Enhanced gas sensing in pristine carbon nanotubes under continuous ultraviolet light illumination
نویسندگان
چکیده
The advance of nanomaterials has opened new opportunities to develop ever more sensitive sensors owing to their high surface-to-volume ratio. However, it is challenging to achieve intrinsic sensitivities of nanomaterials for ultra-low level detections due to their vulnerability against contaminations. Here we show that despite considerable achievements in the last decade, continuous in situ cleaning of carbon nanotubes with ultraviolet light during gas sensing can still dramatically enhance their performance. For instance in nitric oxide detection, while sensitivity in air is improved two orders of magnitude, under controlled environment it reaches a detection limit of 590 parts-per-quadrillion (ppq) at room temperature. Furthermore, aiming for practical applications we illustrate how to address gas selectivity by introducing a gate bias. The concept of continuous in situ cleaning not only reveals the tremendous sensing potential of pristine carbon nanotubes but also more importantly it can be applied to other nanostructures.
منابع مشابه
Enhanced Sensitivity of MoTe2 Chemical Sensor through Light Illumination
Two-dimensional (2D) transition metal dichalcogenides (TMDCs) semiconducting materials have recently attracted wide attention and been regarded as promising building blocks for chemical sensors due to their high surface-to-volume ratio. However, their low response hinders the realization of high-performance 2D TMDCs chemical sensors. Here, we demonstrate the improvement of sensing performance o...
متن کاملPhotoconductivity of single-wall carbon nanotubes under continuous-wave near-infrared illumination
The photoconductivity of films of single-wall carbon nanotubes has been studied under continuous-wave near-infrared illumination. The photocurrent exhibits a linear response with the light intensity and with bias voltage up to 5 V. The temporal photoresponse of on/off step illumination shows a relatively slow relaxation time ~4.3 s for films with a thickness of ;500 nm!, which can be interprete...
متن کاملUV Light Activation of TiO2-Doped SnO2 Thick Film for Sensing Ethanol at Room Temperature
TiO2-doped SnO2 nanopowder is synthesized via a sol-gel method and characterized by atomic force microscopy and X-ray diffraction. Using this nanopowder, we have fabricated a novel semiconductor gas sensor that is sensitive to UV light illumination. We find that gas-sensing properties of TiO2-doped SnO2 sensor can be enhanced significantly under the exposure of UV light. The sensor exhibits a h...
متن کاملUV ENHANCEMENT OF THE GAS SENSING PROPERTIES OF NANO-TiO
In this study, the gas-sensing properties of nanocrystalline TiO 2 are enhanced by submitting the sensor system to UV light irradiation. TiO 2 gas sensing material based on nanosized particles is produced by gas condensation method. The crystal structure and ceramic microstructure of the powders are determined by TEM and XRD. Structural and morphological studies as well as UV irradiation are ca...
متن کاملElectrochemical Sensing of H2S Gas in Air by Carboxylated Multi-walled Carbon Nanotubes
The electrochemical sensor for detecting hydrogen sulfide was fabricated. H2S gas molecules pass through polytetrafluoroethylene membrane with 0.22 mm pore size. Carboxylated multi-walled carbon nanotubes (MWCNTs-COOH) were used to fabricate working and counter electrodes. It can be seen from Field Emission Scanning Electron Microscopy (FESEM) images of the working electrode that...
متن کامل