The study on visible photocatalytic activity of an oxalate-extended Pb(II) coordination polymer

Under the hydrothermal method, a Pb(II) coordination polymer [Pb(ox)(phen)2]& BULL;5H2O 1 (ox = oxa-late, phen = 1,10-phenanthroline) was obtained. Ox ligands exhibit a m2-coordination mode, which connect Pb2+ centers into a 1-D single-chain with ancillary phen molecules. Interestingly, adjacent phen molecules between the chains exist & pi;...& pi; stacking interaction, which extend the 1-D chain into a 2-D supramolecular layer. Compound 1 showed outstanding photocatalytic performance and the degradation efficiency of methylene blue with H2O2 could reach 95.69% under the irradiation of visible light at pH = 10. In addition, 5 cycles of degradation experiments were also carried out, and it was found that the degradation efficiency values with and without H2O2 were reduced by 1.46% and 1.08%, respectively. It was also discussed that which free radical played the dominant role in the photocatalytic process. What's more, we speculated the possible reaction mechanism based on the Mott-Schottky curve. Meanwhile, the UV visible diffuse reflection of compound 1 was also investigated.