Facile approach to prepare hierarchical Au-loaded In2O3 porous nanocubes and their enhanced sensing performance towards formaldehyde

Controlling the morphology of materials and surface modification with noble metal are considered as effective strategies to improve gas-sensing properties of sensors based on metal oxide. In this work, hierarchical Au-loaded In2O3 porous nanocubes have been successfully synthesized by a two-step approach including a facile hydrothermal reaction and subsequent in situ reducing process. Various methods were employed to characterize the structure and morphology of as-obtained hierarchical Au-loaded In2O3 porous nanocubes. The results reveal that the side length of In2O3 nanocubes is about 150-200 nm and the Au nanoparticles attached on it is about 15 nm. The specific surface area of hierarchical Au-loaded In2O3 porous nanocubes is 38.1 m(2)/g, and main pore size is distributed in of 8-9 nm. In addition, the hierarchical Au-loaded In2O3 porous nanocubes based sensor possesses highly sensing performance for formaldehyde detection. The response value to 100 ppm formaldehyde is about 37 at an operating temperature of 240 degrees C, which is doubled than the pure one and reduced the operating temperature. The response and recovery time are 3 and 8 s, respectively. It is expected that hierarchical Au-loaded In2O3 porous nanocubes with excellent gas-sensing performance is a promising functional material to actual application in formaldehyde detection. (C) 2016 Elsevier B.V. All rights reserved.