Nickel nanoparticle-decorated reduced graphene oxide/WO(3) nanocomposite – a promising candidate for gas sensing

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.