Unique polyhedron CeO2 nanostructures for superior formaldehyde gas-sensing performances

Highly exposed surface area CeO2 polyhedral nanostructures were successfully prepared via a two-step hydrothermal route for gas-sensing applications. The surface chemistry and formation of polyhedral nanostructures was attributed to the interaction between polyvinylpyrrolidone and ammonium bicarbonate surfactants with parent ceria. The synthesized polyhedron CeO2 structures were characterized using XRD, XPS, BET, SEM, EDS and TEM, respectively. The polyhedrons exhibited a high specific surface area 98.76 m2/g. For gas-sensing applications, the CeO2 polyhedrons were exposed to different gases at various temperatures, from a low to high concentration range (1–150 ppm). At an optimal temperature 220 °C, superior gas-sensing response towards formaldehyde was observed than other target gases. The enhanced sensor response was attributed to multifaceted polyhedral nanostructures. The polyhedral structure based sensors have great potential in industrial sensing applications.