CuO Nanosheets for Sensitive and Selective Determination of H₂S with High Recovery Ability

Abstract

In this article, cupric oxide (CuO) leafletlike nanosheets have been synthesized by a facile, low-cost, and surfactant-free method, and they have further been successfully developed for sensitive and selective determination of hydrogen sulfide (H 2 S) with high recovery ability. The experimental results have revealed that the sensitivity and recovery time of the present H 2 S gas sensor are strongly dependent on the working temperature. The best H 2 S sensing performance has been achieved with a low detection limit of 2 ppb and broad linear range from 30 ppb to 1.2 ppm. The gas sensor is reversible, with a quick response time of 4 s and a short recovery time of 9 s. In addition, negligible responses can be observed exposed to 100-fold concentrations of other gases which may exist in the atmosphere such as nitrogen (N 2 ), oxygen (O 2 ), nitric oxide (NO), cabon monoxide (CO), nitrogen dioxide (NO 2 ), hydrogen (H 2 ), and so on, indicating relatively high selectivity of the present H 2 S sensor. The H 2 S sensor based on the CuO nanosheets also shows strong recovery ability and long-term stability, probably due to the effective diffusion of gas toward the whole sensing surface, as well as the different mechanism of H 2 S gas sensor from those reported at CuO nanowires and CuO-SnO 2 nanocomposites, where a layer of CuS or Cu 2 S has formed on the CuO surface.

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

“…Again, the sensing mechanism of this reducing gas was explained by the interaction with the oxygen species at the CuO surface. Water and sulphur dioxide were identified as the main resulting products [7],…”

“…In this latter application, films of CuO were reported to detect O 3 , CO and C 5 H 2 OH among other chemical species [7][8][9]. Recently, the potential of CuO nanowires as building-blocks of new devices has been pointed out [10][11][12][13][14].…”

The Assembly and Fabrication of Single CuO Nanowire Electronic Device Based on Controllable DWS-DEP Technology

“…Several groups had studied on CuO nanowires-based gas sensors, such as H 2 S sensor [9], [10], [13], humidity sensor [6], [12], but those sensors are based on CuO nanowires arrays and they still work at high temperature. Here our single CuO nanowire alcohol sensor can work at room temperature.…”

“…When the single CuO nanowire is exposed to N 2 again, the current recovers to nearly its initial value. Compared to the nanowires arrays based sensors working only at high temperature [6], [9], [10], [12], [13], the single nanowire alcohol sensor can work at room temperature with the reasons probably as follows. In those sensors based on nanowires arrays, the CuO nanowires are protruded from relatively thick CuO substrate through which the detected current passes.…”

Large-scale assembly of Cu/CuO nanowires for nano-electronic device fabrication

“…It has been shown that CuO can be used in high temperature superconductors, magnetic storage media, gas sensor, field emitters and heterogeneous catalysis, and so on [4]. The CuO nanowires based sensors can take advantage of testing many objects, such as NO 2 [5], H 2 S [6], pH [7], humidity [8], glucose [9], etc.…”