a new article published by Materia Nova in the journal Chemosensors

Materia Nova/UMons (Driss Lahem) has published an article in the journal Chemosensors, in collaboration with the University of Dammam (Saudi Arabia), entitled: “Defect-Driven Selectivity Inversion in ZnO Gas Sensors via Y³⁺ and Dy³⁺ Doping for Enhanced VOC Detection with a Suppressed NO₂ Response”

Abstract

In this work, we demonstrate a defect-mediated strategy to fundamentally reprogram the selectivity of ZnO gas sensors through targeted doping with two types of trivalent rare-earth ions. We incorporate yttrium (Y³⁺) and dysprosium (Dy³⁺) into the ZnO host via a high-energy ball-milling (HEBM)-assisted solid-state reaction. On the basis of structural, optical, and spectroscopic characterizations, we demonstrate a significant increase in the oxygen vacancy density and a reduction in the band gap energy. The gas sensing tests revealed a remarkable inversion of selectivity: while doping suppressed the NO₂ response by 86% to 94%, it increased the sensitivity to VOCs. Dy doping produced a selective sensor for ethanol (S = 9.61, 5.62 × selectivity over NO₂), and Y doping produced a selective sensor for acetone (S = 8.27, 2 × selectivity over NO₂). This dopant-specific defect engineering provides a direct pathway to adapt ZnO sensors to the selective detection of VOCs in environmental monitoring.

Would you like to find out more? 👉👉 : https://www.mdpi.com/1424-8220/26/15/4675

Not a scientist? Here’s a brief overview of what this article is about.

Smarter sensors for detecting pollution

Researchers from Materia Nova/UMONS and the University of Dammam (Saudi Arabia) have improved resistive sensors based on zinc oxide (ZnO), a material used to detect gases in the air.

By adding very small quantities of two chemical elements, yttrium (Y) and dysprosium (Dy), they have created tiny ‘holes’ in the material’s structure, where oxygen atoms are missing. These holes alter the way the sensor reacts to gases: it becomes less sensitive to nitrogen dioxide (NO₂), but much more sensitive to certain volatile organic compounds (VOCs).

Better still, the chosen element allows the sensor to target a specific gas:

• with dysprosium, the sensor detects ethanol very effectively;
• with yttrium, it becomes highly sensitive to acetone.

By varying these additions, the sensor can therefore be ‘programmed’ to detect a specific pollutant – a promising approach for monitoring air quality in a more targeted manner.