Facile synthesis of Sn-doped MOF-5 catalysts for efficient photocatalytic nitrogen fixation

The utilization of Zn4O(1,4-benzenedicarboxylate)3 metal-organic framework (MOF-5) as a photocatalyst remains a substantial challenge owing to the limited stability under humid conditions and the low photocatalysis efficiency. Herein, a series of Sn-doped MOF-5 (Sn-MOF-5) were designed and fabricated for the photocatalytic N2 fixation using the specific T-tube photocatalysis reactor. Detailed characterization results illustrates that an appropriate amount of Sn4+ doping can not only enhance the specific surface area and reducing capacity of MOF-5, but also decrease the bandgap width and promote the separation of photogenerated carriers. Therefore, at a Zn:Sn ratio of 6, Sn-MOF-5 with the highest Sn4+ ratio shows superior catalytic performance with the ammonia (NH3) yield achieved 3912.76 μmol L−1 g−1 after 5 h, and the chemical stability is almost no decay after 15 h of continuous photocatalysis. This may offer a new strategy for improving catalytic performance and stability of MOF through doping Sn4+.