Fabrication of hollow porous ZnO@ZnS heterostructures via hydrothermal method and enhanced gas-sensing performance for ethanol

Heterostructures with great modulation of electron transfer afford a great opportunity for gas-sensing applications. Herein, a hollow porous ZnO@ZnS core-shell structure with high gas-sensing performance has been successfully hydrothermally synthesized. The phase composition and the morphology of the as-prepared products were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope and energy dispersive X-ray spectroscopy. The results show that the pure ZnO and the ZnO@ZnS appear a mesoporous structure and a hollow porous structure, respectively. Gas-sensing measurements show that the gas-sensing performance of the ZnO@ZnS based sensor is obviously higher than that of the pure ZnO, and it has a high selectivity, quick response-recovery and stability to ethanol. Its response reaches 114.2 to 100 ppm ethanol, and the response and recovery time is 3 s and 8 s to ethanol, respectively. The gas-sensing enhancement of the ZnO@ZnS can be attributed to the Schottky barrier at the interface of the ZnO@ZnS and the special hollow porous structure. The strategy put forward is generally applicable to design efficient ethanol sensors with optimized sensing performances. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

A hollow porous ZnO@ZnS core-shell structure was successfully synthesized hydrothermally, showing high gas-sensing performance with high selectivity, quick response-recovery, and stability to ethanol. The gas-sensing enhancement can be attributed to the Schottky barrier at the interface and the special hollow porous structure of ZnO@ZnS.