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

Abstract A novel chain-like nanostructure of Co 3 O 4 was successfully prepared via a facile and reliable oxalate sacrificial template route, in which coralloid cobalt oxalate (CoC 2 O 4 ·2H 2 O) precursor was first obtained through a room-temperature precipitation method and then used as sacrificial template to prepare Co 3 O 4 by annealing at 500 °C. Au nanoparticles-decorated Co 3 O 4 nanochains were also prepared by soaking the CoC 2 O 4 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 Co 3 O 4 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 Co 3 O 4 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/Co 3 O 4 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/Co 3 O 4 nanochain was discussed.