Amorphous Eu0.9Ni0.1B6 Nanoparticles for Formaldehyde Vapor Detection

Amorphous Eu0.9Ni0.1B6 nanoparticles are fabricated through a coreduction approach with the aid of phosphite ions under a liquid plasma field. This approach achieves not only better gas response/recovery time (<20 s) but also a lower detection limit (15 ppb) and higher antihumidity (relative humidity of 90%) toward formaldehyde vapor than any prior reports of formaldehyde sensing materials at 25 degrees C. This is attributed to the introduction of Ni that enriches Eu with more electrons and facilitates the easy transfer of electrons from Eu in Eu0.9Ni0.1B6 to O in formaldehyde. Meanwhile, Ni doping efficiently reduces the surface free energy of Eu0.9Ni0.1B6 and enhances its hydrophobicity.