Synthesis of Mo₄O₁₁@MoO₃ nanobelts and their improved sensing performance to NO₂ gas

In the present work, Mo₄O₁₁ @MoO₃ nanobelts are successfully prepared by a two-step hydrothermal method. The nanobelts are about several micrometers in length and 200-300 nm in width with Mo₄O₁₁ nanoparticle on surface. The introduction of nanoparticles act as the adsorption sites which facilitate the adsorption of O₂ and NO₂ gas molecules, because of the point defects such as Mo⁵⁺ ions and oxygen vacancies inducing to increase the concentration of carriers, which synthetically contribute the sensing performance enhancement. The Mo₄O₁₁@MoO₃ nanobelts show excellent sensing performance with 6 times enhancement with the decreased working temperature comparing with the pure α-MoO₃ nanobelts. This study indicate that this kind of sensor show a promising application in NO₂ detection.