A highly sensitive and fast-responding ethanol sensor based on CdIn ₂O₄ nanocrystals synthesized by a nonaqueous sol-gel route

CdIn₂O₄ nanoparticles with crystallite sizes of about 10 nm were obtained by a nonaqueous sol-gel route involving the reaction of cadmium acetate and indium isopropoxide in benzyl alcohol. Without the use of any additional stabilizing agents, the crystal growth is restricted by the solvent and/or by the organic reaction products. The as-fabricated sensor showed high response, fast response, and recovery times toward ethanol gas. The performance of a home-built CdIn₂O₄ nanocrystal sensor was even better than the competing SnO₂ and In₂O₃ sensors, making this material not only interesting for sensor devices, but also for a number of related electrochemical applications.