Synthesis of Delafossite Materials Towards Gas Sensing Applications

Delafossite oxides (CuMO₂) are emerging as versatile materials due to their thermal stability, p-type semiconductivity, and adjustable optical features, making them useful for transparent electronics, catalysis, and sensing. This study reports the synthesis of Cu–Al–MgO₂ via a sol–gel combustion method, producing porous nanostructures with uniform elemental distribution. Structural analyses confirmed rhombohedral crystallinity and nanoscale grain size, while microscopy revealed extensive porosity favorable for adsorption. Gas sensing evaluations showed strong p-type response, rapid recovery, and stability at moderate temperatures. Magnesium incorporation enhanced oxygen vacancy formation, charge carrier mobility, and adsorption kinetics, significantly boosting sensing efficiency compared with single-cation delafossites.