Highly enhanced methanol gas sensing properties by Pd0.5Pd3O4 nanoparticle loaded ZnO hierarchical structures

Abstract

Pd_0.5Pd₃O₄ nanoparticle loaded ZnO hierarchical architectures have been successfully synthesized via a facile solution route at room temperature followed by a subsequent thermal treatment. Morphology and component characterizations reveal that Pd_0.5Pd₃O₄ nanoparticles are uniformly deposited on the surface of the ZnO hierarchical architecture. A gas sensor based on the as-prepared Pd_0.5Pd₃O₄ loaded ZnO hierarchical architecture shows excellent gas sensing performances in terms of fast response time (1 s), recovery time (5 s) and a high sensitivity for 50 ppm methanol at a relatively low temperature, which are evidently modified by the appropriate decoration of Pd_0.5Pd₃O₄ nanoparticles in comparison with pure ZnO. The enhanced gas sensing performances are attributed to the appropriate sensitization effect of Pd_0.5Pd₃O₄ nanoparticles. A multistage reaction formation mechanism of such flowerlike hierarchical architecture, and the morphology-dependent gas sensing mechanism are proposed.