Selective ammonia sensing response of vanadium doped cerium oxide nanorods wrapped reduced graphene oxide electrodes at room temperature

Abstract

• Cost effective and simple two step hydrothermal method was followed for synthesis. • Vanadium doped cerium oxide nanorods were anchored over the rGO layers. • Economically reliable printed circuit board was used as electrodes. • Fabricated electrode exhibits maximum sensitivity of 85 % towards 50 ppm of NH 3 at 40 % RH. • The lowest detection limit was 10 ppm and the electrodes have long term stability of 99 % for the period of 50 days. Drastically increasing air pollution has been perceived as a vital agitation and its detection has become an unavoidable area of interest for many researchers. Room temperature operative gas sensing electrodes with long term stability and highly selective feature are crucial to meet the miniaturization of gas sensing devices. Ammonia (NH 3 ) is an irritant gas consists of pungent odor in nature. Here, we report a synthesis method for the composite of vanadium doped cerium oxide (VCeO 2 ) wrapped reduced graphene oxide (rGO) for NH 3 sensing via two step sonication assisted hydrothermal method. The physiochemical and morphological characterization were examined well in detail. The results indicate the high crystalline VCeO 2 nanoparticles were assembled as nanorods over the rGO sheets in a regular manner. The chemically active defect sites on the rGO sheets enhance the gas molecule adsorption and provide high electrical conductivity. This sensing electrode was exposed towards various target gases and it offered excellent selectivity and good sensitivity of 85 % towards 50 ppm of NH 3 with response time 104 s and recovery time 47 s. In addition, this electrode maintains 99 % of its initial sensitivity after 50 days which proves its high stability due to the room temperature operation. This prepared composite material will be a good candidate against NH 3 detection.