Two dimensional porphyrin-based metal–organic framework constructed on K4Nb6O17 microflowers for highly efficient charge transfer and photocatalytic hydrogen generation

By constructing Co(II) meso-tetra(4-carboxyphenyl) porphyrin-metal organic frameworks (CPMOF) on K4Nb6O17 microflowers, a special K4Nb6O17-based nanocomposite (K4Nb6O17/CPMOF) was achieved. The CPMOF constructed on the K4Nb6O17 microflowers was employed as strong light-harvesting sensitizer and electron transfer carrier, and thus the light absorbance range of K4Nb6O17 microflowers could be efficiently expanded as well as relatively high separation of photo-generated charges was obtained. Only introducing 9 wt% CPMOF, the K4Nb6O17/CPMOF nanocomposite showed about 17.5 times higher photocatalytic activity than that of K4Nb6O17 microflowers. Impressively, the stability of the K4Nb6O17/CPMOF can be improved due to the protection of the K4Nb6O17 microflowers and the constructed heterostructure. The reason for the enhanced photocatalytic activity was explored in detail. This research will provide a new perspective for the rational design of oxysalt-based photocatalysts used in energy conversion.