Journal of Applied Spectroscopy
·
2023
·Vol. 90
·期 4
·883-892
·
IF 0.7
Shi Ying,Guo Ya-Dan,Mi Yi-Duo,Cheng Jia,Dong Wen,Zhang Gao-Feng,Zeng Yi
The antioxidant activities of flavonoid mixtures can be used to investigate the synergistic antioxidant mechanism of flavonoids. The antioxidant capacities of three flavonoids (quercetin, baicalein, and daidzein) and β-carotene in binary and ternary mixtures with kaempferol were analyzed using a 2,2-diphenyl-1-picrylhydrazyl (DPPH) inhibition assay by means of absorption spectroscopy. The results showed that the number of hydroxyl groups and o-hydroxyl groups had a significant effect on the antioxidant activity of the flavonoids, and the mixture of kaempferol, quercetin, and baicalein showed optimal synergistic antioxidant activity. Compared with quercetin and baicalein, kaempferol had the fastest inhibition rate, and multiple prolonged kinetic processes associated with the scavenging of DPPH radicals occurred in mixtures of kaempferol with the other flavonoids and β-carotene. Kaempferol has a potential synergistic antioxidant effect when mixed with daidzein and β-carotene, and the results suggested that this may be due to the regeneration of kaempferol after antioxidation. By means of classic UV-Vis spectroscopy, reaction details of the synergistic antioxidant process of DPPH radical scavenging by flavonoids can be obtained.
✓ 已验证
DOI
高影响因子
JOURNAL OF SUPERCRITICAL FLUIDS
·
2023
·
IF 3.9
Wei Guo,Ben Li,Haijun Chi,Zhongliang Jiang,Liu Qing Wei,Edward D. Ramsey
Two flow selection interfaces have been developed for connecting single or linked reactors with on-line SFC equipped with UV/Vis diode-array (DAD) and mass spectrometer detectors coupled in series (SFC-DAD-MS). This process analytical technology system, enabled the study of reactions performed in supercritical fluid carbon dioxide (SF-CO 2 ). Each interface is designed to obtain on-line samples at different reaction progress points. Three single stage electrophilic annulation reactions performed in SF-CO 2 using aniline, indole and pyrrole as amine reactants to synthesize N-heterocyclic products within a stirred continuous flow reaction vessel containing montmorillonite K-10 catalyst were monitored. Also, both stages of a two step synthetic procedure conducted within two connected continuous flow reaction coil systems were monitored using on-line SFC-DAD-MS. The first step involved a Knoevenagel reaction in SF-CO 2 that provided a continuous feed to perform a second stage acetylation reaction. Use of on-line SFC-DAD-MS enabled early detection and characterization of unexpected by-products.
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Mingjia Zhang,Shule Zhang,Fanyu Meng,Mengjie Hu,Zhongyu Wang,Yiqing Zeng,Qin Zhong
Promoting the formation of Ti-OOH in the TiO 2 -based-catalyst/H 2 O 2 /O 3 system is critical to further develop the catalytic peroxone process for low-temperature flue gas denitration. In this study, a series of phosphorus-doped TiO 2 with rich Lewis acid sites and high stability was designed and established, achieving 94 % NO oxidation efficiency with less oxidant (373 K, H 2 O 2 /NO = 1.2, O 3 /NO = 0.5) and high GHSV (1.2 × 10 5 h −1 ). Combining characterizations and DFT results, a possible mechanism was proposed: phosphorus-doping enhanced the Lewis acidity, which was conducive to the adsorption and activation of H 2 O 2 . Moreover, P-TiO 2 significantly promoted the H 2 O dissociation and Ti-OOH formation process by reducing the energy barrier, thereby promoting the synergistic effect between O 3 and Ti-OOH. The semi-in-situ UV–vis DRS demonstrated that the catalytic peroxone process occurs at the solid–liquid interface and the Ti-OOH is consumed in the catalytic process. We hope this work provide a new investigation method and insight into the catalyst design.
