Self-assembled In2O3 truncated octahedron string and its sensing properties for formaldehyde

A continuous two-step route consisting of ammonolysis and re-oxidation processes was developed for in-situ growth of In2O3 truncated octahedron strings. The truncated octahedron strings were self-assembled by In2O3 crystals, and several tens of micrometers along their longitudinal axes. The gas sensing properties of the sensors based on as-synthesized In2O3 were investigated, and the sensor exhibited a significant response for formaldehyde at a concentration lower to 5 ppm.