MOLECULES
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2021
·Vol. 26
·期 19
·5736
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IF 4.412
Chunhua Wang,Zhiquan Yu,Yuhao Yang,Zhichao Sun,Yao Wang,Chuan Shi,Ying-Ya Liu,Anjie Wang,Karen Leus,Pascal Van Der Voort
Upgrading furfural (FAL) to cyclopentanone (CPO) is of great importance for the synthesis of high-value chemicals and biomass utilization. The hydrogenative ring-rearrangement of FAL is catalyzed by metal-acid bifunctional catalysts. The Lewis acidity is a key factor in promoting the rearrangement of furan rings and achieving a high selectivity to CPO. In this work, highly dispersed Pd nanoparticles were successfully encapsulated into the cavities of a Zr based MOF, UiO-66-NO2, by impregnation using a double-solvent method (DSM) followed by H2reduction. The obtained Pd/UiO-66-NO2catalyst showed a significantly better catalytic performance in the aforementioned reaction than the Pd/UiO-66 catalyst due to the higher Lewis acidity of the support. Moreover, by using a thermal treatment. The Lewis acidity can be further increased through the creating of missing-linker defects. The resulting defective Pd/UiO-66-NO2exhibited the highest CPO selectivity and FAL conversion of 96.6% and 98.9%, respectively. In addition, the catalyst was able to maintain a high activity and stability after four consecutive runs. The current study not only provides an efficient catalytic reaction system for the hydrogenative ring-rearrangement of furfural to cyclopentanone but also emphasizes the importance of defect sites.Keywords:Pd/UiO-66-NO2;furfural;hydrogenative ring-rearrangement;cyclopentanone;double-solvent method
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高影响因子
FUEL
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2019
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IF 5.128
Xiao Zhu,Liqiang Zhang,Mengze Zhang,Chunyuan Ma
Due to high adsorption capacity, NO 2 adsorption using activated carbon has become a potential denitration technology. A correlation between N-doping and NO 2 adsorption process on activated carbon is pointed out by previous studies but lacks a clear explanation. The main objective of this work is to clarify the influencing mechanism of N-doping on NO 2 adsorption and reduction over activated carbon. N-doped activated carbons were synthesized by melamine impregnation followed by calcination and tested as NO 2 adsorbents. Experimental results showed that AC600 with highest N content possessed highest NO 2 adsorption capacity and lowest NO release percentage. NO 2 adsorption on activated carbon is a complex process, including NO 2 adsorption, NO 2 reduction to NO, and NO release. Density functional theory calculations results showed that N-doping affected all steps mentioned above. Firstly, N-doping increased NO 2 physisorption energies, meaning that NO 2 was easier to be adsorbed. Thus, NO 2 adsorption capacities increased with the increase of N content experimentally. Secondly, N-doping increased the energy barrier of the rate-determining step of NO 2 reduction. Thus, the reduction of NO 2 to NO was harder. Thirdly, N-doping increased NO desorption energies, implying that the release of generated NO was harder. The inhibition of NO 2 reduction and NO desorption results in the decrease of NO release percentage due to N-doping jointly. This work elucidates the influencing mechanism of N-doping on NO 2 adsorption and NO 2 reduction on theoretical level, which fills up the research gap and guides the design of activated carbon for efficient NO 2 adsorption.
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CERAMICS INTERNATIONAL
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2019
·
IF 3.45
Yunshi Liu,Xiupeng Liu,Yubing Wang,Rui Wang,Tong Zhang
A novel synthesis of In 2 O 3 porous microcolumnar structures (MCs) by a self-sacrificial template route was carried out using MIL-68. Using a modified calcination strategy, the samples could maintain the original metal organic frame work (MOF) morphology with a high gas accessibility after a slow decomposition of organic ligands. Pt nanoparticles (NPs) were loaded on the samples before or after the MOF calcination, leading to different contact states of the Pt NPs and In 2 O 3 matrix. The gas sensing properties of the samples were systematically investigated using a dynamic testing system. Particularly, sample Pt/In 2 O 3 MCs-1 exhibited a superior NO 2 sensing performance near room temperature ( R g / R a = 44.9 at 1 part-per-million and 5.2 at 100 parts-per-billion (ppb)). The sensor resistance could recover to its baseline even at 40 °C after purging with air without any additional treatment. This can be attributed to the chemical sensitisation of the Pt NPs as well as large contents of pores and channels for gas diffusion. The introduction of humidity in the gas mixture could remarkably decrease the sensor response and recovery times owing to the ‘wet’ NO 2 adsorption mechanism. This study demonstrated a novel synthesis route of Pt-loaded In 2 O 3 porous columnar structures and its potential applications in near-room-temperature detection of ppb-level NO 2 .
