Gas-solid Interfacial Charge Transfer in Volatile Organic Compound Detection by CuCrO2Nanoparticles.

Nanostructured metal oxide semiconductors have received great attention used as the chemiresistive layer of gas sensor to detect the volatile organic compound recently. Among these, p-type semiconductors have many advantages, such as temperature/humidity stability and compositional versatility; however, the study of sensing mechanism is still insufficient, which hampers their practical applications. In this work, the p-type delafossite CuCrO2nanoparticles were synthesized, characterized, and tested for gas sensing, followed by the first principles calculations to simulate the generation of chemiresistive signal. The adsorption sites and charge variations of dehydrogenation at the gas-solid interface predicted by the theoretical analysis are claimed to be crucial to the gas sensing properties, in terms of sensitivity and selectivity, which are consistent with the experimental results. It is an innovative approach to understand the chemiresistive gas sensing by evaluating the preference of charge transfer between the sensor and target gaseous molecule, which provides a new route to precisely design and develop the advanced sensing devices for the diverse applications.