Science Inventory

ZnO Functionalization of Multi-walled Carbon Nanotubes for Methane Sensing at Single Parts Per Million Concentration Levels

Citation:

Humayun, M., R. Divan, L. Stan, A. Gupta, D. Rosenmann, L. Gundel, P. Solomon, AND I. Paprotny. ZnO Functionalization of Multi-walled Carbon Nanotubes for Methane Sensing at Single Parts Per Million Concentration Levels. Journal of Vacuum Science & Technology B. American Institute of Physics, NEW YORK, NY, 33(6):1-7, (2015).

Impact/Purpose:

The National Exposure Research Laboratory’s (NERL’s) Human Exposure and Atmospheric Sciences Division (HEASD) conducts research in support of EPA’s mission to protect human health and the environment. HEASD’s research program supports Goal 1 (Clean Air) and Goal 4 (Healthy People) of EPA’s strategic plan. More specifically, our division conducts research to characterize the movement of pollutants from the source to contact with humans. Our multidisciplinary research program produces Methods, Measurements, and Models to identify relationships between and characterize processes that link source emissions, environmental concentrations, human exposures, and target-tissue dose. The impact of these tools is improved regulatory programs and policies for EPA.

Description:

This paper presents a novel atomic layer deposition (ALD) based ZnO functionalization of surface pre-treated multi-walled carbon nanotubes (MWCNTs) for highly sensitive methane chemoresistive sensors. The temperature optimization of the ALD process leads to enhanced ZnO nanoparticle functionalization and improvement in their crystalline quality as shown by energy dispersive X-Ray (EDX) and Raman spectroscopy. The behavior of ZnO-MWCNT sensor in presence of down to two ppm level methane concentrations in dry air has been compared with that of pristine MWCNT based sensor demonstrating that ZnO functionalization is an essential factor behind the highly sensitive chemoresistive nature of the ZnO-MWCNT heterostructures. The sensor is currently being tested under a range of conditions that include potentially interfering gases and changes to relative humidity (RH).

Record Details:

Record Type:DOCUMENT( JOURNAL/ PEER REVIEWED JOURNAL)
Product Published Date:10/27/2015
Record Last Revised:11/02/2015
OMB Category:Other
Record ID: 310043