AUTHOR=Lontio Fomekong Roussin , Saruhan Bilge 

TITLE=Synthesis of Co3+ Doped TiO2 by Co-precipitation Route and Its Gas Sensing Properties

JOURNAL=Frontiers in Materials

VOLUME=6

YEAR=2019

URL=https://www.frontiersin.org/journals/materials/articles/10.3389/fmats.2019.00252

DOI=10.3389/fmats.2019.00252

ISSN=2296-8016

ABSTRACT=<p>Undoped and Co-doped TiO<sub>2</sub> nanoparticles were synthesized by a facile co-precipitation method and calcined at 700°C. The phase identification carried out by XRD measurements and Raman spectroscopy analysis of calcined powders reveals the formation of mainly anatase phase for undoped TiO<sub>2</sub>, and 0.5 mol.% Co-doped TiO<sub>2</sub> whereas rutile phase for 1 mol.% Co-doped TiO<sub>2</sub>. The sensors prepared with these powders deposited on interdigital (IDE) sensor platforms were tested toward NO<sub>2</sub> and H<sub>2</sub> sensing properties at 600°C. As the undoped and 0.5% Co-doped TiO<sub>2</sub> reveal n-type behavior, 1% Co-doped TiO<sub>2</sub> shows p-type semi-conductive behavior. One percentage Co-doped TiO<sub>2</sub> exhibits good sensing performance toward NO<sub>2</sub> while the undoped TiO<sub>2</sub> powder yields the best sensor performance toward H<sub>2</sub> at 600°C. This indicates that the crystal structure of TiO<sub>2</sub> sensing material must be adjusted depending on the nature of target gas. The results indicate that the main factor influencing high temperature gas sensor performance of nanoparticulate TiO<sub>2</sub> is either the alteration of its electronic structure or the type of polymorphs.</p>