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JOURNAL OF ALLOYS AND COMPOUNDS
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2019
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IF 4.175
Tianyi Han,Shang Gao,Ziying Wang,Teng Fei,Sen Liu,Tong Zhang
A series of reduced graphene oxide (rGO) samples were prepared by hydrothermal reduction of graphene oxide (GO) samples, which were obtained by a modified Hummers’ method at oxidation temperatures of 65 °C, 75 °C, 85 °C, and 95 °C. The combined characterizations indicate that the number of C–O bonds in rGO samples increases with an increasing oxidation temperature of GO from 65 °C to 85 °C and then decreases when the temperature is further increased to 95 °C. Most importantly, the rGO obtained from the GO at an oxidation temperature of 85 °C (designated as rGO-85) exhibits a higher response to 5 ppm NO 2 (36.7%) at room temperature than the other three rGO samples, which is attributed to the high content of C–O bonds in the rGO-85 sample. This work suggests that the gas sensing properties of rGO-based sensors can be tuned by changing the number of oxygen-containing groups in rGO.
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APPLIED SURFACE SCIENCE
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2019
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IF 5.155
Yujiao Zhang,Xiaoli Cheng,Xianfa Zhang,Zoltán Major,Yingming Xu,Shan Gao,Hui Zhao,Lihua Huo
Tungsten trioxide (WO 3 ) nanoparticles were synthesized via a fancil hydrothermal method with the addition of small amount of ionic liquid 1-butyl-3-methyl tetrafluoroborate ([Bmim]BF 4 ). The as-synthesized WO 3 nanoparticles were calcined at various temperatures to yield final products, which were characterized by X-ray powder diffraction meter (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), Fourier transform infrared spectra (FT-IR) and N 2 adsorption-desorption methods. The sensor based on WO 3 nanoparticles that have been calcined at 500 °C for 2 h exhibits an excellent selective response to sub-ppm level NO 2 at temperatures less than 50 °C. Its resistance to humidity and stability are also good at the same condition. Besides, the detection limit for the gas sensor towards NO 2 is 100 ppb. The mechanism of NO 2 sensing was characterized and the reasons for improved NO 2 sensing performance in WO 3 nanoparticles were also proposed.
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CHINESE JOURNAL OF CATALYSIS
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2018
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IF 3.525
Lei Chen,Ding Weng,Jiadao Wang,Duan Weng,Li Cao
The CeO 2 -TiO 2 (CeTi) and CeO 2 /WO 3 -TiO 2 (CeWTi) catalysts were prepared by a sol-gel precipitation method and their NH 3 -NO/NO 2 selective catalytic reduction (SCR) performance was studied. N 2 O formation and effect of oxygen concentration on SCR performance over CeWTi catalyst were also investigated while varying the NO 2 /NO x ratio. Results indicate that fast SCR behavior of CeWTi catalyst has the best NH 3 -NO/NO 2 SCR performance due to the catalyst reoxidation rate by NO 2 higher than by O 2 . Compared with CeTi catalyst, CeWTi catalyst exhibits higher de-NO x performance under NH 3 -NO/NO 2 SCR conditions. As the CeTi and CeWTi catalysts exhibit similar redox property, addition of WO 3 provides more acid sites which accelerate the reaction between NH 4 NO 3 and NO to get a superior low-temperature activity. Amount of N 2 O formation shows a peak at 250 °C mainly derived from NH 4 NO 3 decomposition.
