Synthesis, semiconductor characteristics and gas-sensing selectivity for cerium-doped neodymium vanadate nanorods

Ce-doped NdVO 4 nanorods (NRs) were synthesized via a one-step hydrothermal method by using edetate disodium (EDTA) as a chelating agent. Ce x Nd 1-x VO 4 NRs with square section are assigned to the zircon-type tetragonal structure, and the growth direction for NRs is along the (200) plane. Cerium in Ce x Nd 1-x VO 4 NRs is identified as substitutional dopant. Gas sensors based on Ce x Nd 1-x VO 4 NRs exhibit that the types of semiconductors transfer from n, to p and n -type (n- p - n ) with the amount of Ce. The surface for Ce 0.2 Nd 0.8 VO 4 NRs is with positive charge by Zeta potentials measurement, confirming that it corresponds to p -type semiconductor. XPS data demonstrates that the quantity for Nd 0 and V 4+ as active sites on the surface for Ce 0.2 Nd 0.8 VO 4 NRs increases by Ce doping, leading to increase in the quantity of adsorbed oxygen (O 2− ads ). According to the big dipole moment of acetone, Ce 0.2 Nd 0.8 VO 4 NRs as p -type semiconductor with high O 2− ads content interacts readily with acetone at Nd 0 and V 4+ sites during redox reaction. A gas sensor based on Ce 0.2 Nd 0.8 VO 4 NRs towards acetone gas shows distinct selectivity and a wide detecting linear range to acetone from 10 to 1000 ppm (R 2  = 0.98) at low operating temperature (108 °C).