Metal oxide hollow heterojunctions derived from bimetalorganic frameworks for efficient urea photosynthesis

Abstract

As an important chemical in agriculture, the green synthesis of urea has attracted wide attention. However, developing simple and green synthetic strategy for urea synthesis remains challenging. In this study, we developed a novel metal oxide hollow heterojunction for efficient photocatalytic urea synthesis. By calcining a bimetallic MUV-10 MOF precursor in air atmosphere, the metal oxide hollow heterojunction TiO 2 /Mn 2 O 3 (denoted as TMO) was successfully prepared, while the octahedral structure has been well preserved. Among these catalysts, the bimetallic oxide TMO-8 exhibits the highest light-harvesting capability and photogenerated carrier separation efficiency, enabling efficient photocatalytic urea synthesis from CO 2 and NH 3 . Under visible light irradiation, TMO-8 hollow heterojunction achieved a high urea production rate of 93 µmol g -1 h -1 , which surpassed the state-of-the-art photocatalysts. This study provides a new strategy for designing efficient heterojunction photocatalysts and offers an efficient pathway for artificial photosynthetic urea synthesis under mild conditions.