Fabrication And Study Of Vanadium Dioxide Nanorods Sensor

Technological revolution brought about economic benefits and civilization progress,yet it also caused the ecological imbalance and the environment problem.Acid rain,greenhouse effect and ozone layer caused a series of serious problems to the health of human,animal and plant.Studies show that nitrogen dioxide?NO₂?is the main source of acid rain and photochemical smog.As a main component of natural gas,methane?CH₄?mainly exists in mine and family kitchen.The explosion limit of CH₄ is4.9%-15.4%.More seriously,a small spark containing CH₄ component is sufficient to cause explosion,which seriously affect human health,and eventually lead to a serious explosion.Studies have reported that researchers using metal oxide semiconductor as a sensitive material to produce sensitive element,such as WO₃,ZnO and SnO₂ et al.Vanadium dioxide?VO₂?has attracted great attention of scientists for its unique characteristics of semiconductor-metal transition?SMT?,which is promising in optical switching devices,energy manager devices and infrared sensors,etc.Compared to other metal oxide,low resistance of VO₂ has good sensitive characteristic at RT,which makes VO₂ very promising sensitive materials.Based on the above background,this paper deeply and systematically studied the preparation of VO₂ nanostructure sensitive element and its sensitive performance.VO₂ nanorods were prepared by chemical vapor deposition method combined with single variable control method.Research the influence of process parameters on nanoparticles morphology and sensitive properties by adjusting it.Two Pt electrodes were deposited on the surface of VO₂ nanorods by ultra high vacuum magnetron sputtering method,and we studied its NO₂ and CH₄ sensing properties at RT.Experimental results show that,the deposition temperature,deposition time and deposition pressure have effect on the process of preparing VO₂ nanorods.In the experimental range,we obtained best morphology of VO₂ nanorods when deposition temperature was 1000?,deposition time was 3h and deposition pressure was 1.5Torr,the length and diameter of free growth VO₂ nanorods reached 20?m and 60-70nm.Compared to VO₂ thin film,VO₂ nanorods has higher sensor response?34%?,faster response-recovery time?75s?,lower working temperature?25??.Subsequent surface deposited Au nanoparticles can further enhance the sensitive properties of the VO₂nanorods.