CHEMICAL ENGINEERING JOURNAL
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2022
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IF 16.744
Li Xia,Wenxi Zhou,Yifan Xu,Zhengqiang Xia,Xinzhi Wang,Qi Yang,Gang Xie,Sanping Chen,Shengli Gao
The introduction of rich-electron ligands is a promising strategy to improve the ligand-to-metal charge transfer (LMCT) ability of metal–organic frameworks (MOFs) for efficient photocatalytic CO 2 reduction reactions (CO 2 RR), while the resulting impaired Lewis acid sites go against stable bonding with CO 2 and hinder the electron transfering to CO 2 . It is thus the key to search a trade-off between increasing LMCT and frustrating Lewis acid. Herein, the ferrocene (Fc) modified UiO-66 series MOFs, NH 2 -UiO-66-Fc, have been prepared to optimize LMCT for boosting CO 2 RR through a simple solvent-assisted ligand incorporation (SALI) method. Theoretical calculation and systematic experiments, including photoelectrochemical measures, in situ electron paramagnetic resonance, fluorescence probe analysis and X-ray photoelectron spectroscopy indicate that with increasing Fc content, the LMCT energy of MOFs significantly decreases from 2.66 to 2.10 eV based on the established electron transfer double-channel mechanism, while the Lewis acidity of Zr sites reduces with the CO 2 adsorption energy ( E ad ) ranging from −1.061 to −0.632 eV. Through introducing an optimal Fc content, NH 2 -UiO-66-Fc (2.0) integrating satisfactory LMCT ability and Lewis acidity shows superior photocatalytic CO 2 RR performance (CO yield: 90.65 μmol·g −1 ·h −1 ), about 13 times higher than that of the unmodified MOF and superior to most reported pristine MOF photocatalysts. DFT calculation demonstrates that the excellent performance of NH 2 -UiO-66-Fc (2.0) is attributed to the lowest energy barrier of 1.50 eV for the rate-limiting step of *COOH formation. In this work, such a simple post-modification strategy for facilitating the whole electron transfer path of photocatalytic CO 2 RR will provide a new way to construct high-performance MOFs-based CO 2 RR photocatalysts.
研究领域:
材料科学
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环境科学
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化学
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DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
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2022
·Vol. 24
·期 22
·13661-13670
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IF 3.945
Si-Yuan Yu,Ying Liu,Hai-Tao Ren,Zhao-Yu Liu,Xu Han
Photooxidation of As(III) by TiO2 is a complicated process in which the oxidation mechanisms are always controversial. In this study, the enhanced photooxidation rates of As(III) with increasing pH values from 8.0 to 11.0 indicate the high photocatalytic reactivity of TiO2 under alkaline conditions. Moreover, As(III) improves the production of H2O2, indicating H-abstraction from As(III) (soluble or adsorbed) for H2O2 production. Although O2˙−, h+, ˙OH and –OOH are always regarded as the reactive oxygen species in the UV-TiO2 system, the superoxo and peroxo species formed on the surface of TiO2 also contribute to As(III) oxidation. The As(III)–O–Ti(IV) surface complexes formed on TiO2, as well as the decreased bandgaps of TiO2 with increasing concentrations of As(III) indicate that the ligand-to-metal charge transfer (LMCT) pathway also contributes to the oxidation of As(III) under alkaline conditions. Electrochemical analyses further reveal that As(III) enhances the electron density on the surface of TiO2, thereby improving the catalytic reactivity of TiO2. We therefore suggest that H-abstraction from As(III) or H2O to the formed superoxo and peroxo species results in the formation of H2O2, accompanied by the oxidation of As(III). This enriches our knowledge on the oxidation of As(III), as well as other contaminants rich in –OH groups during the photocatalytic oxidation processes.
研究领域:
环境科学
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化学
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DOI
PubMed
高影响因子
CHINESE JOURNAL OF CHEMISTRY
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2020
·Vol. 38
·期 11
·1332-1338
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IF 3.826
Meichen Li,Yaru Li,Jingyu Zhao,Mingcheng Li,Yongchuan Wu,Ping Na
Summary of main observation and conclusion The AL-P25 composites (AL = alizarin, P25 = nano titanium dioxide) with oxygen vacancies were synthesized by a simple hydrothermal method and applied for the photoreduction of Cr(VI) under visible light. The AL-P25 composites were characterized by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy analysis, Fourier transform infrared spectrometer, thermo-gravimetric analysis, UV–vis diffuse reflectance spectroscopy, photoluminescence spectroscopy and electron paramagnetic resonance spectroscopy. The results suggested that the AL-P25 composites were successfully prepared, and alizarin was linked to P25 via Ti—O—C bonds. AL-P25 composites represented excellent photoreduction efficiency on Cr(VI) under visible light, which was 99.4% after 60 min of illumination. Finally, a photocatalytic mechanism of AL-P25 composites was proposed that ligand-metal charge transfer (LMCT) process between alizarin and P25 effectively enhances separation efficiency of photogenerated electrons and holes.
