Simultaneous sensitization and hole activation in carbon nitride polymer sensitized TiO2

Abstract

Experimental and theoretical methods have combined to explore the role of carbon nitride polymer (CNP) in the photocatalytic performance of CNP-sensitized TiO₂ (P25). In this work, CNP rather than its precursors has been used to directly sensitize TiO₂ at 170 °C based on acid–base interaction and the photocatalytic performance of CNP-sensitized TiO₂ is evaluated by degradation of methyl orange under visible light irradiation. The obtained results show the photocatalytic performance of CNP-sensitized TiO₂ is obviously stronger than TiO₂ and CNP. The high performance results not only from transferring the photoinduced electrons from CNP to the conductivity band (CB) of TiO₂ and the increased separation efficiency of photoinduced electrons and holes, but also possibly from hole activation. Hole activation may result from the interaction between TiO₂ and CNP, which increases the oxidation ability of the photoinduced hole that leaves the CNP skeleton after light irradiation.