Sensing devices of volatile organic compounds based on ZnO hollow/p-type semiconductors heterostructures

Abstract

The detection of Volatile Organic Compounds (VOCs) has been of great interest because they can be toxic, explosive, flammable or exhaled in human breath, functioning as biomarkers. Among the different ways of detecting VOCs, the use of metal oxide semiconductors is the most promising. These materials have a simple operation mechanism based on conductance change, easy production and low cost. However, these materials have some limitations, such as high operating temperature, low analyte selectivity, low sensitivity and humidity interference. In view of these limitations, this research proposal aims to study the effect of hollow structures of ZnO modified with p-type semiconductors in the detection of VOCs (eg: alcohols, ketones, aldehydes, amines, aromatic compounds) at room temperature in the presence of humidity, similar to environmental conditions and human breath. It is expected to obtain materials with excellent VOCs detecting performance at room temperature, due to the effect of hollow structures, which promotes an increase in diffusion and surface area, and in the presence of humidity, due to the effect promoted by p-n heterojunction, where p-type semiconductor material makes the material less susceptible to the negative effect of humidity. In addition, one of the major challenges of the research will be to develop new miniaturized (low cost of production) sensor devices with the aid of a 3D-printer to detect VOCs in environmental and human breathing conditions, making possible the real application. This proposal will be supported by regular research support financed by FAPESP (Process 17/01267-1). (AU)