研究领域:
材料科学
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环境化学
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光化学
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DOI
高影响因子
RSC Advances
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2014
·Vol. 4
·期 32
·16612-16617
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IF 3.708
Keli Zhong,Xue Zhou,Ruibin Hou,Pei Zhou,Shuhua Hou,Yanjiang Bian,Gang Zhang,Lijun Tang,Xiaohong Shang
A water-soluble fluorescent sensor (L) based on 2-(2-(8-hydroxyquinolin)-yl)benzimidazole has been synthesized and characterized. Sensor L displays highly selective and sensitive recognition of Hg2+ with a fluorescence “ON–OFF” response in buffered aqueous solution (1% dimethyl sulfoxide (DMSO), Tris–HCl 10 mM, pH = 7.4). X-ray crystal structure of the L–Hg2+ complex reveals that the oxygen and nitrogen atoms of 8-hydroxyquinoline and the imine N atom of the benzimidazole unit (N1) bind Hg2+ through a 1 : 1 binding stoichiometry. The fluorescence quenching mechanism is qualitatively evaluated by quantum chemical calculations which show that the fluorescence quenching phenomenon is caused by ligand-to-metal charge transfer (LMCT) in the excited state.
研究领域:
分析化学
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环境科学
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DOI
高影响因子
MOLECULES
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2022
·Vol. 27
·期 15
·4673
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IF 4.927
Yanru Liu,Jingyun Mao,Yiwei Huang,Qingrong Qian,Yongjin Luo,Hun Xue,Songwei Yang
The Pt-chitosan-TiO2charge transfer (CT) complex was synthesized via the sol-gel and impregnation method. The synthesized photocatalysts were thoroughly characterized, and their photocatalytic activity were evaluated toward H2production through water reduction under visible-light irradiation. The effect of the preparation conditions of the photocatalysts (the degree of deacetylation of chitosan, addition amount of chitosan, and calcination temperature) on the photocatalytic activity was discussed. The optimal Pt-10%DD75-T200 showed a H2generation rate of 280.4 μmol within 3 h. The remarkable visible-light photocatalytic activity of Pt-chitosan-TiO2was due to the CT complex formation between chitosan and TiO2, which extended the visible-light absorption and induced the ligand-to-metal charge transfer (LMCT). The photocatalytic mechanism of Pt-chitosan-TiO2was also investigated. This paper outlines a new and facile pathway for designing novel visible-light-driven photocatalysts that are based on TiO2modified by polysaccharide biomass wastes that are widely found in nature.Keywords:photocatalyst;TiO2;chitosan;H2evolution;LMCT;visible light
研究领域:
材料科学
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环境科学
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产品关联
DOI
PubMed
高影响因子
ANALYTICA CHIMICA ACTA
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2026
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IF 6.1
Haiyan Cao,Bin Yang,Wenfei Dong,Wenbing Shi
Background The accurate detection of 2,3,5,6-tetramethylpyrazine (TMP) in complex matrices is significant for food quality control and biomedical analysis. Despite this need, a dedicated optical sensing platform for TMP has not been reported to date. Results Here, we present a novel ratiometric fluorescent probe based on a Tb–EDTA complex, which introduces a sensing strategy founded on coordination-induced modulation of the ligand-to-metal charge transfer (LMCT) process. Specific coordination of TMP's pyrazine nitrogen atoms to the Tb 3+ center results in a characteristic ratiometric response: quenching of the emission at 548 nm and concomitant enhancement at 650 nm. The probe exhibits excellent analytical performance with a linear range of 0.1―40 μM, a detection limit of 0.038 μM, and high selectivity over structurally similar interferents. Its practical applicability is demonstrated by reliable quantification of TMP in real samples, including sauce-flavor Baijiu, sake, and human urine, with recoveries of 94.54–104.82% and relative standard deviations below 10.57%. Significance This work establishes a pioneering optical sensing approach for TMP detection, providing a valuable analytical tool for flavor assessment in alcoholic beverages and pharmacological monitoring in biological systems.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
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2026
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IF 12.5
Xin Li,Tong Wu,Zhiqiang Jia,Tong Hao,Hong Zheng
