHOTODEGRADATION, PHOTOCATALYSTS, RHODAMINE B, ENVIRONMENTAL remediation
Abstract

The rational design of heterojunction photocatalysts is an effective way to improve semiconductor photocatalytic activity. The simple solvothermal method was used to successfully prepare visible light-driven FeIn2S4 microsphere/BiOBr nanoplate binary heterojunction photocatalysts with varying FeIn2S4 contents. The crystal structure, morphology, surface composition, specific surface area, charge separation, and optical properties of the as-prepared photocatalysts were investigated using a variety of analytical methods. In the photocatalytic degradation of rhodamine B, the FeIn2S4/BiOBr photocatalysts obtained a degradation efficiency of 96% within 60 min, which was approximately 5.33 and 2.59 times higher than pure FeIn2S4 and BiOBr, respectively. Radical trapping experiments and ESR measurements revealed the main active species (·OH, ·O2−, and h+) produced during photocatalytic degradation. The increased photocatalytic activity was due to the formation of Z-scheme heterojunctions between FeIn2S4 and BiOBr, which contributed to the improved effective charge separation of photogenerated charge carriers, augmented specific surface area, and enhanced redox capacity. It is expected that our current study will provide a hopeful way for future environmental remediation research. [ABSTRACT FROM AUTHOR]

Published
2023
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35. Synthesis of polyethyleneimine-modified magnetic iron oxide nanoparticles without adding base and other additives

Author

Yang Li, Jinshan Xu, Jingxuan Yang, Xie Maoqiong, Yu Liu, Hui Shen, and Hao Jianyuan

Subjects
chemistry.chemical_classification, Materials science, Base (chemistry), Mechanical Engineering, Inorganic chemistry, Nanoparticle, 02 engineering and technology, Polymer, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Ph stability, 01 natural sciences, 0104 chemical sciences, chemistry.chemical_compound, chemistry, Mechanics of Materials, Molecule, General Materials Science, Crystallite, 0210 nano-technology, Iron oxide nanoparticles, Stabilizer (chemistry)
Abstract

A simple method of preparing PEI-modified magnetic iron oxide nanoparticles (Fe3−xO4@PEI) in one-step without adding base and other additives has been developed in order that pre-modified PEI molecules containing alkaline sensitive bonds can directly be used. In this method, polyethyleneimine (PEI) was selected as base as well as stabilizer and high pH value media was avoided. Different with other co-precipitation processes, Fe2+/Fe3+ 5 and N/Fe 4 were proved to be the optimal conditions. The synthesized product was confirmed to be Fe3−xO4@PEI with small crystallite size and good magnetic property, and proved to be stable at pH3–pH10. This report provides an easy way in preparation of modified magnetic iron oxide nanoparticles using polymers containing alkaline sensitive bonds.

Published
2017

37. Constructing BiOBr/g-C3N4/Bi2O2CO3 Z-scheme photocatalyst with enhanced photocatalytic activity.

Author

Zhang, Biao, Liu, Yu, Zhou, Kanghong, Zhu, Hongyu, Gu, Dongxu, Ge, Wei, Gan, Ying, and Hao, Jianyuan

Subjects
PHOTOCATALYSTS, VISIBLE spectra, LIGHT absorption, HETEROJUNCTIONS, RHODAMINE B, OPTICAL properties
Abstract

In this work, the novel camellia-structured double Z-scheme BiOBr/g-C3N4/Bi2O2CO3 was simply prepared by a hydrothermal method. XRD, FTIR, SEM, TEM, XPS, UV-DRS, and PL were used to investigate the composition, morphology, chemical condition, and optical properties of the prepared samples, respectively. The ternary heterojunction photodegraded Rhodamine B under visible light within 60 min with much higher degradation efficiency (98 %) comparing with pure BiOBr, g-C3N4, and Bi2O2CO3. Radical trapping experiments and ESR results exhibited the main reactive species (·O2− and ·OH) during the degradation process. The formation of dual Z-scheme heterojunction improved the rate of charge separation, enhanced the absorption of visible light, and thus promoted the photocatalytic activity. The BiOBr/g-C3N4/Bi2O2CO3 photocatalysts are a promising material for the removal of dye in effluents. [ABSTRACT FROM AUTHOR]

Published
2021
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39. Influence of synthesis conditions on the structure and size of magnetite nanoparticles in co-precipitation method without stabilizer in one system

Author

Xia, Maoxue, Liu, Yu, Huang, Nianhua, Zhu, Hongyu, and Hao, Jianyuan

Abstract

Unique properties of magnetite (Fe3O4) nanoparticles (MNPs) have promoted wide applications in various fields, but specifying and defining preparation conditions of MNPs are still challenges for the desired monodispersed size. We discussed systematically the influence of synthesis conditions on the structure and size of MNPs in co-precipitation method without stabilizer in one system. NH4OH/Fe3+ratio, Fe3+/Fe2+ratio, initial concentration of HCl, total concentration of iron ions, reaction temperature, aging time and washing times were investigated. The surface of magnetite crystal was easily oxidized at high NH4OH/Fe3+ratio, and the high pH value of the reaction system can induce the large crystalline size. The hydrodynamic diameter of MNPs was efficiently controlled by the equilibrium of DLVO forces and non-DLVO forces. An appropriate initial concentration of HCl and higher reaction temperature can reduce the crystalline size due to the decelerated nucleation rate. The aging time and the total concentration of iron affected the crystalline size positively. Noticeably, pH value of MNPs dispersion in distilled water would remarkably reduce after each washing by centrifugation due to surface absorption of hydroxy group. This research provided the fundamental support for the reproducible preparation of MNPs in co-precipitation method.

Published
2022
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49. Polyethyleneimine-modified magnetite prepared without a base to remove Congo red in water

Author

Liu, Yu, Gan, Ying, Zhao, Cong, Xie, Maoqiong, Gu, Dongxu, Shuai, Shirong, Zhu, Hongyu, and Hao, Jianyuan

Abstract

Polyethyleneimine-modified magnetite (Fe3O4@PEI) with excellent stability within a wide pH range in aqueous solution was synthesized by only one-step coprecipitation in the absence of other bases. PEI was used as the precipitant and the stabilizer. The preparation condition was optimized, and the role of PEI was also clarified. The crystallization process of magnetite only in the presence of PEI was different from others with ammonia solution added as a base. The adsorption behavior of Fe3O4@PEI on anionic dyes, including methyl blue, orange I and Congo red (CR), was studied. Highly efficient adsorption of CR was observed within a wide pH range (2–10). Saturated adsorption could be achieved within 10 min. The isotherm and kinetics revealed the multimolecular layer chemisorption of CR. After the fourth cycle, the adsorption efficiency of CR was still above 98%. This research provided a very simple method for removing CR in aqueous solution with high efficiency.

Published
2021
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