Enhancing photocatalytic activity in monolayer MoS2 by charge compensated co-doping with P and Cl: First principles study

Abstract

Recently, P doped ultra-thin MoS2 film has demonstrated enhanced photocatalytic property. However, the flat impurity level within the bulk band gap acting as the recombination center hinders the photocatalytic performance. This impurity level is induced by P, whose outer shell has one electron less than S. Thus, charge compensated doping P and Cl together is adopted here to remove the impurity levels. Using first principles study, we report the doping site, formation energy, electronic and photocatalytic properties of P and Cl co-doped monolayer MoS2. It is found that P and Cl atoms tend to settle at S sites (PS and ClS) instead of Mo sites or interstitial. Interestingly, PS-ClS co-doping can enhance the photocatalytic activity of MoS2 by removing the flat impurity level and increasing the number of catalytic active sites.