查找使用阿拉丁产品的科研文献

Amperometric type NO2 sensor based on La0.75Sr0.25Cr0.5Fe0.5O3-δ-Bi2O3 sensing electrode prepared by self-demixing

Shuang Qi,Lei Dai,Weiwei Meng,Yuehua Li,Ling Wang

Bi 2 O 3 modified La 0.75 Sr 0.25 Cr 0.5 Fe 0.5 O 3-δ (LSCF) composites have been successfully prepared by self-demixing and used as the sensing electrode (SE) of an amperometric NO 2 sensor with yttria stabilized-zirconia (YSZ) electrolyte. The Bi 2 O 3 modified LSCF composites were formed from precursor La 0.75 Sr 0.25 Bi x Cr 0.5 Fe 0.5 O 3+δ (x = 0, 5%, 10%, 20%, 30% and 40%) after calcining at 1200 °C. The particle size of LSCF was increased with the Bi 2 O 3 content increasing. The YSZ porous framework structures were fabricated on YSZ to prolong TPB and the LSCF-xBi 2 O 3 -SE with porous structure was prepared on the porous YSZ backbone after calcining at 1000 °C. It is found that the sensors attached with LSCF-xBi 2 O 3 -SE are more sensitive to different concentrations of NO 2 (25–300 ppm) than the LSCF-based sensor. Among them, LSCF-20% Bi 2 O 3 based sensor exhibits the highest sensitivity (0.301 μA /ppm at 550 °C). The relationship between Δ I s and NO 2 concentrations of the sensor varies linearly at a given temperature. Meanwhile, the sensor shows well anti-interference capability for co-existent gases.

Intensification of NO2 removal in sulfite solutions with reusable copper chloride: Mechanism and process parameters

SuSu Liu,Zheng Lian,Mingjia Zhang,Shule Zhang,Qin Zhong

A novel strategy was proposed to scrub NO x pollutant originated from sintering flue gases by oxidation combined with wet flue gas denitrification technology. CuCl 2 that could be adopted repeatedly was introduced as an additive into the sulfite solution to enhance NO 2 removal. Comparing with the sulfite solution (0.05 mol/L), the absorption efficiency improved from 75% to 100%, and the stabilization period extended from 10 to 40 min notably with the addition of CuCl 2 . The intensification by CuCl 2 addition was related to the formation of CuCl during the reaction of CuCl 2 and SO 3 2− , which was found to be more effective in removing NO 2 . Afterwards, CuCl transformed to Cu 2+ substance again and this mutual transformation between CuCl and Cu 2+ substance indicated a cyclic use of CuCl 2 additive. Moreover, the feasible reaction pathway was further proved by DFT calculations. Additionally, the investigation on NO 2 absorption at various operating parameters provided theoretical support for the practical application of CuCl 2 in denitrification.

Enhancing the performance of mixed-potential NO2 sensors by optimizing the micromorphology of La0.8Sr0.2MnO3 electrodes

Xianwei Qian,Jie Zou,Xiaoqing Jiang,Xuebin Li,Liang Shan,Guangzhong Xie,Jiawen Jian

La 0.8 Sr 0.2 MnO 3 (LSMn) was prepared as a sensing electrode (SE) for mixed-potential type NO 2 sensors, and the effects of porous micromorphology on sensing performance were studied. The results showed that the grain size of La 0.8 Sr 0.2 MnO 3 and the pore size of the SEs were regulated by sintering time . The sensitivity of the sensors increased and then decreased as the pore size increased. Selectivity was optimized via the sintering time. Finally, a NO 2 sensor with SEs sintered at 1100 °C for 2 h showed commercially viable performance at 550 °C. These results indicate that the regulation of porous LSMn SE by sintering time could be applied in mixed-potential type NO 2 sensors and is therefore a candidate for the monitoring of high-temperature exhaust.

Fabrication of Sx/In2O3−x based microsphere for photoexcitation enhancing the NO2 gas detection properties

Yue Song,Bing Yang,Ziyu Ma,Yang Song,Jianbo Sun

Development research as a NO 2 gas sensor has attracted extensive attention recently. However, how to improve the electrical conductivity of materials, adjust the band structure of materials through photoexcitation and improve the carrier lifetime is still a challenge. In this work, an S-doped In 2 O 3 structure (S x /In 2 O 3−x ) was synthesized by enforcing the simple hydrothermal method . Doping directly controls the distribution of structural defects and oxygen vacancies in the material structure, and the response to NO 2 increases by orders of magnitude under photoexcitation. Various structural characterization techniques examined the properties of the S x /In 2 O 3−x -based material. More specifically, its electro-optical properties and the impact of S doping on its energy band structure were thoroughly analyzed to investigate the origins of the enhanced responsivity .

