查找使用阿拉丁产品的科研文献

Construction of WO3/InWO4 heterojunction for NO2 detection at room temperature under UV activation

Zhihua Ying,Yi Zhong,Yan Liu,Wenjun Yan

Background Nitrogen dioxide (NO 2 ) is a hazardous atmospheric pollutant, driving demand for highly sensitive and reliable monitoring sensors. A significant challenge in this field is enhancing the performance of metal-oxide-based gas sensors, particularly their response and operating temperature. Current materials often exhibit insufficient sensitivity at room temperature, limiting their practical application. This work addresses the problem of developing a high-performance NO 2 gas sensor that operates effectively at room temperature. Results We present a novel WO 3 /InWO 4 heterojunction sensor that demonstrates dramatically enhanced NO 2 sensing under UV activation. The key result is a response value of 116.03 to 3 ppm NO 2 at room temperature, which is 3.55 times higher than that of a pure InWO 4 sensor. The composite sensor showed a response time of 68 s and a recovery time of 43 s, representing a slight increase and decrease, respectively, compared to the pure material. This performance is attributed to the synergistic effects of the constructed heterojunction, which promotes charge separation, alongside optimized oxygen vacancy concentration and UV light activation. The method was comprehensively validated through material characterization and gas-sensing tests, confirming that this composite structure effectively improves surface reactions with NO 2 molecules. Significance This study conclusively demonstrates that the WO 3 /InWO 4 heterojunction strategy is highly effective for NO 2 sensing. The significance lies in achieving exceptional sensor response at room temperature, providing a valuable pathway for developing low-power, high-performance gas sensing devices.

Dual-mode MWCNTs-InSe sensor for temperature/NO2 detection: Wearable and system-level application

Mingyang Gao,Bohang Zhang,Yutian Ma,Xinyuan Du,Chunxue Zhai,Zhiyong Zhang,Wu Zhao

Simultaneous monitoring of temperature and gas concentration is crucial in many practical scenarios, as these two parameters are often strongly coupled. However, conventional sensing platforms typically rely on multiple single-function sensors, increasing system complexity and limiting their applicability. In this work, we first develop a rigid multi-wall carbon nanotubes (MWCNTs)‑indium selenide (InSe) sensor with excellent dual-mode temperature and nitrogen dioxide (NO 2 ) sensing capabilities, achieving high thermal sensitivity and ppb-level gas detection. Building on this foundation, a wearable version of the sensor is fabricated, enabling robust performance under mechanical deformation. Finally, the flexible device is integrated into a compact system featuring two independent sensing channels, real-time display, and threshold-triggered alarms. This study demonstrates a simple yet powerful strategy to realize multifunctional environmental sensing with a single sensor unit and highlights its strong potential for next-generation wearable electronics and intelligent environmental monitoring.

Para-selective nitration of bromobenzene catalyzed by Hβ zeolite with NO2 and its theoretical studies

Deng Renjie,Zeng Manlin,Tian Yao

A novel heterogeneous catalytic system was developed for the preparation of para -nitrobromobenzene ( p -NBr) with nitrogen dioxide (NO 2 ) as nitrating agent in the presence of oxygen (O 2 ). By applying Hβ zeolite as the catalyst, p -NBr can be obtained with high conversion (85.7%) and selectivity (91.7%). In addition, it can be recycled at least five times without a significant decrease in catalytic activity, which demonstrates its high efficiency, good stability and regenerability. Meanwhile, DFT study explained the regioselectivity for the nitronium (NO 2 + ) nitration via electrophilic process, which support the experimental conclusion. Graphical abstract

One-Dimensional Bi2S3 Nanobelts-Based Surface Acoustic Wave Sensor for NO2 Detection at Room Temperature

Jingting Luo,Xiaoying Feng,Hao Kan,Hui Li,Chen Fu

Surface acoustic wave (SAW) devices show promising applications for highly sensitive gas sensors for continuously monitoring of hazardous and flammable gases when integrating with specifically designed sensing materials. Improving the SAW sensor's responses by using nanostructure sensing materialshas become a research hot topic in recent years. In this work, we presented a SAW room temperature NO2 gas sensor with high sensitivity using one-dimensional (1D) Bi2S3 Nanobelts as the sensing materials. SAW devices with thecentral frequency of ~200 MHz were fabricated on ST-cut quartz substrate as the sensing platform. The Bi2S3 Nanobelts were synthesized by solvothermal method and deposited onto SAW sensors using a spin-coating technology. The response of the prepared SAW gas sensors was 2 kHz when subjected to 10 ppm NO2 even at room temperature. Moreover, the sensor shows good selectivity, reversibility, and stability. The sensing mechanism of one-dimensional Bi2S3 nanobelts-based SAW sensors for NO2 detection was also be discussed.

