Highly dispersed Cu2O quantum dots (about 2 nm) constructed by a simple functional group anchoring strategy boost the photocatalytic water splitting ability by 72 times

Abstract

Quantum dot (QD) co-catalysts can efficiently facilitate photocatalytic processes due to their extremely small size and unique optical properties. However, metal quantum dots have high surface energy and tend to agglomerate to form larger particles during the synthesis process and lose their advantages. Herein, a simple and novel functional group anchoring strategy was designed for the in situ synthesis of small-sized and uniformly dispersed Cu₂O QDs on commercial P25 surfaces. The average diameter of the obtained Cu₂O QDs is only 1.8 nm. The hydrogen production rate of the photocatalysts deposited with Cu₂O QDs is increased by 72 times compared with that of pristine commercial P25. The experimental results demonstrate that the OH-group on the surface of commercial P25 is able to act as an anchor point to induce the in situ generation of Cu₂O QDs. After deposition of Cu₂O QDs, the light absorption range of commercial P25 is extended to the visible region. In addition, the photogenerated carrier separation efficiency and photoreduction capacity are significantly enhanced after deposition of Cu₂O QDs on the surface of commercial P25. This work provides a new strategy for the synthesis of small-sized and uniformly dispersed nanomaterials.