Enhanced ppb-level formaldehyde sensing performance over Pt deposited SnO2 nanospheres

Formaldehyde is one of the most serious threats to human health in modern interior decoration. Thereby, online detection of indoor formaldehyde concentration has become an urgent problem. In this work, the Pt deposited porous SnO2 nanospheres were synthesized as the formaldehyde sensing materials, which were prepared by hydrothermal and chemical reduction methods. The diameter of as-synthesized Pt-SnO2 were centered in the range of 30–50 nm, with the dominant pore size of ~10 nm and the specific surface area of 89.79 m2 g−1, which provided a raft of passages and active sites for gas molecules to diffuse and interact mutually. Moreover, the experimental results demonstrated that the 1 wt.% Pt-SnO2 exhibited higher response (16.03), high-speed response time (9 s) and outstanding selectivity with exposure to low-concentration formaldehyde compared with original SnO2. The porous structures and catalytic effect of Pt nanoparticles were jointly responsible for the enhancement of SnO2 on sensing performance towards formaldehyde.