The Jahn–Teller distortion-induced electronic structure regulation of Mn-doped Co3O4 for enhanced acetone detection

Abstract

The modulation of the electronic structure of metal oxides is crucial to enhance their gas-sensing performance. However, there is lacking in profound study on the effect of electronic structure regulation on sensing performance. Herein, we propose an innovative strategy of Jahn–Teller distortion-induced electronic configuration regulation of Co₃O₄ to improve acetone sensing performance. After the introduction of Mn³⁺ into Co₃O₄ (Mn-Co₃O₄), the Jahn–Teller distortion of high-spin Mn³⁺ (t_2g³e_g¹) conversed to low-spin Mn⁴⁺ (t_2g³e_g⁰), resulting in conversion of Co³⁺ (t_2g⁶e_g⁰) into Co²⁺ (t_2g⁶e_g¹). As expected, Mn-Co₃O₄ exhibits a high response value of 46.7 toward 100 ppm acetone, low limit of detection of 0.75 ppb, high selectivity, and high stability, which are overwhelmingly superior to previous Co₃O₄-based acetone sensors. The dynamics and thermodynamics analysis demonstrate that the Mn doping improves sensing reaction rate, reduces reaction barrier, and promotes the charge transfer. The theoretical calculations further prove the charge transfer from Mn to Co derived from Jahn–Teller distortion and support promoting the adsorption of acetone on Co₃O₄ by Mn dopant. Moreover, we demonstrated the substantial potential application of Mn-Co₃O₄ sensor as a monitoring gas sensor in pest resistance of Arabidopsis. This work provides a new strategy to design sensing materials from electronic configuration perspective.