Methanol gas sensing properties of transition metals (V, Cr, and Mn)-doped BC3 flake

Volatile organic compounds (VOCs) cause a considerable risk to human life, and it is vital to introduce highly efficient VOC biosensors. Methanol (CH₃OH) was identified as a vital biomarker, showing significant elevation in both lung cancer and COVID-19 patients. Two-dimensional (2D) semiconductor gas sensors offer benefits such as excellent sensitivity, resistance to high temperatures and stability. In the present study, we explored methanol adsorption on the pristine and transition metal (TM)-doped (Sc, Ti, V, Cr, and Mn) C3B 2D flakes with the density functional theory (DFT) technique. Our results revealed that the V-, Cr-, and Mn-doped C3B show larger adsorption energy values as compared to the pristine C3B surface. The change of band gap energy of surfaces after methanol adsorption is obtained between 40 and 400 %. Besides, results show that methanol has a quick recovery at room temperature. The work function variation of studied flakes upon methanol adsorption has been also investigated and results show that V-, Cr-, and Mn-doped C3B systems are sensitive to methanol gas molecule. This work suggests that the C3B-based flakes can be used as a biosensor to identify VOC biomarkers such as methanol.