A Novel Indium Oxide-Based Nanostructured Material Designed for CO2 Detection

Low-cost sensors working at low/room temperature for CO2 mapping in indoor–outdoor environments are in growing demand. Solid-state gas sensors are a suitable alternative to expensive optical sensors, but to date, materials designed for chemoresistive devices have not proven functional for CO2 detection. This work addresses this challenge both in terms of sensing materials research, with the innovative use of alkali metals as dopants in semiconductors, and in terms of deeply understanding the sensing mechanism through DRIFT spectroscopy. The result is a sensor operating at 200 °C that detects CO2 between 250–5000 ppm with a negligible effect of humidity above 17 RH%.