Silicon-induced oriented ZnS nanobelts for hydrogen sensitivity.

Oriented ZnS nanobelts were grown on an Si substrate using hydrogen-assisted thermal evaporation under moist gas conditions. It was found that these ZnS nanobelts had a single crystal hexagonal wurtzite structure growing along the [0001] direction. They had a rectangular cross section with lengths of up to tens of micrometres, a typical width of 50-150 nm, and a thickness of ∼40 nm. A silicon-induced vapour-liquid-solid process was proposed for the formation of the ZnS nanobelts and their assembly. These oriented nanobelts have much faster response time to hydrogen gas than that of pure ZnO and Pd-sensitized ZnO, showing excellent hydrogen sensing properties.