H₂S Detection by Vertically Aligned CuO Nanowire Array Sensors

Abstract

Chemical sensors based on vertically aligned p-type CuO nanowire arrays have been fabricated by in situ micromanipulation in a scanning electron microscope. The sensors are capable of detecting air-diluted H 2 S to the parts per billion level. Different mechanisms have been proposed for the detections of low and high concentrated H 2 S. The recoverable detection for low concentrations can be explained by an oxygen adatom related process, while an interface reaction model fits for the high concentration detection, which also explains the exponential sensing response. Furthermore, selective detection for H 2 S has also been investigated. The sensor demonstrated strong selectivity for H 2 S, as compared with the responses to high concentrations of H 2 , CO, and NH 3 .

Copper (II) oxide nanowires for p-type conductometric NH3 sensing

“…Recently, the potential of CuO nanowires as building-blocks of new devices has been pointed out [10][11][12][13][14]. Among the different techniques to synthesize CuO nanowires, such as electro-spinning [17] and template-assisted growth [11], the direct oxidation of Cu foils [14][15][16] is easy to implement and scalable, providing pleasing results in terms of crystallinity and material quality [14].…”

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

“…The increase in gas response at the operating temperatures from 30 o C to 350 o C could be attributed to the fact that the obtained thermal energy was in favor of overcoming the activation energy barrier for the surface chemical reactions between H 2 S molecules and absorbed oxygen species, causing the significant increase of response of gas sensor to H 2 S [34][35][36]. However, when the operating temperature was above 350 o C, the H 2 S gas was consumed within a very shallow surface of the sensing layer, therefore, the utilization rate of the sensing layer was decreased, thus the diffusion depth of the H 2 S gas was decreased [34][35][36].…”

“…However, when the operating temperature was above 350 o C, the H 2 S gas was consumed within a very shallow surface of the sensing layer, therefore, the utilization rate of the sensing layer was decreased, thus the diffusion depth of the H 2 S gas was decreased [34][35][36]. Accordingly, the resistance of sensor was decreased.…”

Synthesis of Vertically Aligned CuO Nanorods by Thermal Oxidation

“…그 중 나노선 구조는 여러가지 물질을 나노단위 두께의 선형태로 성장시킨 구조로써, 표면적이 크다는 구조적인 특성상 센서, [3][4][5][6][7][8][9] 태양전지, 10-12) 의료 [13][14][15][16] …”