화학 및 생물센서 : Sol - Coprecipitation 법에 의한 NO 감지응 WO3 센서 제조시 pH 의 영향

When particles are dissolved in solution, they have different zeta-potentials depending on pH. Zeta-potential has an influence on particle separation, which can control particle size. And the size of WO₃ particle affects the sensitivity of WO₃ sensor for detecting NO gas. Therefore we study influence of pH on NO-sensing WO₃ gas sensor fabricated by Sol-Coprecipitation method. As pH increases from 2 to 7, dynamic mobility of WO₃ precursor was increased. When pH was 7, it showed the largest distribution separation. It means when pH is 7, we can make WO₃ powder which has smaller particle size. And it is confirmed by particle size analysis of WO₃ powder, X-ray diffration result of WO₃ sensing layer and surface morphology. It also affect NO sensing characteristics of WO₃ gas sensor. The sensing film synthesized at pH 7 showed the largest sensitivity.