Water stable tetranuclear copper(I) iodide cluster for visible-light driven photocatalytic application

Organic pollutions in wastewater are very harmful to environment and human health; their effective removal is important but still challenging. Copper iodine (CuI) is a promising semiconductor photocdatalyst, but still faces obvious drawbacks, e.g., only absorbing the UV light and serious electron-hole recombination. Herein, we report an effective hybrid copper(I) iodine-based photocatalyst [Cu4I4(EBT)5] (UJN Cu, EBT = 3-ethyl-1,3-benzothiazole-2-thione), which represents the first tetranuclear copper(I) iodine cluster been used for visible-light driven photocatalytic application. Importantly, the photocatalytic rate constant of UJN-Cu toward degrading organic dye pollution is three times larger than that for nitrogen-doped TiO2, and can retain similar activity after at least four runs. The holes are the dominated active species of photocatalyst UJN-Cu in such photocatalytic system. This work not only provides one promising copper(I) iodine-based semiconductor photocatalyst, but also unveils the feasibilities of tetranuclear copper(I) iodine cluster for wastewater purification.