Green-Synthesized Mg-Substituted PrFeO3 Perovskites via Waste-Derived Precursors for Acetone Gas Sensing

Anupinder Singh^1*Shiffali Middha¹Amritpal Singh Nindrayog²Jagriti Mahajan¹Nitin Tandan³Satvir Singh³Indu Sharma^4,5Harmanjit Singh Dosanjh⁶Jaspal Singh⁷Aman Mahajan¹Nupur Prasad⁸Deekshant Varshney^10,9Lovepreet Singh^11*

• ¹Department of Physics, Guru Nanak Dev University, Amritsar, India
• ²Physics Department, Lyallpur Khalsa College, Jalandhar, India
• ³Department of Applied Sciences, CT University, Ludhiana, India
• ⁴Department of Physics, Career Point University - Hamirpur Campus, Hamirpur, India
• ⁵Center for Green Energy Research Career Point University, Hamirpur, India
• ⁶Lovely Professional University School of Chemical Engineering and Physical Sciences, Phagwara, India
• ⁷Department of Physics, Punjabi University, Patiala, India
• ⁸Research and Development Cell, Lovely Professional University, Phagwara, India
• ⁹Centre of research Impact and Outcome, Chitkara University, Rajpura, India
• ¹⁰Division of Research and Innovation, Uttaranchal University, Dehradun, India
• ¹¹Brain Science Institute, Korea Institute of Science and Technology, Seongbuk-gu, Republic of Korea

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 autocombustion 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 Fe 3+ /Fe 2+ charge compensation. Gas sensing measurements conducted between 60-210 °C identified 150 °C as the optimal operating temperature. The x = 0.3 composition demonstrated the highest response to acetone, with rapid response (33s) and recovery (20s) times. The sensor exhibited excellent repeatability at 50ppm 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.