Gas Sensing Properties of Pd-Decorated GeSe Monolayer toward Formaldehyde and Benzene Molecules: A First-Principles...

Area of Science:

• Materials Science
• Nanotechnology
• Computational Chemistry

Background:

• Two-dimensional (2D) materials offer unique properties for gas sensing applications.
• Germanium Selenide (GeSe) is a promising 2D material, but its gas sensing capabilities require enhancement.
• Formaldehyde (HCHO) and benzene (C6H6) are common indoor air pollutants with significant health implications.

Purpose of the Study:

• To investigate the gas sensing properties of pristine GeSe and Pd-decorated GeSe (Pd-GeSe) monolayers for formaldehyde (HCHO) and benzene (C6H6) detection.
• To explore the adsorption mechanisms, electronic, optical, and sensing characteristics of these 2D materials.
• To evaluate the potential of Pd-GeSe as a high-performance HCHO gas sensor.

Main Methods:

• First-principles calculations were employed to simulate gas adsorption on 2D GeSe and Pd-GeSe.
• Adsorption energies, electronic structures (band gap, electron localization function), optical properties, and charge transfer were analyzed.
• Sensitivity and recovery time were theoretically assessed to determine sensing performance.

Main Results:

• Benzene adsorption on both substrates and HCHO adsorption on pristine GeSe were identified as physisorption.
• HCHO adsorption on Pd-GeSe exhibited strong chemical adsorption with a high adsorption energy (-1.21 eV).
• Pd-GeSe showed significantly enhanced electron localization and charge transfer to HCHO, a 18.8% band gap change rate, and improved optical absorption.

Conclusions:

• The Pd-GeSe monolayer demonstrates superior sensing capabilities for HCHO compared to pristine GeSe and benzene.
• The enhanced chemical adsorption and electronic property changes indicate Pd-GeSe is a promising candidate for HCHO gas sensing.
• The study highlights the potential of 2D Pd-GeSe for developing advanced gas sensor technologies.