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Ye T, Sun YY, Kocherga M, Nesmelov A, Schmedake TA, Zhang Y. Degradation Kinetics of Organic-Inorganic Hybrid Materials from Micro-Raman Spectroscopy and Density-Functional Theory: The Case of β-ZnTe(en) 0.5. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2302935. [PMID: 37322314 DOI: 10.1002/smll.202302935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 05/28/2023] [Indexed: 06/17/2023]
Abstract
Organic-inorganic hybrid materials often face a stability challenge. β-ZnTe(en)0.5 , which uniquely has over 15-year real-time degradation data, is taken as a prototype structure to demonstrate an accelerated thermal aging method for assessing the intrinsic and ambient-condition long-term stability of hybrid materials. Micro-Raman spectroscopy is used to investigate the thermal degradation of β-ZnTe(en)0.5 in a protected condition and in air by monitoring the temperature dependences of the intrinsic and degradation-product Raman modes. First, to understand the intrinsic degradation mechanism, the transition state of the degradation is identified, then using a density functional theory, the intrinsic energy barrier between the transition state and ground state is calculated to be 1.70 eV, in excellent agreement with the measured thermal degradation barrier of 1.62 eV in N2 environment. Second, for the ambient-condition degradation, a reduced thermal activation barrier of 0.92 eV is obtained due to oxidation, corresponding to a projected ambient half-life of 40 years at room temperature, in general agreement with the experimental observation of no apparent degradation over 15 years. Furthermore, the study reveals a mechanism, conformation distortion enhanced stability, which plays a pivotal role in forming the high kinetic barrier, contributing greatly to the impressive long-term stability of β-ZnTe(en)0.5 .
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Affiliation(s)
- Tang Ye
- Nanoscale Science, University of North Carolina at Charlotte, Charlotte, NC, 28223, USA
| | - Yi-Yang Sun
- State Key Laboratory of High-Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 201899, China
| | - Margaret Kocherga
- Nanoscale Science, University of North Carolina at Charlotte, Charlotte, NC, 28223, USA
| | - Andrei Nesmelov
- Department of Chemistry, University of North Carolina at Charlotte, Charlotte, NC, 28223, USA
| | - Thomas A Schmedake
- Nanoscale Science, University of North Carolina at Charlotte, Charlotte, NC, 28223, USA
- Department of Chemistry, University of North Carolina at Charlotte, Charlotte, NC, 28223, USA
| | - Yong Zhang
- Nanoscale Science, University of North Carolina at Charlotte, Charlotte, NC, 28223, USA
- Department of Electrical and Computer Engineering, University of North Carolina at Charlotte, Charlotte, NC, 28223, USA
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Zhang F, Castaneda JF, Gfroerer TH, Friedman D, Zhang YH, Wanlass MW, Zhang Y. An all optical approach for comprehensive in-operando analysis of radiative and nonradiative recombination processes in GaAs double heterostructures. LIGHT, SCIENCE & APPLICATIONS 2022; 11:137. [PMID: 35562347 PMCID: PMC9106719 DOI: 10.1038/s41377-022-00833-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 04/21/2022] [Accepted: 04/29/2022] [Indexed: 05/29/2023]
Abstract
We demonstrate an all optical approach that can surprisingly offer the possibility of yielding much more information than one would expect, pertinent to the carrier recombination dynamics via both radiative and nonradiative processes when only one dominant deep defect level is present in a semiconductor material. By applying a band-defect state coupling model that explicitly treats the inter-band radiative recombination and Shockley-Read-Hall (SRH) recombination via the deep defect states on an equal footing for any defect center occupation fraction, and analyzing photoluminescence (PL) as a function of excitation density over a wide range of the excitation density (e.g., 5-6 orders in magnitude), in conjunction with Raman measurements of the LO-phonon plasmon (LOPP) coupled mode, nearly all of the key parameters relevant to the recombination processes can be obtained. They include internal quantum efficiency (IQE), minority and majority carrier density, inter-band radiative recombination rate (Wr), minority carrier nonradiative recombination rate (Wnr), defect center occupation fraction (f), defect center density (Nt), and minority and majority carrier capture cross-sections (σt and σtM). While some of this information is thought to be obtainable optically, such as IQE and the Wr/Wnr ratio, most of the other parameters are generally considered to be attainable only through electrical techniques, such as current-voltage (I-V) characteristics and deep level transient spectroscopy (DLTS). Following a procedure developed herein, this approach has been successfully applied to three GaAs double-heterostructures that exhibit two distinctly different nonradiative recombination characteristics. The method greatly enhances the usefulness of the simple PL technique to an unprecedented level, facilitating comprehensive material and device characterization without the need for any device processing.
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Affiliation(s)
- Fan Zhang
- Department of Electrical and Computer Engineering, The University of North Carolina at Charlotte, Charlotte, NC, 28223, USA
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, China
| | - Jose F Castaneda
- Department of Electrical and Computer Engineering, The University of North Carolina at Charlotte, Charlotte, NC, 28223, USA
| | | | - Daniel Friedman
- National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Yong-Hang Zhang
- School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, AZ, 85287, USA
| | | | - Yong Zhang
- Department of Electrical and Computer Engineering, The University of North Carolina at Charlotte, Charlotte, NC, 28223, USA.
