Rational design of hierarchical hollow spherical W18O49 with abundant oxygen vacancies through Mo doping for efficient TEA gas sensing

Abstract

Triethylamine (TEA), a toxic and flammable compound, poses a significant threat to human health, particularly affecting the respiratory and hematological systems. Hence, developing a gas sensor capable of detecting TEA with high sensitivity, selectivity, and stability is of critical importance. In this work, hierarchical hollow spherical Mo-doped W₁₈O₄₉ enriched with oxygen vacancies was successfully synthesized via a simple and cost-effective one-step hydrothermal route. The experimental results indicate that the incorporation of high-valence molybdenum (Mo) into the W₁₈O₄₉ crystal lattice facilitates the creation of oxygen vacancies and modulates the electronic structure, thereby significantly enhancing the redox capability and catalytic efficacy toward TEA gas. The optimized 4 at% Mo-doped W₁₈O₄₉ sensor exhibited excellent TEA-sensing performance, including reduced operating temperature, enhanced response, exceptional long-term stability and excellent selectivity. The improved sensing capabilities are primarily attributed to the presence of highly active centers resulting from abundant oxygen vacancies and activation of the lattice oxygen. Furthermore, the underlying gas sensing mechanism of hierarchical hollow spherical Mo-doped W₁₈O₄₉ was also investigated. This innovative sensor provides a highly efficient and reliable solution for TEA detection, holding significant potential for applications in environmental monitoring and food safety assurance.