Enhanced Cl2 sensing performance by decorating discrete Au nanoparticles on octahedral CdIn2O4 crystals

Abstract

High response to low-concentration Cl₂ gas was achieved by a sensor based on octahedral crystals of CdIn₂O₄ decorated by Au nanoparticles (Au NPs). CdIn₂O₄ crystals were synthesized in a one-step hydrothermal reaction and Au NPs were functionalized onto CdIn₂O₄ also in a hydrothermal reaction. Systematic investigations revealed that the Au NPs-decorated CdIn₂O₄ samples possessed a superior sensing capability, compared with bare CdIn₂O₄ crystals. The optimal Au NPs loading (2 wt%) resulted in 8.3-fold enhancement in gas response to 1 ppm Cl₂ at the working temperature, 190 °C, compared to bare CdIn₂O₄. The Au NPs on the surface enhanced the sensor response due to the catalytic activity of Au NPs and the strong electronic interaction between Au NPs and CdIn₂O₄ support. This work provides a promising approach for fabricating such a hybrid structure with excellent gas sensing capabilities.