Submicrochains composed of massage ball-like WO3@CuWO4 composites for high-efficiency CO gas sensing applications at room temperature

Abstract

Submicrochains composed of massage ball-like WO₃@CuWO₄ composites with nano-sized WO₃ protrusions on submicro-sized CuWO₄ particles were prepared via a simple Cu²⁺ intercalation method. WO₃ grains (8 to 15 nm) modified on the surface of mesoporous single crystal CuWO₄ particles with 100 to 300 nm size resulted in the formation of a WO₃–CuWO₄ heterojunction with a Cu : W atomic ratio up to 3 : 10. The disperse density of the WO₃ nanoparticles (NPs) depended on the excess quantity of raw material H₂WO₄. The gas sensing results show that the massage ball-like WO₃@CuWO₄ sensor possessed a 54.2% higher response for 1000 ppm CO, and a low 5 ppm CO detection limit at room temperature (RT); compared with WO₃@CuWO₄ sensors, mesoporous the CuWO₄ submicrochain sensor had the fastest response time of the whole CO concentration range and the response time was only 1.0 s for 1000 ppm CO gas and 3.7 s for 10 ppm CO gas at RT.