Printable cobalt–nickel vanadate-based ozone gas sensors, operating at low temperatures

Abstract Ozone (O 3 ) is a hazardous environmental gas that is damaging to human health. Thus, there is an urgent demand for low-cost O 3 gas sensors with a low energy consumption . Herein, cobalt–nickel vanadate [(Co 0.75 Ni 0.25 ) 3 V 2 O 8 ] nanoparticles were synthesized by a simple and cost-effective solvothermal process for the first time. The structural, morphological, electrical and optical properties of (Co 0.75 Ni 0.25 ) 3 V 2 O 8 nanoparticles were determined using various characterization techniques. In addition, a printable (Co 0.75 Ni 0.25 ) 3 V 2 O 8 -based gas sensor was fabricated by a direct ink writing technique and tested on O 3 at a low operating temperature. The sensor successfully detected O 3 concentrations far below 100 parts per billion by volume (ppbv), with the low detection limit decreasing from 57 to 42 ppbv with an increase in the operating temperature from 25 °C to 80 °C. The highest sensor signal was 5 for 650 ppbv O 3 at a low temperature of 80 °C. Based on this enhanced gas-sensing performance at a low operating temperature as well as on the low-cost fabrication technology, (Co 0.75 Ni 0.25 ) 3 V 2 O 8 is a promising gas-sensing element for environmental O 3 monitoring applications.