GaN NPs modified radial porous ZnO microspheres for low-temperature and high-efficiency detection of triethylamine

So far reported most semiconductor metal oxide-based triethylamine (TEA) gas sensors need to work at high operating temperature, which not only lead to power consumption but also shorten the service life of sensors. Therefore, there is a high requirement to develop convenient TEA sensors with low operating temperature. In this work, hierarchical radial porous GaN/ZnO n-n heterostructure was successfully prepared by surface modification of ZIF (Zeolitic Imidazolate Framework)-61 microspheres with GaN nanoparticles (NPs) via electrostatic attraction effect combined with a subsequent pyrolysis. The resultant GaN/ZnO heterostructure presents significantly improved TEA sensing performance compared with pure ZnO, reflecting in reduced operating temperature (80 ℃) and higher response value of 24.18 towards 50 ppm TEA, likewise good selectivity and stability. This can be attributed to the highly permeable structure and large surface area of GaN/ZnO heterostructure, accelerating the adsorption and diffusion of gases. The GaN NPs decorated on ZnO facilitate electron transfer and adsorption of reactive oxygen species. The in-situ DRIFTs was conducted to investigate the oxidation of TEA over GaN/ZnO surface. The work demonstrates an electrostatic interaction strategy combined with pyrolysis to obtain a novel radial porous GaN/ZnO hierarchical microspheres showing intriguing TEA sensing properties.