Synergistic effect between UV light and PANI/Co3O4 content on TiO2 composite nanoparticles for room-temperature acetone sensing.

Ternary hybrid composites are less explored for gas sensing purposes due to their complexity of structures. However, their complexity brings about a greater potential for resistance changes. In this study, we have synthesized a new ternary hybrid composite composed of polyaniline (PANI)-loaded Co 3 O 4 -TiO 2 composite nanoparticles (NPs) for acetone sensing at 25 ℃. For this purpose, PANI and Co 3 O 4 were added into TiO 2 NPs using sol-gel method. The gas sensing characteristics of PANI-TiO 2 , Co 3 O 4 -TiO 2 composite NPs and PANI-loaded Co 3 O 4 -TiO 2 composite NPs sensors were systematically investigated with and without UV illumination (at 25 °C). Based on the sensing results, the ternary 0.01 wt% PANI-loaded 0.85TiO 2 − 0.15 Co 3 O 4 composite NPs revealed the highest response to acetone under UV illumination at 25 ℃. The enhanced performance of optimized gas sensor was due to formation of p-n heterojunctions, promising effects of PANI, and UV light effect. The results obtained herein, highlighted the possibility of making a highly reliable acetone sensor working at 25 ℃ using this compounds or related compounds. • Gas sensing properties of PANI-Co 3 O 4 loaded TiO 2 nanoparticles were examined. • Heterojunctions and adsorbed oxygen species contributed to the sensing enhancement. • Higher adsorption energy between acetone and TiO 2 improved the selectivity. [ABSTRACT FROM AUTHOR]