HCl gas sensor based on nano-WO_3

The semi conductive HCl gas sensor based on WO3 is prepared by dopping,and the characteristic of that is studied.The special structure WO3 is produced from Na2WO3 and strong hydrochloric acid by sol-gel method.It's found by XRD,SEM and TEM that the structure is sheet and incompact and the mean particle is about 17nm.The sensitivity to HCl can be improved greatly by dopping Al2O3 but the stability and selectivity is poor.Although the sensitivity is reduced by dopping a little ZnO,the stability can be improved greatly.The sensitivity to NO2 can be reduced by increasing the heating voltage.The sensitivity mechanism and characteristic of WO3 is analyzed.