Ag/Cu Bimetallic Nanoparticles Loaded on In2O3 for Rapid and Ultrasensitive Room-Temperature NO2 Detection

Yufang Cui,Wanyin Ge,Maohao Yang,Xin Dong,Bochuan Zhang

Breakthrough: Ag/Cu bimetallic sensitization and UV activation enables efficient room-temp NO 2 detection. • High response (2180 to 200 ppm NO 2 ) with fast 7/10   s response/recovery at RT under UV. • High selectivity and moisture resistance, integrated into smart masks for breath-level detection. Metal oxide semiconductor (MOS) NO 2 gas sensors are hindered from achieving high-performance, low-power practical applications due to their slow response/recovery times and excessively high operating temperatures. To overcome these obstacles, we propose a synergistic strategy combining silver/copper (Ag/Cu) bimetallic nanoparticle surface modification with ultraviolet (UV) light activation. Using NH 2 -MIL-68 as a sacrificial template, In 2 O 3 rod-like materials were prepared via a hydrothermal method, and Ag/Cu bimetallic nanoparticles were further decorated on their surface to construct a high-performance NO 2 sensor (Ag/Cu-In 2 O 3 ) capable of operating at room temperature. Under UV light excitation, the Ag/Cu-In 2 O 3 -1 sensor exhibited a high response of 2180 toward 200 ppm NO 2 , with response and recovery times as short as 7   s and 10   s, respectively. Moreover, the sensor showed excellent selectivity for NO 2 against various interfering gases and good humidity tolerance. The enhanced performance is attributed to the synergistic sensitization of Ag/Cu bimetallic nanoparticles and the photogenerated holes induced by UV illumination during response and recovery. This study highlights the potential of Ag/Cu-In 2 O 3 for room-temperature NO 2 sensing and demonstrates the effectiveness of UV excitation in boosting MOS gas sensor performance. Download: Download high-res image (135KB) Download: Download full-size image

One-Step Solvothermal Construction of ZnWO4/ZnO Heterostructures for Enhanced NO2 Sensing at Room Temperature

Luying Wang,Yueting Li,Jing Tang,Xianfa Zhang,Lihua Huo,Yingming Xu,Xiaoli Cheng

Excessive NO 2 emissions not only damage the ecological environment but also endanger human health. Therefore, developing gas sensors for efficient detection of NO 2 gas is essential. In this study, a one-step solvothermal method was used to prepare the ZnWO 4 /ZnO heterostructure for NO 2 detection at room temperature (RT). The ZnWO 4 /ZnO sensors showed an excellent response for NO 2 (174.5/3 ppm) and a low detection limit of 10 ppb at RT. The synergistic interaction between the heterostructure and oxygen vacancies contributes to the superior sensing capability of ZnWO 4 /ZnO heterostructures. The construction of the heterostructure accelerates charge separation and migration, while oxygen vacancies provide abundant active sites and adsorption sites for gas molecules. This work offers a viable strategy for developing highly sensitive ZnWO 4 /ZnO-based gas sensors at RT.

A SnTe/In2S3 heterojunction gas sensor with ppb-level detection of NO2 at room temperature

Baoyu Huang,Haochen Zhang,Zhipeng Guan,Shupeng Sun,Yuwei Shan,Wencheng Ma,Nan Wang,Lingchu Huang,Xiaogan Li

NO 2 is an important component of air pollution and can have a significant impact on the environment and human respiratory health. Therefore, the requirement for real-time detection of low-concentration NO 2 from various emission sources drives the development of a specialized gas sensor. In this work, a heterojunction material based on bulk SnTe and In 2 S 3 nanosheets was developed, which can reach the ppb-level detection of NO 2 at room temperature. The sensor based on SnTe/In 2 S 3 exhibits better response (5.56) and a faster response time (58 s) for 1 ppm of NO 2 compared to the original SnTe-based sensor with the response of 1.11 and the response time of 204 s and reaches the detection limit of 75 ppb. The heterojunction sensor exhibits not only enhanced response and low detection limit but also performs improved selectivity, repeatability and long-term stability. The comprehensive performance enhancements result from both the promoted charge transfer due to the SnTe/In 2 S 3 heterojunction and abundant surface-adsorbed oxygen. The sensing mechanisms were studied through the use of in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and electrochemical impedance spectroscopy.

