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.