Hydrothermal synthesis and ethanol sensing properties of CeVO_4 and CeVO_4-CeO_2 powders

摘要

CeVO_4 powders with different morphologies were synthesized in basic media by surfactant-free hydrothermal process. The products were characterized by X-ray diffraction and transmission electron microscopy (TEM). From the experimental results, it has been revealed that there is an optimal pH range (pH < = 12.0) for the formation of pure CeVO_4 and the pH plays a key role in the formation of the products of different morphologies and sizes. Increasing pH from 9 to 10 causes the morphology transformation: irregular nanoparticles - > nanorods. High pH (12.0H<14.0) resulted in the formation of CeVO_4-CeO_2 compounds. Gas sensing behavior of CeVO_4 and CeVO_4-CeO_2 based materials to ethanol were firstly studied. The sensors based on these materials show different response to ethanol, wherein the response is the best when using CeVO_4-CeO_2 compounds as material.