NH3, PH3 and AsH3 adsorption on alkaline earth metal (Be-Sr) doped graphenes: Insights from DFT calculations

To bring more safety assurance to human's life, effectively monitoring and suppressing NH3, PH3, and AsH3 gases is highly demanded. In this study, NH3, PH3 and AsH3 adsorptions on intrinsic and alkaline earth metal(AEM = Be, Mg, Ca, and Sr) doped graphenes are theoretically investigated. Adsorption energies analysis reveals that NH3, PH3 and AsH3 molecules are weakly adsorbed on intrinsic graphene, and lead to negligible changes in the electronic properties. The IIA element doped graphenes exhibit enhanced chemisorption towards NH3, PH3 and AsH3 molecules, due to the strong chemical reactivity of Be, Mg, Ca and Sr. Significant increase is observed in adsorption energies, charge transfers and orbital hybridizations of these adsystems. The sensitivity response and recovery time reveal that Mg doped graphene seems available for monitoring PH3 and AsH3. Sr doped graphene could be an ideal candidate for selectively sensitive NH3 detection under the mixed atmosphere of NH3, PH3 and AsH3 gases with appropriate recovery time. This study could facilitate the applications of AEM doped graphenes in the fields of NH3, PH3 and AsH3 detection.