Mechanism of Optical and Electrical H2S Gas Sensing of Pristine and Surface Functionalized ZnO Nanowires
Year: 2024
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide In this work, the sensing ability and the underlying reaction pathways of H 2 S adsorption on two nanomaterial systems, pristine zinc oxide (ZnO) nanowires (NWs) and gold functionalized zinc oxide nanowires (Au@ZnO NWs), were explored in a side-by-side comparison of optical and electrical gas sensing. The properties of optical sensing were analyzed by photoluminescence intensity-over-time measurements ( PL - t ) of as-grown ZnO NW samples, and the electrical gas-sensing properties were analyzed by current-over-time measurements ( I - t ) of ZnO NW chemically sensitive field-effect transistor (ChemFET) structures with a gas-sensitive open gate. The ZnO NWs were grown by high-temperature chemical vapor deposition (CVD) and thereafter surface-functionalized with a thin Au nanoparticle layer by magnetron sputtering. Detailed X-ray photoelectron spectroscopy (XPS) analysis, alongside an experimental estimation of activation energies ( E A ) involved in the H 2 S sensing process, and the application of a simple analytical test allowed us to propose a complete picture of the sensing mechanism on the pristine ZnO surface and the Au@ZnO surface. The combined results hint at H 2 S dissociation via surface interaction and irreversible adsorption dynamics for both material systems occurring already at room temperature. Our findings specifically emphasize the impact of Au functionalization morphology on sensor sensitivity and the beneficial importance of chemical affinity between Au and H 2 S for superior H 2 S sensing results, aiming at enhanced response and selectivity for potential medical H 2 S detection in human breath.
Source: ACS Omega
Institution: Universität Ulm
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,935
Funder: Deutsche Forschungsgemeinschaft
OpenAlex ID: W4405333328