With the growing concern over the adverse effects of
environmental
pollution on human health, the combination of environmentally friendly
and nontoxic biomaterials with metal oxide semiconductor materials
for electronic devices has emerged as a prominent trend in current
research. In this study, we utilized 150 mg apple biotemplates to
assist in the hydrothermal synthesis of ZnO nanospheres. It successfully
achieved high sensitivity for detecting 35 and 350 ppb NO2 at room temperature, with responses of 13.74 and 132.44%, respectively.
Simultaneously, the 5-cycle repeatability and multiple-gas selectivity
exhibited significant improvements. The ZnO nanospheres demonstrated
enhanced sensing performance compared to pure ZnO nanorods, which
is attributed to the following mechanisms: reason I, the modified
surface morphology increasing the surface-to-volume ratio; reason
II, an increase in oxygen vacancies, leading to reduced crystallinity
and a higher electron concentration; reason III, incorporation of
carbon elements on the nanostructure surface to increase active sites.
The novel gas sensor assisted by the apple pectin biotemplate offers
a promising solution for NO2 gas detection, featuring low
operating temperatures, low concentrations, and high response sensitivity.