Structural, optical, and gas sensing characteristics of synthesized environmentally friendly ZnO-ZnAl2O4 nanocomposites

Abstract

In this study, we synthesized ZnO-ZnAl2O4 composites from orange peel extract by using an environmentally friendly approach. ZnO-ZnAl2O4 composites with different Al content, namely 30, 40, 50, 60, and 70 at%, were successfully synthesized, and they were characterized in detail using advanced techniques to study their structures, phases, morphologies, and electrical and optical properties. Gas sensing measurements for H2S gas showed that the sensor with 70 at% Al had the best response at 350 degrees C along with long-term stability. We attribute this high response to the high specific surface area (48.8 m2 & sdot;g-1), the formation of ZnO-ZnO homojunctions and ZnOZnAl2O4 heterojunctions, and the high intrinsic sensing properties of the ZnO phase. This study is expected to contribute to the development of green approaches for the synthesis of environmentally friendly gas sensing materials.