2D/0D SnSe2/TiO2 nanocomposites for trace NO2 detection under H2S interference at room temperature

Chengjiu Zhao,Xuezheng Guo,Yanqiao Ding,Chengyao Liang,Bingsheng Du,Wen Niu,Weijie Qu,Yijie Shi,Shuren Cong,Gang Meng,Yong He

Complex gas environments and the demand for room temperature detection will provide challenges for chemo-resistive-type gas sensors in a variety of applications. In this work, 2D/0D SnSe 2 /TiO 2 composite is used as a sensing material, displaying good sensitivity and specificity to ppb-level NO 2 at ambient temperature (25 °C). The response value and time of the SnSe 2 /TiO 2 sensor are 207 % and 139s when exposed to 100 ppb NO 2 , as opposed to 62 % and 183s for the pristine SnSe 2 sensor. The composite sensor also offers great long-term stability for NO 2 and good gas selectivity. Notably, the SnSe 2 /TiO 2 sensor's mixed gases (NO 2 +H 2 S) measurement is done to examine its NO 2 detection capacity in the presence of interfering gas. The constructed composite sensor can accurately detect NO 2 even if the concentration of the reductive interfering H 2 S is 66.7 times higher than that of the oxidative target NO 2 . The effective usage of SnSe 2 modified by TiO 2 for low-concentration, room-temperature NO 2 detection in a complex gas environment is shown by the composite sensor's pleasing gas detection results.

Enhanced Sensing Performance of Au-decorated Cellulose Nanofiber-SnO2 for NO2 Detection Under UV Light

Zhou Xuebin,Ying Zhihua,He Xingxin,Zhang Chenhan,Zheng Xiaolong,Zheng Peng

Cellulose nanofiber (CNF), a natural polymer material with a high specific surface area, is a potential candidate for gas sensors. Here, we report Au/SnO 2 composites with excellent performance synthesized by a chemical precipitation method based on CNF-assisted synthesis, and a series of Au/SnO 2 composites were prepared by adjusting the Au content. The sensitivity of the 1.5 wt.% Au/SnO 2 sensor to a low concentration of 1 ppm NO 2 was 53, nearly 17 times higher than that of pure SnO 2 synthesized by CNF, under ultraviolet (UV) irradiation at a wavelength of 365 nm. The crystal structure of the composite was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), revealing that the composites had high crystallinity and particles reaching the nanoscale. Further experimental data showed that the CNF-assisted synthesis Au/SnO 2 sensors had good selectivity, repeatability, and stability. Additionally, the sensor is able to maintain its excellent gas sensing performance even under varying humidity conditions.

Au- or Ag-Decorated ZnO-Rod/rGO Nanocomposite with Enhanced Room-Temperature NO2-Sensing Performance

Ke Huang,Junfeng Lu,Donglin Li,Xianjia Chen,Dingfeng Jin,Hongxiao Jin

To improve the gas sensitivity of reduced oxide graphene (rGO)-based NO2room-temperature sensors, different contents (0–3 wt%) of rGO, ZnO rods, and noble metal nanoparticles (Au or Ag NPs) were synthesized to construct ternary hybrids that combine the advantages of each component. The prepared ZnO rods had a diameter of around 200 nm and a length of about 2 μm. Au or Ag NPs with diameters of 20–30 nm were loaded on the ZnO-rod/rGO hybrid. It was found that rGO simply connects the monodispersed ZnO rods and does not change the morphology of ZnO rods. In addition, the rod-like ZnO prevents rGO stacking and makes nanocomposite-based ZnO/rGO achieve a porous structure, which facilitates the diffusion of gas molecules. The sensors’ gas-sensing properties for NO2were evaluated. The results reveal that Ag@ZnO rods-2% rGO and Au@ZnO rods-2% rGO perform better in low concentrations of NO2gas, with greater response and shorter recovery time at the ambient temperature. The response and recovery times with 15 ppm NO2were 132 s, 139 s and 108 s, 120 s, and the sensitivity values were 2.26 and 2.87, respectively. The synergistic impact of ZnO and Au (Ag) doping was proposed to explain the improved gas sensing. The p-n junction formed on the ZnO and rGO interface and the catalytic effects of Au (Ag) NPs are the main reasons for the enhanced sensitivity of Au (Ag)@ZnO rods-2% rGO.Keywords:Au nanoparticles;Ag nanoparticles;rGO;ZnO rods;p-n junction;synergistic effect

In Situ Growth of Oxygen Defect-Rich Ultrathin WO3 Nanosheets for Ultrafast Recovery NO2 Sensors

Yanghai Gui,Linlin Qian,Kuan Tian,Jintao Wu,Yuansheng Tu,Xiaoyun Qin,Xiaomei Qin

Construction of Cu2O@Cu1.75S Core-shell Octahedrons for Enhanced NO2 Gas Sensing at Low Temperature

Xiaohui Zhang,Ping Li,Ziwei Zhang,Jinghan Guo,Zhongying Fang,Shemsu Ligani Fereja,Kaifan Liu,Xinjie Tong,Yue Zheng,Zongjun Li,Wei Chen

In this work, fabrication of Cu 2 O@Cu 1.75 S core-shell octahedrons was achieved through a facile water bath stirring process. Compared with pure Cu 2 O, the composite showed enhanced sensing performance for NO 2 . The response value of Cu 2 O@Cu 1.75 S to 5 ppm NO 2 at 40 °C is seven times that of Cu 2 O to 5 ppm NO 2 at 75 °C. Moreover, Cu 2 O@Cu 1.75 S has the ability to detect 100 ppb NO 2 and has good NO 2 sensing selectivity and long-term stability. This study shows that Cu 2 O@Cu 1.75 S hybrid is a type of outstanding NO 2 gas sensing material on account of its low working temperature and high sensing sensitivity.

