Study On Controllable Synthesis And Gas Sensing Properties Of Nanobelt Networks Of Nano-vanadium Oxide

In biological,chemical and other industrial production and road transportation,it is necessary to take reliable detection to monitor ethanol gas due to the volatile and flammable properties.Therefore,research and development of the ethanol sensor with high sensitivity,selectivity and stability has important practical significance.As the wide bandgap n-type semiconductor,V₂O₅ sensor in the detection of ethanol gases has shown great prospect.In this paper,the preparation of a new kind of nanobelt networks structure,and the ethanol-sensing properties of the as-obtained device were evaluated.Here,EDTA acts as chelating reagent and capping agent,ultrathin VO2 nanobelts were formed through a direct seed-induced controllable preparation by hydrothermal method on the substrate attached a pair of patterned Pt electrodes,and gas sensor based on V₂O₅ ultrathin nanobelt networks with rough alignment feature were prepared with the mild annealing of ultrathin VO2 nanobelts at 350°C in air.Annealed induction layer and the concentration of EDTA are found to play crucial roles in the formation of aligned and ultrathin nanobelts.The nucleation and growth mechanism involved the formation of nanobelts and nanoplates are proposed based on the Synergic effect of the induced seed-layer and EDTA-oriented growth.The good gas-sensing properties of the V₂O₅ nanobelt networks-based sensor was investigated from 20 oC to 300 oC over ethanol concentrations ranging from 3 to 500 ppm,and the V₂O₅ nanobelt networks-based sensor can detect the ethanol concentrations as low as 5ppm and 3ppm at 20? and 250°C.The V₂O₅ sensor exhibits high sensitivity,fast response and recovery characteristics and good reversibility at the optimal working temperature at 250°C.From room temperature to 300 oC,V₂O₅ nanobelt networks-based sensor shows p to n response characteristic reversal with the increase of temperature.