# Structural design and temperature control enabling high sensitivity nanomaterial-based three-electrode gas sensors

## TL;DR

This paper introduces a new gas sensor design using nanomaterials that improves sensitivity and reduces ion bombardment effects.

## Contribution

A novel sensor structure with a diffusion aperture and nanostructured cathode is proposed to enhance gas detection performance.

## Key findings

- The sensor design reduces positive ion bombardment by maintaining a high reverse electric field around cathode nanotips.
- The new sensor shows three times greater sensitivity to gases like H2, C2H2, and SO2 compared to previous designs.
- Detection ranges are improved down to ppm, ppb, and ppt levels.

## Abstract

Ionization based gas sensors using nanomaterials hold significance in monitoring gases but often suffer from issues such as excessive positive ion bombardment, which reduces lifespan, current collection, and detection accuracy. This study introduces a two-dimensional plasma discharge current model based on particle mass conservation, electron energy conservation, and Poisson equations to evaluate the discharge characteristics and electric fields distribution effects on sensor performance across various morphologies and cathode nanomaterial quantities, with experimental validation. The results indicated that the diffusion aperture diameter structure adjustment in sensor electrode surface maintains a high reverse electric field E1 around the nanotips of the cathode, accelerated maximum positive ions away from nanomaterial, which reduces positive ion bombardment. The novel Φ = 1.2 × 9 mm diffusion aperture sensor with a 150 nm gold nanostructured cathode effectively directed approximately ~ 2/3 of positive ions from the ionization to the collection region, mitigating corrosion and bombardment effects. Compared to previous structure, this novel sensor shows three times greater sensitivity to H2, C2H2, CH4, SO2, NO, and O2, with enhanced detection ranges down to ppm, ppb, and ppt levels.

The online version contains supplementary material available at 10.1038/s41598-024-76678-2.