Ag-doped capsule-like tungsten oxide with controllable band structure and oxygen vacancy for highly efficient triethylamine sensing

The detection and portable monitoring of organic amine is necessary for hazardous substance warning, life, and health. Herein, capsule-like tungsten oxide nanoparticles (NPs) were prepared to detect triethylamine, and the gas-sensing property is further enhanced by adjusting oxygen vacancy and band structure by doping tungsten oxide with Ag NPs. As-prepared nanomaterial consists of well-dispersed nanoparticles with capsule-like shapes. More chemically adsorbed oxygen and oxygen vacancy are formed in Ag-doped tungsten oxide, and bandgap decreases compared with pristine tungsten oxide. The gas-sensing tests show that the optimal Ag-doped tungsten oxide (Ag/WO3) NPs-based sensor exhibits more than six times the response higher than that of pristine tungsten oxide toward 50 ppm triethylamine (TEA) at an optimal temperature of 220 °C, with a detection limit as low as 248 ppb. Notably, fast response and recovery time and anti-interference properties are remarkable, and the two-week stability is also satisfactory, which are superior to reported related materials. For real-time TEA detection, as-prepared Ag/WO3 is proved to be efficient sensing material for portable monitoring applications.