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Liu X, Zhou Z, Wang T, Xu Y, Lu K, Yan Y. Molecularly imprinted polymers-captivity ZnO nanorods for sensitive and selective detecting environmental pollutant. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2020; 228:117785. [PMID: 31767418 DOI: 10.1016/j.saa.2019.117785] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 11/08/2019] [Accepted: 11/10/2019] [Indexed: 06/10/2023]
Abstract
To develop the semiconductor of ZnO nanomaterials as the fluorescence sensor without leakage toxicity. Here, a molecularly imprinted polymer captivity ZnO nanorods (NRs) (MIPs-captivity ZnO NRs) was fabricated by precipitation polymerization. Such traditional technology was not only achieved the specific recognition for direct fluorescent quantification of the target tetracycline (TC) through fluorescence quenching, but also formed the shield to reduce the toxic effects of ZnO towards organisms. Under the optimized experimental conditions, the MIPs-captivity ZnO NRs were effectively applied to the direct fluorescence quantification of TC with excellent stability. Moreover, the practical analytical performance of the MIPs-captivity ZnO NRs was assayed by appraising the detection effects of TC in water sample from the Yangtze River with satisfactory results.
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Affiliation(s)
- Xiqing Liu
- School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Zhiping Zhou
- School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Tao Wang
- Institute of Green Chemistry and Chemical Technology, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Yeqing Xu
- Institute of Green Chemistry and Chemical Technology, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Kai Lu
- Institute of Green Chemistry and Chemical Technology, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Yongsheng Yan
- Institute of Green Chemistry and Chemical Technology, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, China.
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Wang T, Liu X, Han D, Ma C, Wei M, Huo P, Yan Y. Biomass derived the V-doped carbon/Bi 2O 3 composite for efficient photocatalysts. ENVIRONMENTAL RESEARCH 2020; 182:108998. [PMID: 31863945 DOI: 10.1016/j.envres.2019.108998] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 10/29/2019] [Accepted: 12/02/2019] [Indexed: 06/10/2023]
Abstract
This work focused on the utilization of biological extract for the preparation of lignin-based carbon composites materials and used in the field of photocatalysis. A straightforward one-step carbonization way has been developed to prepare vanadium-doped lignin-based carbon/Bi2O3 composites photocatalyst by using sodium lignosulfonate as the carbon source and catalyst. The application of lignin as the carbon source to form photocatalyst support tends to control the uniform distribution. At the same time, sodium lignosulfonate as the catalyst could break down the BiVO4 during carbonization process. A series of characterizations demonstrated the BiVO4 was transformed into Bi2O3 and vanadium-doped lignin-based carbon. The possible synthesis process was proposed. Moreover, the novel V-doped carbon/Bi2O3 composites photocatalyst displayed higher photocatalytic activity than bare BiVO4. A possible photocatalytic mechanism was also discussed. This work provided new insight into the lignin-based carbon materials.
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Affiliation(s)
- Tao Wang
- School of Chemistry and Chemical Engineering, Jiangsu University, 212013, Zhenjiang, PR China; Institute of Green Chemistry and Chemical Technology, Jiangsu University, 212013, Zhenjiang, PR China
| | - Xiqing Liu
- School of Material Science and Engineering, Jiangsu University, 212013, Zhenjiang, PR China
| | - Donglai Han
- Institute of Green Chemistry and Chemical Technology, Jiangsu University, 212013, Zhenjiang, PR China
| | - Changchang Ma
- School of Chemistry and Chemical Engineering, Jiangsu University, 212013, Zhenjiang, PR China; Department of Chemistry, Dongguk University, Seoul, 04620, Republic of Korea
| | - Maobin Wei
- College of Physics, Jilin Normal University, 13600, Siping, PR China
| | - Pengwei Huo
- School of Chemistry and Chemical Engineering, Jiangsu University, 212013, Zhenjiang, PR China; Institute of Green Chemistry and Chemical Technology, Jiangsu University, 212013, Zhenjiang, PR China
| | - Yongsheng Yan
- School of Chemistry and Chemical Engineering, Jiangsu University, 212013, Zhenjiang, PR China; Institute of Green Chemistry and Chemical Technology, Jiangsu University, 212013, Zhenjiang, PR China.
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Qiu J, Qi X, Li X, Xu W, Tang Y, Ma Z. Broadband, high-resolution Raman observations from a double-echelle spatial heterodyne Raman spectrometer. APPLIED OPTICS 2018; 57:8936-8941. [PMID: 30461879 DOI: 10.1364/ao.57.008936] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 09/18/2018] [Indexed: 06/09/2023]
Abstract
A new broadband Raman spectrometer has been developed, to the best of our knowledge, using a double-echelle spatial heterodyne Raman spectrometer (DESHRS). The instrument is constructed by using two echelle gratings. Masks are used to remove the shadow ghosts caused by the different orders of the two echelle gratings. Raman spectra of inorganic solid targets and methanol are given, and Raman shifts of up to 3000 cm-1 are obtained by the DESHRS. The instrument has shown that a broadband coverage and high resolution can be achieved simultaneously to meet the requirements of Raman measurements, covering 3590 cm-1 with 1.21 cm-1 spectral resolution.
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Qiu J, Qi X, Li X, Tang Y, Lantu J, Mi X, Bayan H. Broadband transmission Raman measurements using a field-widened spatial heterodyne Raman spectrometer with mosaic grating structure. OPTICS EXPRESS 2018; 26:26106-26119. [PMID: 30469702 DOI: 10.1364/oe.26.026106] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 08/28/2018] [Indexed: 06/09/2023]
Abstract
A field-widened spatial heterodyne Raman spectrometer with a mosaic grating structure is developed for the simultaneous sensitivity enhancement and broadband transmission Raman measurements. We optimize the etendue to maximize the signals collected from the samples by using field-widening prisms and employ two mosaic gratings to achieve broadband operation, covering 5638 cm-1 with 2.865 cm-1 spectral resolution. The signal-to-noise ratios are improved by a factor of more than 11 and show a good stability and fair repeatability. We investigate the effects of the sample thickness and outer layer depth and observe liquids, solids, mixed targets, and anti-Stokes shifts. The instrument exhibits good performance for wide-field, high-resolution broadband transmission Raman measurements.
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