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ACS Sensors
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2024
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IF 8.2
Chao Fan,Jianhua Yang,Jaafar Abdul-Aziz Mehrez,Yongwei Zhang,Wenjing Quan,Jian Wu,Xue Liu,Min Zeng,Nantao Hu,Tao Wang,Bing Tian,Xiaopeng Fan,Zhi Yang
Rapid and ultrasensitive detection of toxic gases at room temperature is highly desired in health protection but presents grand challenges in the sensing materials reported so far. Here, we present a gas sensor based on novel zero dimensional (0D)/two dimensional (2D) indium oxide (In2O3)/titanium carbide (Ti3C2Tx) Schottky heterostructures with a high surface area and rich oxygen vacancies for parts per billion (ppb) level nitrogen dioxide (NO2) detection at room temperature. The In2O3/Ti3C2Tx gas sensor exhibits a fast response time (4 s), good response (193.45% to 250 ppb NO2), high selectivity, and excellent cycling stability. The rich surface oxygen vacancies play the role of active sites for the adsorption of NO2 molecules, and the Schottky junctions effectively adjust the charge-transfer behavior through the conduction tunnel in the sensing material. Furthermore, In2O3 nanoparticles almost fully cover the Ti3C2Tx nanosheets which can avoid the oxidation of Ti3C2Tx, thus contributing to the good cycling stability of the sensing materials. This work sheds light on the sensing mechanism of heterojunction nanostructures and provides an efficient pathway to construct high-performance gas sensors through the rational design of active sites.
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SENSORS AND ACTUATORS B-CHEMICAL
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2024
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IF 8
Shihang Yan,Zhengrun Chen,Ya Wang,Jieqiang Wang,Hongyan Xu
For NO 2 , a gas that is widely used and harmful, domestic and foreign researchers have done a lot of work to develop a sensor with low detection limit and low humidity sensitivity to achieve efficient detection of NO 2 . In this work, first of all, dense and uniform SnO 2 nanosheets were grown in situ on the surface of Al 2 O 3 ceramic tube by hydrothermal method. Then, the ZIF-8@SnO 2 porous composite gas-sensitive material was constructed by solvent thermal method. With the advantages of the ZIF-8 porous screening framework, the permeation of different gases can be selectively controlled, and the adsorption efficiency of NO 2 gas can be enhanced through the modification of ammonia to improve the selectivity of NO 2 . The results show that the response of the Modified-ZIF-8@SnO 2 sensor is significantly enhanced, and the selectivity is greatly improved at low operating temperature. At 140 °C, the response of Modified-ZIF-8@SnO 2 to 50 ppm NO 2 gas is as high as 61, which is about 18.4 times higher than that of SnO 2 nanosheets and about 16.3 times higher than that of ZIF-8@SnO 2 . Meanwhile, the anti-interference ability of the Modified-ZIF-8@SnO 2 sensor to humidity has been improved. This work provides a new idea for improving the selectivity and humidity insensitivity of gas sensors.
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MICROCHEMICAL JOURNAL
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2025
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IF 5.1
Gen Li,Jinan Li,Ya Wang,Yuhang Du,Hongyan Xu,Yan Wang
In this research, a two-step hydrothermal method was used to fabricate a NO 2 sensor based on WO 3 @ZIF-8 core-shell nanorods grown on ceramic tubes. The material's morphology, nanostructure, and composition were thoroughly characterized. The nanocomposites consisting of WO 3 @ZIF-8 showed significant sensing response (65) toward 50 ppm NO 2 at 200 °C. The WO 3 @ZIF-8 core-shell nanomaterials demonstrated exceptional selectivity to NO 2 against TEA and possessed good repeatability. Moreover, the distinctive core-shell nanorods structure promote the process of transferring the electrical charge of the carrier and the response to the targeted gas. The outer coating of ZIF-8 microporous material, with small pore window size (0.5–0.7 nm), had a sieving effect on large molecular interference gases. Further, we combined density functional theory (DFT) calculations and molecular dynamics simulations to investigate the reaction mechanism of the sensors.
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ACS Applied Nano Materials
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2025
·
IF 5.5
Zixu Wang,Linna Han,Qing Xia,Wanfang Feng,Songtao Li,Liyan Liu
Enrichment and quantification of sugar phosphates (SPx) in biological samples are of great significance in biological medicine. In this work, a magnetic nanoscale metal–organic framework composite, Fe3O4@UiO-66-NO2, was synthesized and utilized as a high-capacity adsorbent for the enrichment of SPx in biological samples. Fe3O4@UiO-66-NO2 exhibited a high specific surface area (310.02 m2/g), a suitable pore size (3.47 nm), and strong magnetism (14.99 emu/g), enabling convenient separation and recovery. Experimental results demonstrated that Fe3O4@UiO-66-NO2 exhibited excellent adsorption performance for five types of SPx, achieving complete adsorption within 6 min at a dosage of 200 μg, and the adsorption process exhibited pH tolerance. The adsorption isotherm result indicated that the maximum adsorption capacities for different SPx ranged from 234.06 mg/g to 403.24 mg/g. Adsorption mechanisms using X-ray photoelectron spectroscopy, FT-IR, and density functional theory revealed multiple interactions, such as coordination and hydrogen bonding, and contributed to the adsorption process. A magnetic nanoscale-dispersive solid-phase extraction protocol was developed based on a Fe3O4@UiO-66-NO2 for rapidly enriching SPx from biological samples. The protocol allowed for SPx detection over a wide linear concentration range, low limits of detection (0.001–0.02 ng/mL), high precision (<7.88%), and good accuracy (82.56%–119.66%). This protocol was successfully applied to real blood samples, prefiguring the great potential of magnetic MOFs for the enrichment and detection of SPx in biological samples.
