Construction of terbium oxide/polymer carbon nitride heterojunction for boosting photocatalytic overall water splitting without cocatalyst

Abstract

Photocatalytic overall water splitting is an appealing approach to resolve the fossil energy crisis. Though polymeric carbon nitride (CN) is an excellent photocatalyst, it displays a low activity for photocatalytic pure water splitting. Herein, we successfully prepared novel Tb4O7/CN heterojunctions with a sandwich structure via a simple one-step calcination method. There is a strong interaction between Tb4O7 and CN. Introduction of Tb4O7 on CN promotes the separation and transport of photoexcited charge carrier, and increases the specific surface area, light utilization and hydrogen evolution reaction (HER) activity. Consequently, the optimal Tb4O7/CN heterojunction exhibits a greatly promoted photocatalytic hydrogen evolution activity with a rate of 48 μmol h−1 g−1, about 48 time as high as that for single CN. Apparent quantum yield (AQY) for hydrogen evolution at 420 nm reaches 2.3%. The possible mechanism is presented. This research offers insights for developing the heterojunctions of rare earth oxide and CN.