High-Performance Wearable Sensor Inspired by the Neuron Conduction Mechanism through Gold-Induced Sulfur Vacancies

Liu

et al. 2022

ACS Appl. Nano Mater.

Continuous monitoring of volatile organic compounds (VOCs) is an important challenge for human beings. Allinorganic halide perovskites (AIHPs) have attracted extensive attention because of their excellent semiconductor properties. Perovskite interfacial modulation engineering is considered as a key factor in the preparation of stable and high-performance AIHP devices. In this work, organic hydrophilic ligand 3-mercaptopropionic acid (MPA) is creatively introduced to regulate the nanostructure of CsPbBr 3 and construct the ambient stable binary heterojunction of CsPbBr 3 nanoparticles (NPs)/ZnO NPs. The microscopic morphology design shows that CsPbBr 3 NPs with the optimal nano size have abundant sensitive gas adsorption sites and large specific surface area, which can effectively improve the sensitivity of the CsPbBr 3 -based sensor to ethanolamine (EA). Moreover, hydrophilic groups in MPA are good for the formation of hydrogen bonds and MPA network structures, which effectively improve the binding affinity of metal oxides on MPA surfaces, enhancing the stable anchoring of ZnO to halide perovskite CsPbBr 3 and the heterojunction construction of CsPbBr 3 /ZnO. The CsPbBr 3 -2MPA/ZnO sensor displays the advantages of the lowest theoretical detection limit (DL, 31 ppb), excellent selectivity, a much shorter response time (50 s) than CsPbBr 3 , and significantly enhanced EA response (13.25, 100 ppm) at room temperature, besides the stable repeatability in more than 1 month. In addition, we propose a feasible sensing mechanism. The gas sensor based on CsPbBr 3 /ZnO nano-heterojunctions with efficient hydrophilic MPA modulation may provide constructive idea for the detection of VOCs.

Section: Resultsmentioning

confidence: 99%

Ambient Stable CsPbBr₃/ZnO Nanostructures for Ethanolamine Sensing

Liu

et al. 2022

ACS Appl. Nano Mater.

“…Alternatively, subtle heterojunction construction has been adopted as another effective strategy to promote the gas-sensing performance. − Recently, CuO combined with n -type metal oxides such as WO 3 , SnO 2 , and ZnO , had exhibited a remarkable sensitization effect on H 2 S detection. Also, tungsten disulfide (WS 2 ) as a typical representative of two-dimensional (2D) transition metal dichalcogenides (TMDs) expressed a similar function when in partnership with metal oxides for gas sensing.…”

Section: Introductionmentioning

confidence: 99%

Mesoporous WS₂-Decorated Cellulose Nanofiber-Templated CuO Heterostructures for High-Performance Chemiresistive Hydrogen Sulfide Sensors

Zhao

et al. 2022

Anal. Chem.

There is a great demand to develop high-performance hydrogen sulfide (H 2 S) sensors, especially at the trace level for environmental protection, human healthcare, and food freshness monitoring. To this end, cellulose nanofiber (CNF)templated CuO (CuO-C) was decorated with tungsten disulfide (WS 2 ) nanosheets (W-Cu-C) as the sensing layer of chemiresistive microelectromechanical system (MEMS) sensors for H 2 S recognition in this work. As compared to pristine CuO counterparts at 160.5 °C, the as-prepared W-Cu-C-10 sensors delivered a 30-fold enhanced response of 37 toward 0.5 ppm H 2 S at a lower optimal operation temperature of 100.1 °C. Moreover, a fast response/ recovery speed of 37.2/33.9 s toward 0.5 ppm H 2 S and excellent long-term stability and selectivity were achieved. Compared with existing research and commercial products, the W-CU-C-10 sensors exhibited the remarkable superiorities of high sensitivity, the lowest detection limit of 200 ppb, and ultralow power consumption (8 mW). Also, the sensor showcased a nice on-site application potential for evaluating eggs' freshness. The proposed W-Cu-C-10 sensors probably pave a new avenue for designing high-sensitivity and energy-efficient future H 2 S sensors, especially in the fields of portable and wearable detection systems as well as Internet of Things.

“…In the semiconductor-based gas sensors, defect engineering is a feasible and effective technique to adjust the physicochemical properties of nanomaterials. , First-principles calculations have showed that S-defected SnS 2 exhibits ideal adsorption for CO and C 2 H 2 molecules, suggesting that the vacancy could significantly enhance the chemical reactivity of the gas with the substrate. , Besides, the gas-sensing features could be improved by introducing noble metals to modify the sensitive layer because of spillover effect and electron sensitization effect, which results in an increase in the sensitivity of the sensor. − For example, the response of Ag nanoparticle-embedded-ZnO nanorod sensors to 50 ppm ethanol was increased by a factor of 3 compared to the pure-ZnO nanorods . Therefore, it is assumed that further studies on the synergy of the two strategies to enhance the ethanol-sensing performance of pure SnS 2 will be promising.…”

Section: Introductionmentioning

confidence: 99%

“…21,22 First-principles calculations have showed that S-defected SnS 2 exhibits ideal adsorption for CO and C 2 H 2 molecules, suggesting that the vacancy could significantly enhance the chemical reactivity of the gas with the substrate. 23,24 Besides, the gas-sensing features could be improved by introducing noble metals to modify the sensitive layer because of spillover effect and electron sensitization effect, which results in an increase in the sensitivity of the sensor. 25−27 For example, the response of Ag nanoparticle-embedded-ZnO nanorod sensors to 50 ppm ethanol was increased by a factor of 3 compared to the pure-ZnO nanorods.…”

Section: Introductionmentioning

confidence: 99%

S-Vacancies and Ag Nanoparticles in SnS₂ Nanoflakes for Ethanol Sensing: A Combined Experimental and Theoretical Investigation

Qiu

Qin

2022

ACS Appl. Nano Mater.

In recent years, the potential of two-dimensional layered metal dichalcogenides for gas-sensing applications has been explored. Both defect engineering and noble metal modification are powerful strategies to achieve higher gas sensitivity. In this paper, a combined experimental and theoretical study on a SnS2-based sensor is performed to demonstrate the effect of individual or cooperative modulation of S-vacancy (Vs) defect and Ag nanoparticles (nano-Ag) on its gas-sensing performance. Gas-sensing measurements indicate that Ag/Vs-SnS2 shows the strongest response upon exposure to ethanol and a response as high as 94.7% when the ethanol concentration was 15 ppm. Especially, the limit of detection value of Ag/Vs-SnS2 calculated based on the low concentration response data is 2.12 ppb, implying its ultra-sensitive characteristic to ethanol vapor. Meanwhile, the response time and recovery time to 5 ppm ethanol are 7 and 45 s, respectively, and the response error is about 1.8%. It is clarified theoretically that both Vs modulation and Ag modification could enhance the adsorption strength of ethanol molecules on the SnS2 surface, and the SnS2 with co-modification of Vs and nano-Ag (Ag/Vs-SnS2) exhibits the strongest adsorption for the ethanol molecule. The potential mechanism for the enhanced response of nano-Ag/Vs-SnS2 was also further analyzed and demonstrated. This work provides an efficient strategy for developing high-quality gas sensors capable of sensitively detecting ethanol at room temperature.