Enhancement of CO gas sensing performance by Mn-doped porous ZnSnO3 microspheres

Abstract

This work reports the synthesis of Mn-doped ZnSnO₃ microspheres (Zn_1−xMn_xSnO₃) using a simple co-precipitation method with (x = 0 to 0.15) and characterized for structural, morphological, surface area, and sensing properties. X-ray diffraction (XRD) analysis revealed the face-centered cubic structure of Mn-doped ZnSnO₃ samples. Brunauer–Emmett–Teller (BET) analysis demonstrated the variation in surface area from 15.229 m² g⁻¹ to 42.999 m² g⁻¹ with x = 0 to 0.15 in Zn_1−xMn_xSnO₃. XPS indicates the change in the defect levels by Mn doping, which plays a crucial role in chemical sensors. Indeed a significant increase (≈311.37%) in CO gas sensing response was observed in the x = 0.10 sample compared to pure ZnSnO₃ with a simultaneous reduction in operating temperature from 250 to 200 °C. Moreover, remarkable enhancements in response/recovery times (≈6.6/34.1 s) were obtained in the x = 0.10 sample. The Mn-doped ZnSnO₃ could be a promising candidate for CO gas sensing devices used for maintaining air quality.