Functionalization of nanoparticles into nanofibers is attractive for improving the performance of gas sensing, as gas sensing characteristics of metal oxide nanofibers are significantly influenced by the size and dis-tribution of catalysts. Usually, the nanoparticles are easily aggregated into larger secondary particles, which de-grade the catalytic effect. On the other hand, the Pt, nanoparticles shown in this work are very minute, so they are uniformly distributed due to their repulsion interaction in the course of fabrication.
In this work, we have successfully fabricated Pt nanoparticles with very small nano-size (average, 2 nm) using the templating nanocage and developed ZnO nanofibers and NiO nanofiberss functionalized with well distributed small Pt nanoparticles, respectively. ZnO nanofibers and NiO nanofibers were fabricated via electrospinning, which is facile method for mass production of nanofibers. The evaluation of gas sensing properties has been proceeded using acetone, ethanol, H2S and toluene gases at highly humid atmosphere (95% RH), which is similar to human exhaled breath. The obtained Pt functionalized ZnO nanofibers show greatly improved response for acetone gas at high temperature; in addition, Pt functionalized NiO nanofibers also show greatly improved response for H2S gas at low temperature. This work verifies the outstanding catalytic effect of finely dispersed small Pt nanoparticles into both n-type ZnO nanofibers and p-type NiO nanofibers, respectively. The results imply the possibility of further improvement in the performance of exhaled breath gas sensor by optimal functionalization nanofibers with various catalysts and as well as well-dispersed Pt nanoparticles.
가스센서의 감지소재로써 금속산화물 반도체가 많이 사용되고 있으며, 가스감지특성을 향상시키기 위하여 촉매를 결착화 시키는 등의 연구가 많이 수행되고있다. 이때 결착화되는 촉매의 크기와 분산도도 매우 중요하다. 본 연구에서는 단백질 희생층을 이용하여 제조한 매우 작고, 분산이 잘된 백금 촉매를 매우 쉽고 간단한 방법으로 제조하였다. 위의 방법으로 제조된 백금 촉매를 아연산화물, 니켈산화물에 결착시켰을 때, 백금 촉매가 결착된 아연산화물은 높은 온도에서 아세톤 가스에, 백금 촉매가 결착된 니켈산화물은 낮은 온도에서 황화수소 가스에 대한 특성이 향상되는 것으로 부터 뛰어난 촉매 효과를 확인하였다. 본 연구의 감지소재는 날숨 센서에 응용하기 위한 것으로, 사람의 날숨과 비슷한 습도인 95% 상대 습도에서 수행되었으며, 추후 감지소재와 촉매의 최적화 조건을 통하여 날숨센서에 적용시킬 수 있는 가능성을 확인하였다.
