Non-covalent doping of graphitic carbon nitride with ultrathin graphene oxide and molybdenum disulfide nanosheets: An effective binary heterojunction photocatalyst under visible light irradiation

A proof of concept integrating binary p-n heterojunctions into a semiconductor hybrid photocatalyst is demonstrated by non-covalent doping of graphite-like carbon nitride (g-C₃N₄) with ultrathin GO and MoS₂ nanosheets using a facile sonochemical method. In this unique ternary hybrid, the layered MoS₂ and GO nanosheets with a large surface area enhance light absorption to generate more photoelectrons. On account of the coupling between MoS₂ and GO with g-C₃N₄, the ternary hybrid possesses binary p-n heterojunctions at the g-C₃N₄/MoS₂ and g-C₃N₄/GO interfaces. The space charge layers created by the p-n heterojunctions not only enhance photogeneration, but also promote charge separation and transfer of electron-hole pairs. In addition, the ultrathin MoS₂ and GO with high mobility act as electron mediators to facilitate separation of photogenerated electron-hole pairs at each p-n heterojunction. As a result, the ternary hybrid photocatalyst exhibits improved photoelectrochemical and photocatalytic activity under visible light irradiation compared to other reference materials. The results provide new insights into the large-scale production of semiconductor photocatalysts. © 2014 Elsevier Inc.