A widely applicable Zn-DMTD-MOGs was prepared via direct construction strategy. • Zn-DMTD-MOGs shows great potential for trace heavy metals removal from real water. • DFT provides a local coordination cluster model for amorphous MOGs at atomic scale. • Synergistic chelating/monodentate coordination and LMCT enable efficient lead capture. Metal-organic gels (MOGs) have attracted extensive attention in the field of heavy metal removal, owing to their advantages including ease of surface modification, good stability, hierarchical pore structure, tunable functional groups, and mild and facile preparation conditions. However, the existing MOGs still leave considerable room for performance improvement. To produce MOGs with enhanced adsorption sites, high specific surface area, and greater pore volume, this study combined ultrasound-assisted nucleation with a high-concentration reaction strategy and triethylamine-mediated deprotonation, thereby enabling direct coordination between 2,5-Dimercapto-1,3,4-thiadiazole (DMTD) and Zn 2+ . Then, Zn-DMTD-MOGs material with higher-density N and S adsorption sites was successfully synthesized. The material exhibits a disordered particle-stacked amorphous structure with abundant mesopores (3–24 nm). Adsorption experiments demonstrate that the material achieves a trace Pb(II) removal efficiency of 96.98% within 10 s. The material achieves wide applicability over a low concentration range (≤ 42 mg/L) and a broad pH range (3.5–10.5), along with favorable stability, good reusability, and applicability to real water matrices. A local coordination cluster model was obtained through density functional theory (DFT) geometry optimization, and a synergistic chelating/monodentate coordination and ligand-to-metal charge transfer (LMCT) mechanism was established. The analysis reveals that the material adsorbs Pb(II) primarily through chelation at dual N/S sites and monodentate coordination at single S sites. This mechanism endows Zn-DMTD-MOGs with ultrafast adsorption kinetics and excellent cyclic stability, making them promising candidates for heavy metal remediation in drinking water sources. Download: Download high-res image (120KB) Download: Download full-size image
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高影响因子
RSC Advances
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2021
·Vol. 11
·期 28
·17283-17290
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IF 3.361
Shuai Zhang,Cong Zhang,Xiaodong Shao,Rentian Guan,Yingying Hu,Keying Zhang,Wenjing Liu,Min Hong,Qiaoli Yue
A fluorometric method was proposed for the determination of Fe3+ and ascorbic acid (AA) based on blue and red dual fluorescence emissions of glutathione (GSH) stabilized-gold nanoclusters (AuNCs). AuNCs were synthesized from GSH and tetrachloroauric acid. The fluorescence peaks of AuNCs were at 425 nm and 585 nm, respectively. In the presence of Fe3+, the fluorescence peak at 425 nm can be enhanced and that at 585 nm can be quenched. There is a good linear relationship between the fluorescence intensity ratio for the 425 and 585 nm peaks (F425/F585) and the concentration of Fe3+ in the range of 0.75–125 μM. However, when AA was added to the AuNCs–Fe3+ system, the value of F425/F585 decreased consistently with the concentration of AA in the range of 0.25–35 μM. The limit of detection for Fe3+ and AA was 227 and 75.8 nM, respectively. The interaction between AuNCs and Fe3+ can induce the ligand–metal charge transfer (LMCT) effect leading to the fluorescence increment at 425 nm, while AA can reduce Fe3+ to Fe2+. The production of Fe2+ can not enhance or quench the fluorescence of AuNCs. By comparison with previous literature, the AuNCs prepared here show two fluorescence peaks without additional fluorescence labels. Furthermore, the method was successfully applied in the determination of Fe3+ and AA in some real samples, such as water, human serum and tablets.
研究领域:
分析化学
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纳米技术
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环境科学
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生物化学
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DOI
PubMed
高影响因子
Catalysis Science & Technology
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2021
·Vol. 11
·期 21
·7060-7071
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IF 6.119
Kaiyue Zhang,Guilong Lu,Feng Chu,Xiubing Huang
Thermo-enhanced photocatalysis has been reported as a potential strategy for improving the activity, whereas the relationship between thermal energy and the localized surface plasmon resonance (LSPR) effect of noble metal nanoparticles has been rarely investigated. Herein, photocatalytic selective aerobic oxidation of amines to imines is investigated under visible light irradiation over heterostructured TiO2(B)/anatase and Au/TiO2 nanobelts at specific temperatures (20–60 °C). The surface amine substrate complexed on TiO2 could broaden the visible-light absorption region via the ligand-to-metal charge transfer (LMCT) effect. Interestingly, the pristine TiO2 achieves the best photocatalytic performance (>99% benzylamine conversion and >99% N-benzylidenebenzylamine selectivity) at 60 °C after 12 h irradiation while the Au nanoparticles (NPs) are observed to improve the activity of TiO2 only in a low temperature range (<40 °C). Moreover, excessive Au NPs loaded on TiO2 could inhibit the amine conversion and reduce the imine selectivity in the whole temperature range of 20–60 °C, which is attributed to the decreased oxygen vacancies and poor amine adsorption ability on the surface of Au/TiO2. A plausible explanation is finally proposed that the substrate–TiO2 complex, instead of plasmonic Au NPs, plays a vital role in achieving good amine conversion and imine selectivity.
研究领域:
光催化
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材料科学
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化学工程
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物理化学
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DOI
高影响因子
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