Enhanced Acetone Sensing Properties of Pt@Al-doped ZnO Core-Shell Nanoparticles

Core-shell Pt@Al-doped ZnO nanoparticles were synthesized and assembled into sensor as sensitive materials, Pt@Al-doped ZnO nanoparticles with 4 mol% Al dosage in ZnO shell layers present excellent sensitivity towards acetone. The response values of the Pt@Al-ZnO-4 % based sensor to 1 and 100 ppm acetone is as high as 9.26 and 128, and the detect limit towards acetone is as low as 20 ppb. Besides, the Pt@Al-ZnO-4 % based sensor demonstrates high selectivity and stability when exposed to acetone at relatively low concentration range. Appropriate amount of Al doping not only induces crystallinity deterioration of ZnO shells which creates more adsorption site, and also leads to a high proportion of oxygen adsorbed on the surface of ZnO shells. The synergistic effect between metal-ZnO hetero-interfaces and Al doping greatly improves the acetone sensing properties of Al doped Pt@ZnO based sensor.