Sm3+ doped Bi2MoO6 microspheres with enhanced ethylene glycol sensing performance

Abstract

Bi2MoO6 (BMO) micro nanocrystals doped with rare earth ion samarium (Sm) were synthesized by hydrothermal method combined with high-temperature calcination method. SEM analysis showed that Sm element was uniformly distributed into BMO microspheres. By comparing the gas sensitivity test results of BMO and different concentrations of Sm-doped BMO, it is found that 4 mol% Sm-BMO has a lower optimal operating temperature. Eight VOC gases were tested and it was found that the sensor has a good selectivity for ethylene glycol, and at 240 °C, The glycol response values were 6.1 and 60.1 for 5 ppm and 100 ppm, respectively. The adsorption and desorption times are 20 s and 78 s. The reason for the improvement of gas sensitivity may be that the successful incorporation of rare earth ion Sm into the lattice of BMO increases the content of vacancy oxygen (Ov), makes the sample coarser, changes its band gap energy, induces the effective separation of electrons and holes, and improves the gas sensitivity of Sm-BMO. This work provides a research idea for improving gas sensitive performance of multi-component semiconductors doped with the optimal concentration of rare earth elements.