Hierarchical CaTiO3 microspheres for acetone sensing

The development of a suitable chemical route for the synthesis of exotic nanoarchitectures as a promising candidate for reliable volatile organic compounds (VOCs) monitoring continues to be a formidable task. Acetone (C 3 H 6 O) is one such compound that is commonly found as a solvent in paints, resins, cellulose acetate, and even in the human breath condensate of a diabetic patient. Despite the colossal attention, innovations in VOCs monitoring from viewpoints of materials science are imperative and alluring in the fields of medical devices, and indoor air quality. Herein, we report on acetone sensing characteristics based on calcium titanate (CaTiO 3 ) in the form of hierarchical microspheres synthesized using the solvothermal technique at 200 °C for 18 h. The microspheres depicted a highly polydispersed morphology with a shape and texture of walnut ranging from 100 to 700 nm. Acetone sensing parameters were investigated by comparing hierarchical microspheres with a control sample, thus validating the dependency of sensitivity on the morphology. Hierarchical nanostructures with large surface area (91.45 m 2 /g), when compared to the control microsensor showcased 6-fold enhancement in the sensitivity, superior selectivity (10 gases), excellent long term stability (21 days), minimum CoV (1.18%) with quick response kinetics (τ Res =75 and τ Rec =95 s) at 160 °C. The enhanced performance depicted here by the hierarchical microsensor is foreseen to make it highly suitable for applications requiring low ppm acetone detection in a dry and humid environment. • Solvothermal synthesis of hierarchical CaTiO 3 microspheres at 200 °C for 18 h. • Morphology-dependent acetone sensing at 160 °C in dry and humid conditions. • Enhanced sensor response and response kinetics towards 0.3–200 ppm concentration. • Excellent stability and selectivity in presence of 10 industrial relevant gases. • Improved sensing performance attributed to hierarchical morphology & high surface area.