In Situ Growth of Dense In2O3 Nanoparticles on Biomimetic Leaf-Shaped CdS Nanostructures for Ppb-Level Gas-Sensing Detection

A leaf-shaped CdS nanostructure modified with dense In2O3 nanoparticles (NPs) was reported to develop a high sensitive gas sensor. In2O3 NPs/CdS nanostructures were prepared by in situ growing In(2)O(3)NPs on CdS nanostructures. Compared with pure CdS, the modification of In2O3 NPs on the leaf-shaped CdS nanostructure can remarkably improve the gas-sensing properties even though towards ppb-level analytes. In gas-sensing measurements, ethanol and butanol were employed as the target gases. The gas sensor based on In2O3 NPs/CdS nanostructures was found to show high gas response and short response/recovery time. The detection limits towards ethanol and butanol can be lower than 5 ppb. As for the mechanism for such a good ppb-level gas-sensing property, the modification of dense nanoparticles and the special leaf-shaped structure which is advantageous for gas diffusion through the gas-sensing layer are demonstrated. The fascinating gas-sensing results enable the In2O3 NPs/CdS nanostructures-based gas sensor to be a potential candidate for detecting gases with trace concentrations.