Highly Efficient Photocatalytic Degradation of Dyes by a Copper-Triazolate Metal-Organic Framework

A copper(I) 3,5-diphenyltriazolate metal-organic framework (CuTz-1) was synthesized and extensively characterized by using a multi-technique approach. The combined results provided solid evidence that CuTz-1 features an unprecedented Cu₅ tz₆ cluster as the secondary building unit (SBU) with channels approximately 8.3 Å in diameter. This metal-organic framework (MOF) material, which is both thermally and chemically (basic and acidic) stable, exhibited semiconductivity and high photocatalytic activity towards the degradation of dyes in the presence of H₂ O₂ . Its catalytic performance was superior to that of reported MOFs and comparable to some composites, which has been attributed to its high efficiency in generating ^. OH, the most active species for the degradation of dyes. It is suggested that the photogenerated holes are trapped by Cu^I , which yields Cu^II , the latter of which behaves as a catalyst for a Fenton-like reaction to produce an excess amount of ^. OH in addition to that formed through the scavenging of photogenerated electrons by H₂ O₂ . Furthermore, it was shown that a dye mixture (methyl orange, methyl blue, methylene blue, and rhodamine B) could be totally decolorized by using CuTz-1 as a photocatalyst in the presence of H₂ O₂ under the irradiation of a Xe lamp or natural sunlight.