A miniature room temperature formaldehyde sensor with high sensitivity and selectivity using CdSO4 modified ZnO nanoparticles

A light activated miniature formaldehyde sensor working at room temperature is fabricated by CdSO4 modified ZnO nanoparticles. The CdSO4 is deposited on the surface of the ZnO nanoparticles as a separated phase rather than doping into the lattice of ZnO. The Cd2+ and SO42- on the surface play a synergic effect for the high sensitivity to formaldehyde. The sensor shows high sensitivity to formaldehyde, with detection limit lower than 1 ppm while shows no response to ethanol and very weak response to acetone. With engineering efforts, a highly compact prototype formaldehyde sensor is obtained, which is very convenient for portable formaldehyde specific detection.National Natural Science Foundation of China [U1201241, 11375020, 51431001, 21321001]; Sharp Laboratory of China CO., LTD.SCI(E)EIARTICLEzhengjie@pku.edu.cn; xgli@pku.edu.cn9275098-75104