AUTHOR=Middha Shiffali , Nindrayog Amritpal Singh , Mahajan Jagriti , Tandon Nitin , Singh Satvir , Sharma Indu , Dosanjh Harmanjit Singh , Singh Jaspal , Mahajan Aman , Prasad Nupur , Varshney Deekshant , Singh Lovepreet , Singh Anupinder TITLE=Green-synthesized Mg-substituted PrFeO3 perovskites via waste-derived precursors for acetone gas sensing JOURNAL=Frontiers in Materials VOLUME=Volume 12 - 2025 YEAR=2025 URL=https://www.frontiersin.org/journals/materials/articles/10.3389/fmats.2025.1655749 DOI=10.3389/fmats.2025.1655749 ISSN=2296-8016 ABSTRACT=The detection of volatile organic compounds (VOCs), particularly acetone, is crucial for environmental monitoring and biomedical diagnostics. In this study, Mg-substituted PrFeO3 perovskite oxides (PrMgxFe1-xO3, x = 0.1, 0.2, 0.3) were synthesized via a sol-gel auto-combustion route using Fe and Mg precursors extracted from waste-derived materials, offering a sustainable and cost-effective synthesis pathway. Pristine PrFeO3 exhibited p-type semiconducting behavior; however, Mg incorporation induced a shift to n-type conduction, attributed to the generation of oxygen vacancies and Fe3+/Fe2+ charge compensation. Gas sensing measurements conducted between 60 °C and 210 °C identified 150 °C as the optimal operating temperature. The x = 0.3 composition demonstrated the highest response to acetone, with rapid response (33 s) and recovery (20 s) times. The sensor exhibited excellent repeatability at 50 ppm acetone, moderate selectivity toward ethanol, propanol, and DMF, and demonstrated good long-term stability. The VOC sensing performance is attributed to defect engineering via Mg substitution, increased oxygen vacancy concentration, and improved charge carrier dynamics. These results highlight the potential of waste-integrated perovskite sensors in advancing sustainable gas-sensing technologies.