3D hierarchical In2O3 nanoarchitectures consisting of nanocuboids and nanosheets for chemical sensors with enhanced performances

3D hierarchical In2O3 nanoarchitectures with nest-like superstructure were produced successfully with a two-phase solvothermal approach and annealing process for the first time. Nanocuboids and nanosheets with smooth surfaces, which form the 3D nanoarchitectures, can convert to porous In2O3 configurations after annealed at 300 °C for 2 hours. The hierarchical In2O3 materials were applied to make chemical sensors together with Pd nanoparticles. It was found that the devices made with 3D nest-like In2O3 and Pd nanoparticles exhibit enhanced performances in detecting reducing gases, compared to their counterparts fabricated with pure In2O3 materials. Specifically, the sensitivity (S=Ra/Rg) and selectivity of the devices to acetone vapor of 100 ppm can be improved dramatically, after attaching Pd nanoparticles onto the surfaces of the nanoarchitectures.