Enhanced acetone sensing performance of Au nanoparticle modified porous tube-like ZnO derived from rod-like ZIF-L.

Metal oxide semiconductors with a porous hollow structure have received great attention in many fields. In this work, a facile preparation method of porous tube-like ZnO (PT-ZnO) was developed by annealing rod-like ZIF-L at high temperature, and the formation mechanism of the tube-like structure was discussed in detail. The corresponding gas sensing performances were determined adopting acetone as the target gas. Gas-sensing test results show that PT-ZnO has better acetone sensing performance than that of porous plate-like ZnO (PP-ZnO) derived from leaf-like ZIF-L, resulting from the unique tube-like structure and larger amount of adsorbed oxygen. It is found that the introduction of Au nanoparticles greatly improves the acetone sensing performance, which can be attributed to the activation of acetone by Au and the increased amount of adsorbed oxygen. Au/PT-ZnO has the largest amount of adsorbed oxygen which even becomes the dominant oxygen species on the surface of PT-ZnO, resulting in the best acetone-sensing performance.