Recent advances in p-type delafossite ABO2 based chemiresistive gas sensors

Exploring novel ternary oxide sensing materials with distinctive/ tuneablesurface properties, beyond the conventional binary oxides (n-type SnO 2 , ZnO, WO 3 , etc.), has attracted increasing attention for constructing large sensor arrays for advanced E-nose with exceptional recognition capability. Delafossite ABO 2 (A is monovalent cation Ag or Cu, B is trivalent cations Al, Cr or Ga, etc.) oxides, featured by species diversity (more than 20 species with distinctive catalytic properties) and p-type conductivity, have emerged as exciting contenders for the next generation of IoT or E-nose sensors. Beginning with the fundamental properties of delafossite oxides, this review summarizes the progress of delafossite based chemiresistive gas sensors, emphasizes the crucial role of defects engineering, single atom (SA) anchoring and pulsed temperature modulation (PTM) in enhancing sensitivity towards the specific target gases. Finally, their promising applications in diverse areas have been anticipated.