Significant improvement in the acetone sensing performance of Ag-decorated ZnO porous nanosheets through defect engineering by Li-ion implantation

Defect engineering by Li-ion implantation has been extensively studied in electrocatalysis, photocatalysis, and energy storage devices. Here, we provide the first experimental evidence that Li-ion implantation improves the acetone sensing performance of ZnO-based sensors. The morphological structure of the solvothermally synthesized Ag-decorated ZnO porous nanosheets (Ag-ZnO PNSs) was controlled by Li-ion insertion/extraction at various discharge voltages. The generation of nanocracks caused by the electrochemical reaction between ZnO and Li significantly improved the sensing performance. The nanocracked Ag-ZnO PNSs had a much higher sensing response (∼319) to 10 ppm acetone than the ZnO nanoparticles, bare ZnO PNSs, and bare Ag-ZnO PNSs. At the optimum operating temperature of 400 °C, the low detection limit was 0.1 ppm. The significant improvement in the acetone sensing performance of nanocracked sample is attributed to the simultaneous increase in oxygen vacancies and specific surface area, as well as the Ag catalytic effect. Furthermore, the nanocrack structures were found to be stable even after repeated measurements at high temperatures. Our research found that Li-ion implantation is an effective method for improving the gas sensing performance of metal oxide-based sensors, and that nanocracked Ag-ZnO PNSs can be a promising candidate material for use as acetone sensor applications.