Comparison of synthesis strategies for the preferential detection of acetone by defect-rich Eu-doped Zn2SnO4 nanostructures

Summary of Acetone sensing performance demonstrated by Zn 2 SnO 4 :Eu. • Comparison of synthesis methods for Eu-doped Zn 2 SnO 4 nanostructures to tailor gas-sensing properties. • The coprecipitation method produces defect-rich, mesoporous structures with abundant active sites and lattice dislocations. • Achieved high acetone selectivity and sensitivity at low concentrations (0.08–2.5 ppm). • Ultra-low detection limit of 3.4 ppb, demonstrating potential for real-time breath analysis. • Excellent repeatability and long-term stability, making it a strong candidate for practical gas sensor applications. There is an urgent need and increasing demand for developing, innovative, and reliable gas sensor devices for non-invasive methods to diagnose and monitor acetone in diabetic patients. Thus, herein, the effect of the synthesis strategy on the acetone sensing performance was investigated between the coprecipitation, autoclave, and microwave-assisted hydrothermal methods. Among these, the coprecipitation approach demonstrated superior properties, including radiative magnetic dipole transitions ( 5 D 0 → 7 F 1 ) from an excited state to a ground state of Eu 3+ ions. The nanostructures synthesized via coprecipitation revealed a plate-like hierarchical architecture, consisting of agglomerated tetragonal dipyramidal nanoparticles. These structures demonstrated outstanding selectivity and high sensitivity to acetone at 175 °C, detecting low concentrations (0.08–0.1 ppm) with a remarkably low detection limit of ∼ 0.0034 ppm (3.4 ppb) and rapid response-recovery times. The sensor exhibited consistent and reliable repeatability towards 16 cycles of response-recovery capabilities towards 2.3 ppm acetone vapour, and long-term performance stability. The remarkable performance was a combination of the advantages presented by the mesoporous surface with abundant active sites, lattice dislocations, and non-stoichiometry-related defects, achieved during coprecipitation, which facilitated acetone adsorption more effectively compared to the heat-treated methods. Additionally, introducing Eu 3+ ions into the lattice induced defects that are preferential for acetone molecule adsorption, consequently improving selectivity.