Increasing the Surface Activity of 2D Ultrathin Co3O4 by Indium Doping for TEA Sensing

Optimizing and improving the surface activity of Co3O4 sensing materials are crucial for applications in triethylamine detection. Herein, indium-doped Co3O4 hollow microflowers (InCo HMfs), assembled from ultrathin nanosheets, were prepared via a hydrolysis reaction. Three distinct crystal facets─{1 1 0}, {1 1 1}, and {0 0 1}─were observed in 2-InCo HMfs. Results from TEM, XPS, and XAS characterization show that the increase of Co2+ content induced by indium doping promotes the formation of highly active crystal planes in Co3O4. DFT calculations revealed the reasons for the improvement in the gas sensing performance of 2-InCo HMfs and the multiple effects of In ions. Our dual strategy of doping with indium and hydrolysis markedly improved the intrinsic TEA sensing performance of Co3O4, offering a novel avenue for designing high-performance TEA sensors.