Reducing agent-free formation of Cu(I) nanoclusters on gC3N4 for enhanced photocatalysis

Copper species with +1 oxidization state, CuI), in amorphous form can potentially be employed for photocatalytic activity improvement due to its ability to capture photoproduced hole. However, this proposition has never been confirmed experimentally, likely due to difficulty in forming such amorphous CuI) on the host photocatalyst surface. In the present work, CuI) amorphous nanoclusters are successfully deposited on the gC(3)N(4) surface via ultrasonication without any external reducing agent for enhancement of visible light photocatalytic activity. Since Cu species are introduced in low concentrations and cannot be satisfactorily inspected using conventional characterization techniques, synchrotronbased techniques including XANES, EXAFS and soft-XAS are therefore used for interrogating the oxidation state and local structure of CuI) nanoclusters as well as the structural features of gC(3)N(4). Appreciable enhancement of photocatalytic activity of CuI)/gC(3)N(4) is shown for degradation and mineralization of atrazine under visible light. The CuI)/gC(3)N(4) also exhibits relatively high adsorption capability for atrazine, which is up to 37% of total atrazine removal. These obtained results are very encouraging and may find applications in abatement of other recalcitrant organic contaminants combining adsorption and photocatalysis. (C) 2017 Elsevier B.V. All rights reserved.