Dual-sided Pd functionalization of groove-textured CeO2 hollow microcages boosts room temperature NO2 sensing

Yan Tong,Pengkai Xing,Wenbo Ruan,Xiaopeng Wang,Rui Zhang,Weixin Lv,Muhammad Ikram,Xue Bai,Qin Guo,Keying Shi

Room-temperature (RT) detection of NO 2 remains challenging because low-temperature operation often limits surface reactivity and charge-transport modulation. Here, a noble-metal-decorated hollow cage-like oxide is constructed by integrating a template-assisted route with hydrothermal processing, yielding a cauliflower-like architecture with a high specific surface area and abundant, accessible adsorption sites for NO 2 capture. Surface decoration further enriches oxygen vacancies and enhances the oxygen storage capacity, promoting oxygen activation and NO x surface chemistry under ambient conditions. Meanwhile, the formation of a Schottky barrier between Pd and CeO 2 enhances the conductivity and electron mobility of the composite. As a result, the chemiresistive sensor delivers a response of 32.84 toward 100 ppm NO 2 at room temperature, with a 3 s response and 15 s recovery, while maintaining good selectivity, repeatability, and long-term stability. The device further achieves a 30 ppb detection limit, highlighting this hollow, vacancy-rich microcage platform as an effective strategy for low-power NO 2 monitoring. This work provides a generalizable interface and defect engineering strategy for next-generation RT NO 2 sensors.

Pd functionalized MoS2 hierarchical spherical for detection of NO2: A combined experimental and theoretical study

Saisai Zhang,Yi Zheng,Bo Zhang,Bowen Zhang,Na Luo,Yan Wang

Since nitrogen dioxide (NO 2 ) is an air pollutant that can seriously harm human health, developing high-performance gas sensors capable of efficiently detecting nitrogen dioxide at room temperature is of great significance for environmental monitoring and health protection. In this work, we synthesized hierarchical spherical MoS 2 with a high specific surface area via a hydrothermal method and uniformly loaded Pd nanoparticles onto its surface through an in-situ reduction strategy, successfully constructing a Pd/MoS 2 composite material. Characterization techniques including SEM, TEM，XPS confirmed the successful loading of Pd nanoparticles and the electronic interaction between Pd and MoS 2 . Experimental results demonstrate that the 1% Pd/MoS 2 composite exhibits optimal sensing performance toward NO 2 at room temperature: a high response value (Rg/Ra) of 9.33 toward 10 ppm NO 2 , along with excellent selectivity, repeatability, and long-term stability. Density Functional Theory (DFT) calculations further elucidated the enhancement mechanism: the introduction of Pd significantly increased the adsorption energy of NO 2 on the material surface (from −0.253 eV to −1.41 eV), thereby greatly improving the sensor's sensitivity and response kinetics. This research provides an effective material design strategy and theoretical foundation for developing high-performance, low-power-consumption room-temperature NO 2 gas sensors.

Effects of NO2 and SO2 on the secondary organic aerosol formation from β-pinene photooxidation

Xiangyu Zang,Zhaoyan Zhang,Yingqi Zhao,Gang Li,Hua Xie,Weiqing Zhang,Guorong Wu,Xueming Yang,Ling Jiang

Elucidating the effects of anthropogenic pollutants on the photooxidation of biogenic volatile organic compounds is crucial to understanding the fundamental mechanisms of secondary organic aerosol (SOA) formation. Here, the impacts of NO 2 and SO 2 on SOA formation from the photooxidation of a representative monoterpene , β -pinene, were investigated by a number of laboratory studies. The results indicated NO 2 enhanced the SOA mass concentrations and particle number concentrations under both low and high β -pinene conditions. This could be rationalized that the increased O 3 concentrations upon the NO x photolysis was helpful for the generation of more amounts of O 3 -oxidized products, which accelerated the SOA nucleation and growth. Combing with NO 2 , the promotion of the SOA yield by SO 2 was mainly reflected in the increase of mass concentration, which might be due to the elimination of the newly formed particles by the initially formed particles. The observed low oxidation degree of SOA might be attributed to the fast growth of SOA, resulting in the uptake of less oxygenated gas-phase species onto the particle phase. The present findings have important implications for SOA formation affected by anthropogenic–biogenic interactions in the ambient atmosphere.

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

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.