Synergistic Effect of Nanocrystalline SnO2 Sensitization by Bimetallic Au and Pd Modification via Ingle Step Flame Spray Pyrolysis Technique

Convenient and scalable single step flame spray pyrolysis (FSP) synthesis of bimetal AuPd sensitized nanocrystalline SnO2 for gas sensor application is reported. The materials chemical composition, structure and morphology has been studied by XRD, XPS, HAADFSTEM, BET, ICP-MS techniques as well as thermo-programmed reduction with hydrogen (TPR-H2). Superior gas sensor response of bimetal modified SnO2 towards wide concentration range of reducing (CO, CH4, C3H8, H2S, NH3) and oxidizing (NO2) gases compared to pure and monometallic modified SnO2 is reported. The observed enhanced gas sensor performance is concluded to arise from combination of facilitated oxygen molecule spillover on gold particles and electronic effect of Fermi level control by reoxidizing Pd-PdO clusters, homogeneously distributed over SnO2 particles surface.