Effect of Pt cocatalyst on visible light driven hydrogen evolution of anthracene-based zirconium metal-organic framework

In this work, an anthracene-based MOF, Zr-ADBEB, was prepared by coordination reaction of zirconium chloride and 4,4'-anthracene-9,10-diylbis(ethyne-2,1-diyl) dibenzoic acid (ADBEB). After the loading of different amount of Pt nanoparticles by post chemical reduction of hexachloroplatinic acid with sodium borohydride, the MOF presented greatly improved activity towards visible light hydrogen (H-2) evolution. It was identified that band bending of the MOF is downward towards surface, which is effective to promote separation of the photo-generated charge carriers and transportation of the photogenerated electrons from the MOF to the Pt cocatalyst to contribute to the H-2 evolution. The Zr-ADBEB MOF photocatalyst decorated by optimal amount of Pt cocatalyst, i.e., 1.0 wt%, exhibited a H-2 evolution rate as high as 704 mu mol.h(-1).g(-1), ca. 220 times of that of pristine Zr-ADBEB MOF (3.2 mu mol.h(-1).g(-1)).