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2024
·
IF 4
Qifeng Chen,Yu Yao,Shuo Zheng,Qianhong Shen,Libei Jiang,Qinhua Fang,Hui Yang
A novel Yb 3+ /Er 3+ co-doped BiOBr photocatalyst with 3D flowerlike hierarchical architectures were successfully fabricated through self-assembled process without any templates under hydrothermal conditions, and the structure and properties of the photocatalysts were characterized. The results indicate that Yb 3+ ions and Er 3+ ions are successfully doped into the lattice of BiOBr, and the as-obtained photocatalyst can respond the NIR light and emit red and green light due to the up-conversion effect of the rare-earth ions. Meanwhile, with co-doped Yb 3+ /Er 3+ ions content increasing, oxygen vacancy concentration in the photocatalyst rises. The oxygen vacancy will form the intermediate energy band, which can decrease the photon energy required for electronical transition, and thus help to utilize the luminous energy generated by up-conversion luminescence. Moreover, the appropriate introduction of defects (oxygen vacancy defect and impurity atom) can further promote the transfer and separation efficiency of photo-generated carriers. Hence, Yb 3+ /Er 3+ co-doped BiOBr photocatalyst exhibits enhanced photocatalytic properties under broad spectrum (UV/vis/NIR) excitation, which is about 4 times as high as that of pure BiOBr.
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2020
·
IF 6.182
Ning Li,Xueyun Gao,Haikuan Fan,Yangqin Gao,Lei Ge
Effective and suitable utilization of solar energy was achieved using a full-spectrum-response photocatalyst AgBr/Cs x WO 3 , applied in the photocatalytic and photochromic field. Benefitting from near-infrared (NIR) absorption ability of Cs x WO 3 , AgBr/Cs x WO 3 exhibits enhanced visible-near-infrared (Vis-NIR) driven photocatalytic activity. Based on X-ray photoelectron spectroscopy (XPS), photoluminescence spectra (PL), and the photoelectrochemical analysis, AgBr and Cs x WO 3 formed a Z-scheme system at the interface to efficiently separate and transfer photo-induced electrons at a fast rate. The quenching experiment and the electron spin resonance (ESR) tests indicated that the photocatalytic reaction is activated by the production of superoxide radicals. Furthermore, the photochromic analysis to different light exhibits the AgBr/Cs x WO 3 heterostructure is stable under visible light with negligible photodeposition of AgBr, and has excellent double photochromic activity with visible-shielding effect of AgBr to Ag 0 and infrared-blocking effect of Cs x WO 3 under ultraviolet light. This research provides new insights into the manufacture of energy-efficient and environmentally friendly materials that provide excellent performance in both thermal insulation and decontamination.
✓ 已验证
DOI
高影响因子
FOOD CHEMISTRY
·
2025
·
IF 9.8
Jing Feng,Sheng Yao,Xiaohan Mei,Jiacheng Xie,Xujie Wang,Huitian Zhi,Ruhui Shang,Yingchao Yang,Lei Hu,Zhengquan Yan
To conveniently monitor and remove toxic Hg 2+ and S 2− in food samples, Au Ag quantum-dot nanozyme (Au-Ag@FA QDs) was identified. The strong synergistic effect among folic acid (FA), Ag and Au endowed Au-Ag@FA QDs with superior peroxidase-mimic activity to accelerate 3,3′,5,5′-tetramethylbenzidine (TMB) redox with K m / V max of 0.28 mmol·L −1 /6.40 × 10 −8 mol·L −1 ·s −1 . Trace Hg 2+ or S 2− could selectively alter its peroxidase-like activity and inherent fluorescence performance, with obvious hyperchromic/“turn-on” fluorescent effect for Hg 2+ or hypochromic/“turn-off” one for S 2− . And red-green-blue (RGB) values analyzed from smartphones changed regularly with c Hg 2+ or c S 2− . Under the optimized conditions, Au-Ag@FA QDs were successfully applied for multi-mode UV–vis, fluorescent, and RGB monitoring of Hg 2+ or S 2− in food samples. The detection limits were 7.38 × 10 −7 /5.74 × 10 −8 /4.93 × 10 −6 g·L −1 and 1.99 × 10 −6 /4.48 × 10 −8 /5.79 × 10 −6 g·L −1 respectively. Importantly, over 93.8 % Hg 2+ or 90.5 % S 2− could be removed by simple centrifugal-separation after detection. The selective recognition mechanisms to Hg 2+ and S 2− were also proposed.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 7
