Flexible and low power CO gas sensor with Au-functionalized 2D WS2 nanoflakes

A flexible and selective CO gas sensor was fabricated from Au-functionalized two-dimensional (2D) WS2 nanoflakes on polyamide substrate. Au-functionalized 2D WS2 nanoflakes gas sensors fabricated on polyamide can be operated under self-heating mode (1-5 V) with good selectivity to CO gas. Gas sensors fabricated on polyamide not only showed flexibility, but also demonstrated good stability and repeatability. In particular, even after 1000 times tilting, the optimized gas sensor could detect low concentrations of CO gas. The underlying sensing mechanism is discussed in detail. The results indicated the feasibility of realization of low-energy consumption and flexible gas sensors using Au-functionalization on 2D WS2 nanoflakes.