Uniform decoration of UiO-66-NH nanooctahedra on TiO electrospun nanofibers for enhancing photocatalytic H production based on multi-step interfacial charge transfer

• Published in: Dalton transactions : an international journal of inorganic chemistry 2021-05, Vol.5 (18), p.6152-616
• Main Authors: Wang, Jie, Sun, Zhengang, Jiang, Xiaoyi, Yuan, Qing, Dong, Dapeng, Zhang, Peng, Zhang, Zhenyi
• Format: Article
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/d1dt00743b

Metal-organic framework (MOF) materials have been extensively incorporated with inorganic semiconductor photocatalysts to improve their photocatalytic activity through an efficient charge transfer process across their heterointerface. In this work, octahedral UiO-66-NH 2 MOFs with edge-lengths of 110-330 nm are uniformly decorated on the surface of TiO 2 electrospun nanofibers by a traditional solvothermal method combined with activation pretreatment. Before the solvothermal growth of UiO-66-NH 2 , the TiO 2 electrospun nanofibers were activated in NaOH solution to etch the TiO 2 surface for allowing the exposure of lattice oxygen. The exposed lattice oxygen on the TiO 2 surface could interact with the MOF precursor of Zr 4+ ions, thus enabling octahedral UiO-66-NH 2 to grow uniformly on the surface of TiO 2 nanofibers with an intimate Ti-O-Zr hetero-interface. Such an intimate hetero-interface provides an effective channel for boosting the electron transfer between UiO-66-NH 2 and TiO 2 in their heterostructure. Thus, the UiO-66-NH 2 /TiO 2 (anatase) heterostructures exhibited enhanced photocatalytic activity for H 2 production as compared to either TiO 2 (anatase) nanofibers or UiO-66-NH 2 nanooctahedra in the presence of Rhodamine B (RhB) as a sensitizer under visible light irradiation. In particular, the decoration of UiO-66-NH 2 nanooctahedra on anatase/rutile mixed TiO 2 nanofibers could induce further enhancement of the photocatalytic H 2 production. The enhanced photocatalytic activity is attributed to the multi-step continuous interfacial transfer of photoinduced electrons with the way of RhB → UiO-66-NH 2 → TiO 2 (anatase) → TiO 2 (rutile). Octahedral UiO-66-NH 2 MOFs are uniformly decorated on the surface of TiO 2 nanofibers. The intimate Ti-O-Zr hetero-interface provides an effective channel for boosting the electron transfer between UiO-66-NH 2 and TiO 2 in their heterostructure.