·1-11
·
IF 5.479
Xing Xinxin,Yang Yue,Zou Tong,Wang Zhezhe,Wang Zidong,Zhao Rongjun,Zhang Xu,Wang Yude
Thioglycolic acid-functionalized ZnSe quantum dots (QDs) as a colorimetric nanoprobe were prepared and applied to the determination of cobalt(II) and iron(III). Test strips were obtained by a dipping-drying process. On exposure to Co(II), they undergo a color change from white to brown, and on exposure to Fe(III) from white to pink. The limits of detection (LOD) are 2.6 mg L −1 for Co(II) and 2.2 mg L −1 for Fe(III). Test strips introduce a low-cost, portable, rapid and convenient tool for determination of Co(II) and Fe(III). In addition, two other analytical methods have been studied for detection of Co(II) and Fe(III) at low concentration. The first is UV-vis spectrometry which has a LOD as low as 0.14 mg L −1 for Co(II) (at 412 nm) and 0.12 mg L −1 for Fe(III) (at 400 nm). The second is dynamic light scattering (DLS) with a LOD of 3.0 μg L −1 for Co(II) and 2.5 μg L −1 for Fe(III).
Thioglycolic acid-functionalized ZnSe quantum dots (TGA-ZnSe QDs) show high sensitivity and low detection limits for Co 2+ and Fe 3+ .
✓ 已验证
DOI
高影响因子
Materials Science & Engineering C-Materials for Biological Applications
·
2019
·
IF 4.959
Zhu Mengting,Tonni Agustiono Kurniawan,You Yanping,Ram Avtar,Mohd Hafiz Dzarfan Othman
Bisphenol A (BPA) is a refractory pollutant presents in water body that possesses serious threats to living organisms. To deal with it, we investigate and evaluate the effectiveness of GO@BiOI/Bi 2 WO 6 composite as a novel photocatalyst for BPA removal from aqueous solutions under UV–vis irradiation. To enhance its removal for BPA, the surface of BiOI/Bi 2 WO 6 is modified with graphene oxide (GO). This composite is named as ‘GO@BiOI/Bi 2 WO 6 ’. Changes in its physico-chemical properties after surface modification with GO are characterized by XRD, FTIR, FESEM-EDS, XPS, PL, and BET methods. Optimized conditions of BPA degradation by the composite are determined under identical conditions. Photodegradation pathways of BPA and its removal mechanisms by the same composite are presented. It is obvious that the GO@BiOI/Bi 2 WO 6 has demonstrated its potential as a promising photocatalyst for BPA removal under UV–vis irradiation. About 81% of BPA removal is attained by the GO@BiOI/Bi 2 WO 6 under optimized conditions (10 mg/L of BPA, 0.5 g/L of dose, pH 7 and 5 h of reaction time). The oxidation by-products of BPA degradation include p -hydroquinone or 4-(1-hydroxy-1-methyl-ethyl)-phenol. In spite of its performance, the treated effluents are still unable to meet the maximum discharge limit of <1 mg/L set by national legislation. Therefore, subsequent biological processes are essential to maximize its biodegradation in the wastewater samples before their discharge into waterbody.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CELLULOSE
·
2025
·
IF 4.8
Zhou Yang,Zhang Sheng,Yu Kun,Yang Ming,Wang Shu,Li Qing
