A comparative study on the VOCs gas sensing properties of Zn2SnO4 nanoparticles, hollow cubes, and hollow octahedra towards exhaled breath analysis

[Display omitted] •Zn2SnO4 nanoparticles, hollow cubes, and hollow octahedra were synthesized.•The VOC gas sensing properties of the three morphologies were compared.•The hollow octahedra showed the best acetone sensing performance, with the detection limit of 0.67 ppb.•The fabricated sensor is effective for the detection of VOCs in diabetic diagnosis applications.•Gas-sensing mechanism of the three morphologies was also discussed. People in developing countries are facing various fatal diseases like cancer, pneumonia, tuberculosis and especially diabetes due to the lack of low cost and effective diagnosis methods. Design and fabrication of effective materials for VOC gas sensor applications towards exhaled breath analysis in diabetic diagnosis is challenging because the gas sensing performance of metal oxides is dependent on their composition, structure, and morphology. Here, Zn2SnO4 (ZTO) nanoparticles, hollow cubes, and hollow octahedra were successfully synthesized for VOCs gas sensing applications. The synthesized materials were characterized by advanced techniques while the gas sensing properties of the synthesized materials were tested for the detection of VOCs (acetone, ethanol, methanol), NH3, H2, and CO over the temperature range of 350 °C–450 °C. The ZTO hollow cubes and hollow octahedra exhibited exceptionally high sensitivity towards 125 ppm acetone at 450 °C with the response values of 47.80 and 63.93, respectively. The ZTO sensors also exhibited good selectivity and stability, with the theoretical calculation detection limits towards acetone being 175 ppb and 0.67 ppb for hollow cubes and hollow octahedra, respectively. The developed ZTO sensor maintained its performance after several tens of testing cycles, and few months storage in ambient air. The high gas-sensing performance of the ZTO hollow cubes and hollow octahedra to acetone was explained by an increase in the pore size, porosity, and oxygen vacancies. The above results suggest that the ZTO hollow octahedra and the hollow cubes are promising sensing materials for the detection of VOCs in diabetic diagnosis applications.