Interfacial Zn─O─Ti Sites for Efficient Photocatalytic Urea Synthesis from CO <sub>2</sub> and N <sub>2</sub>
Jiaojiao Fang, Yan Wu, Huiling Hu, Hangmin Xu, Anni Zhu, Yukai Chen, Xingwang Zhu, Junjie Mao
Abstract
Abstract Urea photosynthesis from CO 2 and N 2 has profound environmental and energy implications. However, the simultaneous activation of CO 2 and N 2 , along with the promotion of C─N bond formation, remains a major challenge. Herein, the asymmetric interfacial sites (Zn─O─Ti) were engineered by building oxygen atom bridges between ZIF‐8 and MIL‐125 to enable efficient photocatalytic urea synthesis. The optimized Zn─O─Ti interface structure achieves a urea yield of 130 µmol g −1 h −1 in pure water and an apparent quantum yield of 5.52% at 350 nm, outperforming most materials reported for urea photosynthesis. Mechanistic studies reveal that Zn sites catalyze the conversion of CO 2 to *CO species, while Ti sites adsorb and activate N 2 to generate *NH–NH species. The asymmetric interfacial sites lower the energy barrier for the coupling of *CO and *NH–NH to form *CONH 2 intermediates, thereby promoting urea photosynthesis. This work provides significant insights into designing interfacial asymmetric sites to facilitate photosynthetic organic chemicals for upgrading the nitrogen cycle.