Urea photosynthesis over a MOF-on-MOF S-scheme heterojunction
Yamin Xi, Chaoqi Zhang, Tong Bao, Suzhao Liu, Tianxiang Wang, Wenjing Tu, Yuntian Guo, Yingying Zou, Chengzhong Yu, Chao Liu
Abstract
Photocatalytic nitrate reduction reaction coupled carbon dioxide reduction reaction holds great promise for sustainable urea synthesis, the design of photocatalysts with efficient C-N coupling and charge separation is crucial yet challenging. Herein, we report the synthesis of a novel MOF-on-MOF S-scheme heterojunction photocatalyst with interfacial dual active sites for efficient urea production via nitrate reduction reaction coupled carbon dioxide reduction reaction. The integration of semiconducting Zr-MOF and Co-MOF produces interfacial Co and Zr dual sites for NO3- activation and CO2 adsorption, synergistically promoting C-N coupling with reduced energy barriers. Besides, the S-scheme heterojunction enables the strong redox capability and facilitates the charge transfer. Consequently, the rationally designed MOF-on-MOF heterojunction achieves a high urea yield of 3523.4 μg g⁻¹ h⁻¹ and an apparent quantum yield of 1.16% at 365 nm in the absence of sacrificial agents. This work paves the way for the development of high-performance photocatalysts for urea production. This study reports the design of a MOF-on-MOF heterojunction catalyst with interfacial dual active sites for efficient urea production via photocatalytic co-reduction of nitrate and carbon dioxide.