TiO2 hierarchical nano blooming-flower decorated by Pt for formaldehyde detection

To achieve an ultra-low concentration formaldehyde detection at low temperature, a platinum (Pt) assisted TiO2 hierarchical nano blooming-flower sphere material is synthesized through hydrothermal method. SEM and transmission electron microscope characterizations show that the diameter of the nano sphere was around 2 μm with dissilient rods of 60 nm in diameter and 1 μm in length on the surface. The response (Ra/Rg) achieved form this nanomaterial to HCHO is 1.08 (100 ppb) and 5.82 (5 ppm) at 130 °C without an involvement of any light source or solution. The relationship curve between the responses and concentrations shows regular exponential trend. The verification of sensor stability done by a 3 month reliability test shows no response-degradation. The optimal response and stability is attributed to the massive dissilient rods on the surface of TiO2 spheres and the assistance of Pt as a catalyzer disperses to intensify the formation of depletion area on the surface of TiO2. This study provide an attractive and cost effective solution for the detection of HCHO in air at a relatively low temperature.