Nickel nanoparticle-decorated reduced graphene oxide/WO <sub>3</sub> nanocomposite – a promising candidate for gas sensing
Ilka Simon, A. A. Savitsky, Rolf Mülhaupt, Vladimir Pankov, Christoph Janiak
Abstract
We report for the first time the combination of WO 3 sensing elements with a non-noble metal–carbon composite, namely a nickel metal nanoparticle–carbon composite (Ni@rGO). Previous work with WO 3 had used either NiO (as part of the WO 3 lattice), solely carbon, Pd-surface decorated WO 3 (Pd@WO 3 ), or Pd or Pt@carbon@WO 3 . We demonstrate the gas response for pure WO 3 , rGO/WO 3 and Ni@rGO/WO 3 sensing elements towards NO 2 and acetone in air as well as towards CO in N 2 . The addition of 0.35 wt % Ni@rGO composite to WO 3 enables the increase of the sensory response by more than 1.6 times for NO 2 vapors. The gas response towards acetone using 0.35 wt % Ni@rGO/WO 3 composite was 1.5 times greater for 3500 ppm than for 35,000 ppm acetone. For 0.35 wt % Ni@rGO/WO 3 composite and CO gas, a response time ( T res ) of 7 min and a recovery time ( T rec ) of 2 min was determined.