With development of hyperspectral imaging technology, to detect and capture detailed spectral information of a hidden object become possible. So far cotton camouflage is mostly achieved through coating or dyeing with synthetic dyes. While natural dye has gained massive popularity in recent years, its application in camouflage dyeing seems to have received little attention. This paper reports cotton cellulose as natural substrate and its dyeing with biomimetic composite natural dye of sodium copper chlorophyllin (SCC) and red onion skin extracts, to mimic reflectance curve of natural green leaves in the ultraviolet, visible and near-infrared (UV-Vis-NIR) regions. Cotton was cationically modified to enhance natural dye affinity and to improve color fastness of dyed fabrics. Results showed that at SCC concentration of 20% owf and red onion skin extracts of 80% wt, spectral correlation coefficient of dyed cotton and natural green leaves reached 0.96 in 300–1300 nm range, and colorimetric values of dyed cotton closely matched that of the standard dark green with a color difference of 3.2. The dyed cotton exhibits superior colorfastness, excellent ultraviolet protection and antioxidant capacities. The process employed in this work is simple, effective and environmentally friendly. Outcomes of this study have opened up new possibilities for the development of natural green camouflage materials with multifunctions.
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Xiaoguang Qiao,Qianqian Hao,Meng Chen,Ge Shi,Yanjie He,Xinchang Pang
The utilizing light with broadband range has attracted lots of research interest for the photo induced reversible-deactivation radical polymerization (RDRP). However, it is still a challenge for a single catalyst to simultaneously respond to various lights with highly varied wavelengths. Here, we proposed a simple strategy for the preparation of a heterogeneous photocatalyst suitable for photo induced atom transfer radical polymerization (photoATRP) under full spectrum (from UV/vis light to NIR), by combining pyridine nitrogen doped carbon dots (N-CDs) and upconversion nanoparticles (UCNPs). In the presence of these robust UCNP@SiO2@N-CDs composite particles, the photoATRP could be carried on under the different irradiations of UV, blue, green, red, white, and 980 nm NIR light, with a low loading of part per million concentrations of the CuBr2/L catalyst. Moreover, the excellent solvent and aqueous compatibility allow UCNP@SiO2@N-CDs to be capable for photoATRP in both organic solvents and aqueous media, providing well-defined hydrophobic and hydrophilic polymers with low dispersity and excellent chain-end fidelity. In addition, the photoATRP with 980 nm NIR exhibited excellent penetrations through visible-light-proof barriers. The system could be used for the preparation of an injectable hydrogel that had dual curing and photoluminescence modes. Owing to the “living” characteristics of polymer chains achieved through ATRP, the hydrogel was capable to be easily repaired by using monomer as the binder.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FOOD CHEMISTRY
·
2022
·
IF 9.231
Kaige Zhang,Rong Guo,Yunhe Wang,Qiujun Nie,Guifen Zhu
In our work, hydrophobic thymol-based deep eutectic solvents (DESs) with strong reducibility, a lower density than water, and a slightly higher melting point than room temperature were synthesized. Based on these solid DESs, one-step derivatization and temperature-controlled vortex-assisted liquid-liquid microextraction based on the solidification of a floating DES (TC-VA-LLME-SFDES) via UV–Vis spectrophotometry for the rapid determination of total iron was developed. The derivatization and TC-VA-LLME were carried out simultaneously by the addition of DES as both the reducing agent and extraction solvent. After optimization, the calibration curve (5–250 μg L −1 , R 2 = 0.9982), limit of detection (1.5 μg L −1 ), limit of quantitation (5.0 μg L −1 ), precision (≤4.0%) and enrichment factor (92) was obtained. This method was applied for the determination of total iron in water and food samples with satisfactory recoveries (85.4–106.2%). One-step derivatization and TC-VA-LLME only required 2 min. Furthermore, this method opened up the application of solid DESs in liquid–liquid microextraction.
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）