A high-performance room temperature benzene gas sensor based on CoTiO3 covered TiO2 nanospheres decorated with Pd nanoparticles

A benzene sensor based on Pd doped CoTiO3/TiO2 (Pd-CTT) nanocomposite was reported in this paper. The surface morphology and structure composition of the samples were investigated by SEM, TEM, XRD and XPS. The benzene sensing performance of the sensors with different ratios of CoTiO3 and TiO2 was studied at room temperature (RT) of 25 °C. The gas sensing performance of the sensor was further improved by the construction of Pd-CTT ternary composite sensing material. The results show that the sensor has remarkable sensing performance for benzene, including excellent linear response, rapid detection speed, good repeatability and stability. The Pd-CTT sensor showed a high response (Rg/Ra = 33.46 @ 50 ppm) to benzene, with detection limit as low as 100 ppb. The excellent benzene sensing properties of Pd-CTT sensor are attributed to the formation of CoTiO3/TiO2 p-n heterojunction and catalytic action of Pd. This work highlights the unique advantage of Pd-CTT nanocomposite for benzene sensor.