Preparation of Hollow Spherical MgFe₂O₄ Material and Its Application in Acetone Sensing

Employing a hydrothermal method and a calcination process, we synthesized an oxygen vacancy‐laden, open‐porous, hollow spherical structure of MgFe 2 O 4 , demonstrating exceptional acetone‐specific responsiveness. The experimental findings reveal that at 250 °C, MgFe 2 O 4 exhibits a response value from 49.77 to 100 ppm acetone concentrations, with a detection limit as low as 0.59 ppm. The response and recovery times are recorded between 12 s and 23 s, respectively, indicating rapid response and recovery characteristics. Furthermore, MgFe 2 O 4 maintains stable responsiveness under 80% RH humidity, showcasing commendable moisture resistance. Over an extended period of 45 days, MgFe 2 O 4 maintains stability, with response fluctuations below 2.5% across 20 repeated cycles. An in‐depth analysis of the acetone selectivity and response mechanism of MgFe 2 O 4 was conducted, considering pore structure, crystal plane polarity, and dipole moment. The advancements presented in this study offer significant insights into the structural design and performance optimization of high‐performance acetone‐responsive materials.