Facile synthesis of Co3O4 nanochains and their improved TEA sensing performance by decorating with Au nanoparticles

A novel chain-like nanostructure of Co3O4 was successfully prepared via a facile and reliable oxalate sacrificial template route, in which coralloid cobalt oxalate (CoC2O4 center dot 2H(2)O) precursor was first obtained through a room-temperature precipitation method and then used as sacrificial template to prepare Co3O4 by annealing at 500 degrees C. Au nanoparticles-decorated Co3O4 nanochains were also prepared by soaking the CoC2O4 precursor in Au+ solution before the annealing process. The prepared samples were characterized by XRD, FESEM, TEM, and N-2 adsorption-desorption. Results indicated that the pure and Au-decorated Co3O4 nanochains were constructed by several end-to-end connected nanoparticles, and their specific surface areas were 28.42 m(2)/g and 37.39 m(2)/g, respectively. The gas sensing properties of the prepared samples were tested and compared. It was found that after being functionalized with Au nanoparticles, the Co3O4 nanochains showed an improved TEA sensing performance, such as lower optimal working temperature, higher response, and faster response and recover speed. In addition, the Au/Co3O4 sensor can also give a good linearity in the TEA concentration range from 10 to 200 ppm and considerable stability within 7 weeks, suggesting its potential application for quantitative detection of TEA. The improved gas sensing mechanism of the Au/Co3O4 nanochain was discussed. (C) 2018 Elsevier B.V. All rights reserved.