Surface Modulation of Co3O4 Yolk-Shell Spheres with Tungsten Doping for Superior Acetone Sensitivity

This study introduces a promising technique to enhancethe sensitivityof p-type semiconductors in gas-sensing applications. By utilizinga glycerate-templated synthesis approach, a unique hierarchical W-dopedCo(3)O(4) yolk-shell sphere (YSS)-based sensorwas developed, exhibiting exceptional sensitivity toward acetone gas.The synthesized YSSs feature a yolk-shell structure with adiameter of approximately 500 nm and a large surface area of 117.46m(2)/g, which allows for efficient gas interaction and highsensitivity toward acetone gas. Furthermore, the incorporation oftungsten (W), a non-noble metal, as a dopant significantly enhancesthe surface activity of Co3O4, leading to aremarkably high response of 16.5 toward 5 ppm acetone, which is substantiallyhigher than that of the pure Co3O4 YSS (2.9).The W-doped Co3O4 YSS also exhibits excellentselectivity to other interfering gases and the ability to detect ultralowconcentrations of acetone as low as 10 ppb. The proposed non-noblemetal doping strategy presents a practical solution for enhancingthe sensitivity and selectivity of p-type semiconductor-based gassensors. This approach holds great potential for practical gas-sensingapplications due to their affordability and abundance, making thema cost-effective and versatile alternative to noble metal-catalyzedsensors.