One-Pot Fabrication of Perforated Graphitic Carbon Nitride Nanosheets Decorated with Copper Oxide by Controlled Ammonia and Sulfur Trioxide Release for Enhanced Catalytic Activity.

In this article, we have judiciously interfaced copper oxides with graphitic carbon nitride (g-CN) from thermal reaction of melamine and copper sulfate in a one-pot protocol and manipulated the perforated sheet morphology thereafter. The CCN- ( = 30, 40, 50, 60, and 70, depending on the wt % of CuSO·5HO) nanocomposites were prepared by homogenously mixing different percentages of CuSO·5HO with melamine from a solid-state thermal reaction in a furnace in air. Drastic lowering of CuSO decomposition temperature due to Cu(II)-amine complex formation and subsequent reduction of Cu(II) species by in situ produced ammonia (NH) resulted in the production of CuO and catalytic amount of CuO, homogeneously dispersed within the perforated g-CN nanosheet. How perforated sheet morphology evolved by combined effect of NH, released from thermal condensation of melamine ensuring two-dimensional (2D) growth, and sulfur trioxide (SO), expelled from CuSO·5HO facilitating the perforation, yielding better catalytic performance, has been elucidated. Excess NH from added NHCl removed perforation and ensued a marked decrease in efficacy. However, a high proportion of CuSO·5HO ruptured the framework of 2D sheets because of excess SO evolution. Among the different nanocomposites synthesized, CCN-40 (CuO-CuO/g-CN) showed the highest catalytic activity for 4-nitrophenol reduction. Thus, enhanced efficiency of the copper oxide catalyst by interfacing it with an otherwise inactive g-CN platform was achieved.