Eu3+-doped MoO3 one-dimensional ice-lolly-like nanorods: Achieving red down-conversion luminescence and significantly enhancing triethylamine gas-sensing performance

Abstract

A novel MoO3:x%Eu3+ one-dimensional (1D) ice-lolly-like nanorods with bifunctionality of luminescence and gas sensitivity are successfully prepared via electrostatic spinning and oxidative calcination. Among them, MoO3:x%Eu3+ 1D ice-lolly-like nanorods exhibit exceptional luminescence properties, with an emission peak at 616 nm when excited at a wavelength of 274 nm. The MoO3:x%Eu3+ 1D ice-lolly-like nanorods possess excellent gas-sensitizing properties to triethylamine (TEA) when they are fabricated to be gas sensors. The response value of MoO3:1%Eu3+ 1D ice-lolly-like nanorods gas sensor to 100 ppm TEA at 290 °C is 127.9, which is 11.5 times higher than that of the pure MoO3 (11.1) gas sensor. Furthermore, the MoO3:1%Eu3+ 1D ice-lolly-like nanorods gas sensor exhibits an ultra-fast response/recovery time (1 s/14 s). In addition, doped Eu3+ at the MoO3 interface leads to enhanced electronic and catalytic properties, thereby leading to a significant improvement in the gas-sensing performance of MoO3. More importantly, the doping of Eu3+ can simultaneously achieve excellent red down-conversion luminescence performance and enhance the gas-sensitive properties of MoO3. This can be attributed to the fact that Eu3+ serves as both a luminescent center and a sensitizer for MoO3, achieving the effect of killing two birds with one stone. The possible mechanisms of photoluminescence and gas sensing are also proposed. This design idea introduces an innovative approach for rapidly detecting damage to the sensing coating of gas sensors, achieved by illuminating the sensing material with excitation light. This work offers insights for constructing novel bifunctional composites with luminescence and gas sensing, broadening the application of gas sensors.