FUEL
·
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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DOI
高影响因子
CERAMICS INTERNATIONAL
·
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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DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
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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高影响因子
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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DOI
高影响因子
ACS Sensors
·
2024
·
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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DOI
PubMed
高影响因子
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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高影响因子
MICROCHEMICAL JOURNAL
·
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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高影响因子
ACS Applied Nano Materials
·
2025
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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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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Yuerui Ma,Peng Chen,Jiazhen Liao,Xing’an Dong,Wenjie He,Wendong Zhang
Selective photocatalytic oxidation of NO to nitrate (NO 3 – ) over toxic NO 2 remains challenging due to low selectivity and inefficient charge migration in existing systems. This study introduces Fe 3+ as an electron acceptor beneath a Bi 4 TaO 8 Cl/Bi 2 O 2 CO 3 heterojunction to precisely regulate electron pathways and promote targeted hydroxyl radical ( • OH) generation. Combined experimental and DFT analyses reveal Fe 3+ ’s dual role: enhancing interfacial electron transfer and activating H 2 O at surface sites to form • OH. The optimized heterojunction achieves 68.19 % NO conversion with minimal NO 2 selectivity (10.98 %). ESR and ROS quenching confirm Fe 3+ -driven electron migration enriches surface holes, boosting H 2 O adsorption and • OH production (2.76-fold increase). The strong oxidation capacity of • OH suppresses NO 2 formation, favoring complete NO oxidation to NO 3 – . This work provides a strategic approach for selective NO removal by electron-pathway engineering, advancing the design of eco-friendly photocatalysts for air pollution control.
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SENSORS AND ACTUATORS B-CHEMICAL
·
2025
·
IF 7.7
Huizhang Zhao,Jianhui Lv,Xiao Ma,Bin Huang,Lei Han,Xingyu Kang,Dong Wang,Hairui Fang
NO 2 concentration in soil surface is one of the important indicators affecting soil nitrogen cycle. Real-time detection of NO 2 is crucial to optimize the use of nitrogen fertilizer and improve efficiency, which is also a key means to prevent soil acidification and increase crop yield. However, the humidity conditions on the soil surface increase the challenge of real-time detection of NO 2 . Therefore, a composite material of tungsten oxide (WO 3 ) composite tin sulfide (SnS 2 ) with heterogeneous structure was synthesized by one-step hydrothermal method. The composite material is seen to exist in the form of nanosheets. At the optimal working temperature of 210℃, the response of the composite material (WO 3 /SnS 2 (3:10)) with a molar ratio of WO 3 to SnS 2 of 3:10–20 ppm NO 2 is 63.8. The excellent gas sensing performance is attributed to the composition of heterojunction and the increase of deficiency oxygen. In the relative humidity (RH) range of 20–98 %, the response of the WO 3 /SnS 2 (3:10) has a good linearity ( R 2 =0.995). Therefore, the humidity compensation is integrated into the convenient NO 2 detection equipment to ensure that the WO 3 /SnS 2 (3:10) sensor can detect NO 2 stably and accurately under different humidity conditions. The NO 2 real-time detection system uses the OLED to display the humidity value and NO 2 concentration value in real time on the soil surface, and the buzzer as an alarm device for exceeding the concentration threshold (2 ppm NO 2 ), which reminds staff of the need to take action to adjust crop management strategies to improve crop health.
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高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Hongtao Wang,Yuanchao Xie,Yang Liu,Yaodan Zhang,Jianan Ma,Jiaqi Yang
The enhanced sensitivity and selectivity of NO 2 gas sensors are crucial for atmospheric environmental monitoring. In this study, a novel NO 2 gas sensor based on small-sized ZIF-8/In 2 O 3 core-shell nanocube has been developed through a simple solvothermal method along with in situ modification. The ZIF-8 coating significantly increased the specific surface area of the In 2 O 3 nanocubes from 60.64 m 2 /g to 140.84 m 2 /g, while also boosting the adsorption of oxygen ions on the surface. Gas-sensing tests revealed that the ZIF-8/In 2 O 3 composites exhibited a response of 56.3 to 1 ppm of NO 2 , with an exceptionally low detection limit of 1 ppb. Notably, the sensor demonstrated outstanding selectivity for NO 2 over other potential interfering gases. The remarkable NO 2 sensing performance of the ZIF-8/In 2 O 3 composites can be attributed to the grain boundary effects in the In 2 O 3 nanocubes (with side lengths of approximately 40–50 nm), as well as the sensitizing and filtering effects of the ZIF-8 layer. This work holds significant promise for the rapid detection of low-concentration NO 2 gases in various applications.
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高影响因子
ACS Sensors
·
2023
·
IF 8.9
Huajing Wang,Zhou Cui,Rui Xiong,Xiaoxia Wang,Wulin Song,Xiang Guo,Xiao Wu,Baisheng Sa,Dawen Zeng
Although two-dimensional (2D) transition-metal dichalcogenides (TMDs) exhibit attractive prospects for gas-sensing applications, the rapid and precise sensing of TMDs at low loss remains challenging. Herein, a NO2 sensor based on an expanded VS2 (VS2-E)/carbon nanofibers (CNFs) composite (abbreviated as VS2-E-C) with ultrafast response/recovery at a low-loss state is reported. In particular, the impact of the CNF content on the NO2-sensing performance of VS2-E-C was thoroughly explored. Expanded VS2 nanosheets were grafted onto the surface of hollow CNFs, and the combination boosted the charge transport, exposing abundant active edges of VS2, which enhanced the adsorption of NO2 efficiently. The activity of the VS2 edge is further confirmed by stronger NO2 adsorption with a more negative adsorption energy (−3.42 eV) and greater than the basal VS2 surface (−1.26 eV). Moreover, the exposure of rich edges induced the emergence of the expanded interlayers, which promoted the adsorption/desorption of NO2 and the interaction of gas molecules within VS2-E-C. The synergism of edge effect and interlayer engineering confers the VS2-E-C3 sensor with ultrafast response/recovery speed (9/10 s) at 60 °C, high sensitivity (∼2.50 to 15 ppm NO2), good selectivity/stability, and a low detection limit of 23 ppb. The excellent “4S” functions indicate the promising prospect of the VS2-E-C3 sensor for fast and precise NO2 detection at low-loss condition.
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DOI
PubMed
高影响因子
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