A Highly Sensitive and Room Temperature CNTs/SnO2/CuO Sensor for H2S Gas Sensing Applications

Abstract

Gas sensors based on tin dioxide-carbon nanotube composite films were fabricated by a simple inexpensive sol-gel spin-coating method using PEG400 as a solvent. Nanostructured copper was coated on CNTs/SnO 2 film, and then copper was transformed into copper oxide at 250°C. Resistivity of the final composite films is highly sensitive to the presence of H 2 S, which became easily attached or detached at room temperature. The response and recovery time of the sensor are 4 min and 10 min, and the value of sensitivity is 4.41, respectively. Meanwhile, the CNTs/SnO 2 /CuO sensor also has low detection limit, high selectivity toward H 2 S, and stable performance with different concentrations of H 2 S.

1D Metal Oxide Semiconductor Materials for Chemiresistive Gas Sensors: A Review

“…Like noble metal doping, the nanocomposites of MOS‐based sensing materials also lead to enhancing gas sensing performance. Heterojunction of MOS/MOS, [ 47,61,105,125,235,274–285 ] MOS/TMDs, [ 241–243,286 ] and MOS/carbon‐based materials [ 224,225,228,230,247,287–291 ] have been widely reported in the past few decades. In general, due to the different semiconducting properties, the sensing mechanism of heterojunctions and homojunctions is different.…”

“…CNTs that perform either metallic or semiconducting properties have also been used as sensing materials for decades. [ 41,288,307–310 ] Due to the different electronic property of CNTs and the theory which explained enhanced gas sensitivity of MOS‐based nanocomposites, the gas sensing performance of CNT‐MOS would be enhanced. Therefore, many researchers have tried to synthesize the composites of these CNT/graphene and MOS for demonstrating an enhanced gas sensing performance.…”

Highly responsive and selective ppb-level NO2 gas sensor based on porous Pd-functionalized CuO/rGO at room temperature

“…As an important p-type semiconductor, cupric oxide (CuO) has been extensively studied to detect toxic and flammable gases owing to its non-toxicity, low cost and facile synthesis. 5,6 Kim et al reported a networked CuO nanowire grown on patterned-electrode pads by the thermal oxidation of Cu layers for detecting NO 2 gas, which displayed a gas-sensing response of about 55% towards 10 ppm NO 2 gas at an operational temperature of 300 1C, and a response time of 100 s and recovery time of 200 s were also recorded. 7 Navale et al designed CuO thin films on a quartz substrate using a simple and catalyst-free thermal evaporation technique for sensing NO 2 gas, exhibiting the maximum response value of 76% towards 100 ppm NO 2 gas at the operation temperature of 150 1C, and the LOD was only 1 ppm.…”

Nanomaterials-Based Resistive Sensors for Detection of Environmentally Hazardous H2S Gas

“…Many studies have shown that CNTs play a major role as potential dopants of SnO 2 . Zhao et al 188 have synthesized CNTs/SnO 2 composite film using sol-gel followed by the CuO being coated by a vacuum evaporation method. The CNTs/SnO 2 /CuO film shows high sensitivity (S = R a À R c )/(DC = 4.41) and fast response and recovery times as compared to SnO 2 and SnO 2 /CuO nanocomposites.…”