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

Abstract

This study introduces a promising technique to enhance the sensitivity of p-type semiconductors in gas-sensing applications. By utilizing a glycerate-templated synthesis approach, a unique hierarchical W-doped Co 3 O 4 yolk−shell sphere (YSS)based sensor was developed, exhibiting exceptional sensitivity toward acetone gas. The synthesized YSSs feature a yolk−shell structure with a diameter of approximately 500 nm and a large surface area of 117.46 m 2 /g, which allows for efficient gas interaction and high sensitivity toward acetone gas. Furthermore, the incorporation of tungsten (W), a non-noble metal, as a dopant significantly enhances the surface activity of Co 3 O 4 , leading to a remarkably high response of 16.5 toward 5 ppm acetone, which is substantially higher than that of the pure Co 3 O 4 YSS (2.9). The W-doped Co 3 O 4 YSS also exhibits excellent selectivity to other interfering gases and the ability to detect ultralow concentrations of acetone as low as 10 ppb. The proposed non-noble metal doping strategy presents a practical solution for enhancing the sensitivity and selectivity of p-type semiconductor-based gas sensors. This approach holds great potential for practical gas-sensing applications due to their affordability and abundance, making them a cost-effective and versatile alternative to noble metal-catalyzed sensors.

Mixed Potential Type Acetone Sensor with Ultralow Detection Limit for Diabetic Ketosis Breath Analysis

“…Surprisingly, the sensor still exhibits a clear response signal of −7.9 mV to 10 ppb acetone; such a low detection limit is the best performance of the current mixed potential acetone sensors and is not often seen even in other types of acetone sensors. Table provides a detailed comparison for the experimental detection limits of existing acetone sensors. ,,− Such an extremely low detection limit helps to move forward the detection window and provides efficient early warning in practical applications. In addition, obvious spikes are observed at high concentrations, which is due to the insufficient number of reactive sites at TPB and the gas desorption process having a greater impact on the sensing process.…”

Increasing the Catalytic Activity of Co3O4 via Boron Doping and Chemical Reduction for Enhanced Acetone Detection

“…In addition to the above mentioned strategies, other approaches have been developed to optimize the design of Co 3 O 4based materials for acetone detection. [11,12] Compared to pristine sensing materials, these Co 3 O 4 materials exhibit a higher reactivity and enhanced sensing performance. However, most of these methods have the disadvantages of high cost, increased time consumption, and low product yield.…”