Highly dispersed Ni-decorated porous hollow carbon nanofibers: fabrication, characterization, and NOx gas sensors at room temperature

Nanostructure arrays of porous hollow carbon nanofibers (HCFs) with highly dispersed functionalized Ni nanoparticles (Ni-NPs) are directly synthesized by the anodic aluminium oxide (AAO) template. HCFs with Ni-NPs are obtained after thermal decomposition of a mixture of glucose and nickel acetate inside the cylindrical nanochannels of the AAO template followed by removal of the AAO template. In the synthesis, Ni(II) ions could act as catalyst for the graphitization of amorphous carbon, and simultaneously be reduced to functionalized metal Ni-NPs. SEM, TEM, XRD, nitrogen adsorption-desorption and Raman spectroscopy reveal that the HCFs-Ni-NPs, with porous nanostructure and an average diameter of similar to 60 nm, are successfully obtained, and Ni-NPs are uniformly distributed and highly dispersed on HCFs. The HCFs-Ni-NPs have the good adsorption property of carbon materials, and the functional Ni-NPs show performance for NOx gas sensor. It is demonstrated that the HCF-Ni-NP films detect NOx gas molecules with fast response time and good sensitivity in air at room temperature owing to the structural property of HCFs and highly dispersed functional Ni-NPs. This method is promising due to its inexpensive starting materials, no pollution, direct fabrication, highly dispersed functional nanoparticles and good gas-sensing properties.