Influence of defect and doping on the sensitivity and adsorption capacity of Zr2CO2 toward PH3 gas

In this study, the potential application of the ZrCO-MXene structures as PH sensors and adsorbents for industrial or living applications was investigated using the first-principles approach of density functional theory (DFT). The adsorption of PH on pristine, O-defected, and transition metal (TM; such as Cr, Mn, Fe, Co, Y, Mo, Ru, Rh)-doped ZrCO structures was explored. The results showed that the introduction of TM dopant improved the ZrCO activity more than the O-vacancy. The large adsorption energy, short interaction distance, and high charge transfer suggested chemisorption of PH molecules on TM-doped ZrCO. After the PH molecule was adsorbed, the band gap of ZrCO with O-vacancies, Co-doped ZrCO, and Ru-doped ZrCO decreased by 0.132 eV, and increased by 0.065 eV, 0.073 eV, respectively. The changes in band gap generated an electrical signal that were used for PH detection; thus, ZrCO with O-vacancies and Co– and Ru-doped ZrCO can be used as effective PH sensors because of their high sensitivity. Fe- and Rh-doped ZrCO also showed promising function as adsorbents for PH gas molecules because of their high adsorption stabilities and long recovery times. After adsorption of six PH molecules, their adsorption energies on Fe- and Rh-doped ZrCO were −1.142 eV and −1.135 eV, with recovery times of 1.49 × 10 s and 1.12 × 10 s, respectively. The findings of this study offer novel insights for the development of MXene-based sensors and adsorbents.