Ordered Mesoporous Ag–ZnO@g-CN Nanohybrid as Highly Efficient Bifunctional Sensing Material

Abstract

The development of highly efficient and multifunctional sensors for accurately detecting indoor climate has always remained a challenging task. In this work, an important progress for nanocasting synthesis of ordered mesoporous Ag–ZnO-loaded graphitic carbon nitride (g-CN) prepared through template inversion of mesoporous silica, KIT-6, is presented. The cubic 3D ordered mesoporous Ag–ZnO@g-CN nanohybrid demonstrates excellent sensitivity, rapid response/recovery (5.1/2 s), excellent reversibility (0.3%), high stability, and negligible hysteresis (0.5%) to relative humidity (%RH) in the 11–98%RH range. Besides, it shows outstanding selective response (R = Ra/Rg) of 62.4 and 37.6 under dry and 90%RH environment, respectively, along with a fast response/recovery (16.1/10.5 s) time toward detection of acetone at 200 °C. In addition, the sensor shows excellent response at significant lower operating temperatures (R = 3.2 at 60 °C and R = 6.7 at 80 °C) to 50 ppm acetone gas. Compared to mesoporous Ag–ZnO, the g-CN supported Ag–ZnO nanocomposite shows ≈1.8 times better response to acetone while marking an impressive reduction in optimized operating temperature by 50 °C. The findings in this study add insight and assist in the further optimization of this new class of 2D layered ordered mesoporous materials in realizing next-generation sensors with multiple utilities.