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SENSORS AND ACTUATORS B-CHEMICAL
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2025
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IF 7.7
Jiahui Fan,Guiting Wang,Rui Zhang,Xu Guo,Kun Li,Junwei Zhou,Jingfeng Wu,Kai Pan,Keying Shi
High-performance gas-sensitive materials must exhibit improved resistance to moisture essential criterion for their effectiveness. In this work, monodisperse triangle MnO nanocrystals were synthesized through the hot injection method. Then, they were evenly spread across the reduced graphene oxide (rGO) surface in a uniform dispersion. The optimized MnO/rGO exhibited high sensitivity (R a /R g =47.0) and quick response, with a lower detection limit. Furthermore, it shows strong moisture resistance in a high-humidity environment (80 % relative humidity). The comprehensive wrapping of stearate ligands proved highly effective in preventing water vapor infiltration. This robust shielding significantly boosted the composite's hydrophobic nature, markedly enhancing its resistance to moisture. This approach offers a pioneering avenue for gas sensors to detect NO 2 effectively at room temperature, even within high-humidity environments.
研究领域:
材料科学
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纳米科技
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传感器技术
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环境监测
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表面化学
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RARE METALS
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2025
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IF 11
Qiu-Yue Zheng,Xiao-Li Cheng,Jing Tang,Ting-Ting Wang,Xian-Fa Zhang,Li-Hua Huo,Chao-Bo Huang,Zoltán Major,Yong-Sheng Zhang,Peng-Jin Ye,Ying-Ming Xu
en Introducing oxygen vacancies has emerged as an essential strategy to affect the sensing properties of nanomaterials. However, existing methods for manipulating oxygen require high cost, complex operation, and harsh conditions. Herein, a simple NH 4 + -assisted heat treatment approach was designed to regulate the concentration of oxygen vacancies of ammonium tungsten bronze ((NH 4 ) 0.25 WO 3 , named as NWO). The resultant NWO-300 sensor exhibited an extremely high response of 118 to 1 ppm NO 2 at 40°C. It achieved a detection limit as low as 10 ppb. Such outstanding sensing properties of NWO-300 were ascribed to the modulated electronic structure and increased active sites caused by oxygen vacancies. The formation of a large number of oxygen vacancies in NWO-300 is due to the H and N atoms in NH 3 can extract O atoms on the surface of materials, which was confirmed by X-ray photoelectron spectroscopy (XPS) and thermogravimetric-mass spectrometry (TG-MS) techniques. Moreover, the excellent NO 2 detection ability of the NWO-300 sensor enables the detection of air quality under different floors, and its development can be utilized in the field of environmental monitoring applications. 摘要 zh 引入氧空位已成为影响纳米材料传感性能的一项关键策略。然而, 现有调控氧空位的方法成本高昂、操作复杂且条件苛刻。因此, 设计了一种简单的NH 4 + 辅助热处理方法来调节铵钨青铜 ((NH 4 ) 0.25 WO 3 , 命名为NWO) 中氧空位的浓度。制备的NWO-300传感器在40 °C时对1 ppm 的NO 2 显示出高达118的响应, 其检测限低至10 ppb。NWO-300传感器如此出色的传感性能归因于氧空位所导致的电子结构的调节和活性位点的增加。NWO-300中大量氧空位的形成是由于NH 3 中的H和N原子可以从材料表面提取O原子, 这一点通过XPS和TG-MS技术得到了证实。此外, 由于NWO-300传感器出色的NO 2 检测能力使其能够检测不同楼层的空气质量, 其开发可用于环境监测领域。
研究领域:
材料科学
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气体传感
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纳米材料
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环境监测
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