High surface area ZnO/rGO aerogel for sensitive and selective NO2 detection at room temperature

Meiyu Yuan,Changxin Peng,Junjie Fu,Xuening Liu,Zihan Wang,Shiyu Xu,Sheng Cui

Accurate and convenient detection of nitrogen dioxide (NO 2 ) in the air, which is harmful to human health, is vital. However, it is difficult for many NO 2 detection devices to achieve high sensitivity at room temperature. In this work, we synthesized zeolite-imidazolate-frameworks-8 (ZIF-8) nanoparticles and zinc oxide/reduced graphene oxide (ZnO/rGO) aerogel by low-temperature synthesis and sol-gel method. The aerogel composite materials were investigated by X-ray diffractometer (XRD), scanning electron microscopy (SEM), Brunaue-Emmette-Teller (BET), and Raman spectroscopy . The gas-sensitive element prepared by the material with the mass ratio ZIF-8 to rGO is 5:1 possesses excellent selectivity and higher sensitivity (3.21) to 100 ppm NO 2 at room temperature. Reduced graphene oxide (rGO) provides more gas transmission and diffusion channels for improving sensitivity because of a three-dimensional porous structure. When NO 2 is exposed, electrons transfer into p-n heterostructure formed by rGO and ZnO composite to achieve the purpose of sense. In this study, the material preparation method is relatively simple and efficient, which is of profound significance to accurately detect the variation of NO 2 concentration in air at room temperature.

Light-enhanced NO2 sensing performance and sensing mechanism of flower-like Cl uniformly doped In2O3

Huishuang Jiang,Yang Qu,Xianfa Zhang,Rui Gao,Xiaoli Cheng,Shan Gao,Lihua Huo,Zolt́an Major,Yingming Xu

As a poisonous and harmful gas, NO 2 , is not only harmful to the environment, but also detrimental to human health. In this work, ionic liquids (1-hexadecyl-3-methylimidazolium chloride [C 16 Mim] Cl) were selected as dopants to prepare flower-like Cl uniform doped In 2 O 3 nanomaterials. The material exhibits excellent sensing performance to NO 2 under UV light because of Cl uniform doped. Compared with the experiment in dark conditions, the response value of the sensor to 5 ppm NO 2 under UV light is approximately two times higher (S = 425.9) and presents a faster recovery rate (69 s). Chlorine doping shifts the valence band of the material upwards, facilitating the photogenerated electron leap under UV illumination. Moreover, the in-situ DRIFT under UV light were employed to verify the interaction between the materials and NO 2 gas in N 2 , air and O 2 atmospheres respectively. It was found that the presence of oxygen in the environment affects the adsorption of NO 2 on the surface of the Cl doped In 2 O 3 material. This work is of great significance to the sensing mechanism investigation of photo-activated NO 2 gas sensors.

Detection of Ppb-level NO2 using mesoporous ZnSe/SnO2 core-shell microspheres based chemical sensors

Wei Liu,Ding Gu,Xiaogan Li

Detection of ultralow concentrations of the hazardous gases is the major demand and challenge for the development of biosensors. A novel mesoporous ZnSe-core/SnO 2 -shell microspheres based chemiresistive-type sensor was fabricated for ppb-level NO 2 detection, and the theoretical detection limit is calculated to be 0.87 ppb. The as-fabricated sensor presents an excellent performance for low-concentrations of NO 2 up to 2.4 ppm and exhibits significantly higher response approximately 6.94 than those of pristine SnO 2 (∼2.86) and ZnSe based sensors (almost no response) to 2.4 ppm NO 2 at 160 °C. The response and recovery time of the core-shell microspheres based sensor are 64 s and 52 s, respectively, which are substantially improved compared to those of the pristine SnO 2 based sensor (∼149 s and ∼133 s). The sensor demonstrates a superior long-term stability with a deviation in the response of the sensor less than 5 % for one month, and a brilliant selectivity to several possible interferents. The significantly improved sensing performance could be attributed to the obtained mesoporous structures and the formed ZnSe/SnO 2 hybrid interfaces. It yields more active sites and promotes the electrons transferred between ZnSe and SnO 2 nanocrystals. The density functional theory (DFT) calculations are employed to reveal the potential transducing mechanisms.