MoS2-Templated Porous Hollow MoO3 Microspheres for Highly Selective Ammonia Sensing via a Lewis Acid-Base Interaction

The development of a high-performance sensing material for the detection of ammonia gas is of significant importance due to its wide industrial presence and potential hazard risks. In this article, we report the synthesis of porous and hollow MoO3 (p-h-MoO3) microspheres via the oxidation of MoS2 microsphere templates, which are obtained via self-assembly of MoS2 nanosheets under hydrothermal conditions. The composition and morphology of the p-h-MoO3 microspheres are systematically characterized via microscopic and spectroscopic techniques, and our sensing tests reveals that p-h-MoO3 possesses ultrahigh responsiveness to ammonia gas, which can be further optimized via the selection of a suitable oxidation temperature and time. Additionally, the p-h-MoO3 shows minimal responses to other gaseous molecules, thereby demonstrating significant selectivity toward ammonia. The sensing mechanism of p-h-MoO3 toward ammonia is further investigated to identify the origin of its ultrahigh sensitivity and selectivity via X-ray photoelectron spectroscopy and diffuse reflectance Fourier transform infrared spectroscopy.

Automated summary

This article reports the synthesis of porous and hollow MoO3 microspheres for the detection of ammonia gas. The study found that p-h-MoO3 exhibits ultrahigh responsiveness to ammonia with significant selectivity. The composition and morphology of p-h-MoO3 were characterized using microscopic and spectroscopic techniques, and the sensing mechanism was investigated using X-ray photoelectron spectroscopy and diffuse reflectance Fourier transform infrared spectroscopy.