In situ construction of heterojunctions between Co3O4 nanonets and Fe2O3 nanospheres for efficient triethylamine detection

Abstract

Semiconductor metal oxide (MOS) sensors are extensively utilized for toxic gas detection but are often constrained by high operating temperatures, prolonged detection times, and safety risks in flammable environments. Herein, a MOF-derived Fe₂O₃/Co₃O₄ composite with a high specific surface area and abundant oxygen vacancies was synthesized via one-step annealing, achieving in situ p-n heterojunction formation. This innovative structure enabled rapid TEA detection at a low temperature of 110 °C, with a high response of 36.5–50 ppm TEA, which is 4.17 times higher than that of pure Co₃O₄. The heterojunction facilitated efficient charge separation and transport, while oxygen vacancies and the porous structure improved adsorption kinetics. Theoretical calculations further confirm the strong adsorption energy of the Fe₂O₃/Co₃O₄ toward TEA, enabling ultra-fast response and recovery times of 21 s and 33 s, respectively. Compared to the conventional MOS sensors that require high working temperatures, Fe₂O₃/Co₃O₄ sensors exhibit a lower temperature of 110 °C, resulting in reduced power consumption and improved potential for microelectronic integration. This work provides a novel, efficient approach for TEA detection, with potential applications in industrial safety and food quality monitoring.