Boosting Ethylene Glycol Sensing Performance with Dendritic Hierarchical CuO/Co₃O₄ Heterojunction Nanowire

Abstract

Heterostructures comprising metal oxide semiconductors (MOSs) have proven to be effective techniques in the development of high-performance gas sensors. In this study, we developed a feasible hydrothermal technique for the synthesis of a hierarchical dendritic CuO/Co 3 O 4 nanowire heterostructure, which exhibits a strong affinity for ethylene glycol (EG) adsorption. The resulting gas sensor, based on a hierarchical CuO/Co 3 O 4 heterostructure, has an exceptionally high response (6.3) to 100 ppm EG at 130 °C. The enhanced sensing performance toward EG can be attributed to the formation of a unique CuO/Co 3 O 4 core–shell heterojunction structure. The mechanism behind this enhanced performance is explained by the heterojunction-depletion model, which takes into account precise band alignments. This study serves as inspiration for the design of various p–p heterojunctions in the development of high-performance gas sensors. A feasible hydrothermal technique was developed for obtaining a hierarchical dendritic CuO/Co 3 O 4 nanowire heterostructure with high EG gas sensing performance.