A high performance hydrogen sulfide gas sensor based on porous α-Fe2O3 operates at room-temperature

ACS Appl. Mater. Interfaces

Lin

et al. 2016

Self Cite

239

109

Porous CuO nanosheets were prepared on alumina tubes using a facile hydrothermal method, and their morphology, microstructure and gas sensing properties were investigated. The monoclinic CuO nanosheets had an average thickness of 62.5 nm and were embedded with numerous holes with diameters ranging 5 nm to 17 nm. The porous CuO nanosheets were used to fabricate gas sensors to detect hydrogen sulfide (H 2 S) operated at room temperature. The sensor showed a good response sensitivity of 1.25 with the respond/recovery time of 234 s and 76 s, respectively, when tested with the H 2 S concentrations as low as 10 ppb. It also showed a remarkably high selectivity to the H 2 S, but only minor responses to other gases such as SO 2 , NO, NO 2 , H 2 , CO and C 2 H 5 OH. The working principle of the porous CuO nanosheets based sensor to detect the H 2 S was identified to be the phase transition from semiconducting CuO to a metallic conducting CuS.

Section: Structural Characterizationmentioning

confidence: 90%

Section: Manufacture and Testing Of Gas Sensormentioning

confidence: 99%

Section: Manufacture and Testing Of Gas Sensormentioning

confidence: 99%

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Room-Temperature High-Performance H₂S Sensor Based on Porous CuO Nanosheets Prepared by Hydrothermal Method

ACS Appl. Mater. Interfaces

Lin

et al. 2016

Self Cite

239

109

“…Changes of resistance of the gas sensor were measured using a source meter (Keithley 2400) and the data were collected using a Lab-view software. The respond (R) of the sensor is defined as follows: R=Ra/Rg, where the Rg and Ra are the resistance of the sensor in H 2 S gas and air, respectively [30]. Furthermore, the crystallite grain size of the α-Fe 2 O 3 was estimated to be 152.8 nm according to the Scherrer formula:…”

Section: Gas Sensor Fabrication and Measurementsmentioning

confidence: 99%

“…Many α-Fe 2 O 3 nanostructures with various morphologies have been synthesized, including nanowires [19], nanorods [20,21], nanobelt [22], nanofiber [23,24], nanospheres [25], nanotubes [26][27][28] and porous α-Fe 2 O 3 [29,30]. However, it is still a big challenge to find a facile preparation technique for the α-Fe 2 O 3 with special morphologies in order to achieve excellent gas sensing properties, such as good response, short response/recovery time, good long-term stability and selectivity.…”

Section: Introductionmentioning

confidence: 99%

Facile synthesis of α-Fe2O3 micro-ellipsoids by surfactant-free hydrothermal method for sub-ppm level H2S detection

Lin

et al. 2016

Materials & Design

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The α-Fe 2 O 3 micro-ellipsoids were prepared using a facile hydrothermal process without any surfactant or template, and their morphological, structural and H 2 S sensing properties were investigated.The α-Fe 2 O 3 showed uniform micro-ellipsoids with a long axis diameter of 1.7 µm and a short axis diameter of 1.2 µm. Detailed structural analysis confirmed that the synthesized α-Fe 2 O 3 micro-ellipsoids were compact particles with a hexagonal structure. Gas sensor base on the α-Fe 2 O 3 micro-ellipsoids showed excellent response, short response/recovery time (less than 90 s and 30 s, respectively), low detection concentration (~0.5 ppm), good long-term stability and excellent selectivity towards H 2 S gas at the optimized operating temperature of 350 o C. The sensing mechanism of the sensor based on the α-Fe 2 O 3 micro-ellipsoids towards H 2 S was discussed.

Highly Sensitive Long‐Wave Infrared Photodetector Based on Two‐Dimensional Hematite α‐Fe₂O₃

Advanced Optical Materials

Liu

Cao

et al. 2023

Ambient temperature long‐wavelength infrared (LWIR) photodetection has many critical applications ranging from thermal imaging and optical communications to night vision cameras. Currently, high performance, low cost, air stability, and ultra‐broadband response still constitute challenges. Here, the study demonstrates a high‐performance uncooled LWIR photodetector using 2D hexagonal α‐Fe2O3 single crystal nanoflakes, which are synthesized via chemical vapor deposition. The 2D α‐Fe2O3 photodetector realizes high specific detectivity (D*) of 3.28×109 cmHz1/2 W−1 and very low noise equivalent power of 8.94×10−14 W Hz−1/2 with 10.6 µm laser. The photo bolometer effect is responsible for the photoresponse in the infrared range with a large temperature coefficient resistance of −241.2% K−1. This study shows a new type of potential broadband response material and provides a promising LWIR optoelectrical device with good air stability.