Uracil Derivative-Assisted Universal Synthesis of Defective 2-Dimensional Porous Flaky Carbon Nitride for Efficient Photocatalytic Co2 Reduction

Abstract

In this paper, three novel carbon nitrides with two-dimensional porous nanosheets were successfully synthesized by supramolecular method using melamine, cyanuric acid and uracil derivatives (5-formyluracil, 5-acetyluracil, uracil-5-carboxylic acid) as ligands for photocatalytic reduction of CO2. This method induced abundant oxygen and nitrogen defects upon carbon nitrides, which was supported by various characterizations. These defects can effectively modulate the electronic structure of carbon nitrides, thus enhancing the separation ability of photogenerated charge carriers. Compared with bulk carbon nitride, the synthesized material shows significantly enhanced photocatalytic activity under mild conditions. More importantly, with the support of in-situ DRIFTS, we proposed the reaction mechanisms of photocatalytic reduction of CO2.

Keywords: supramolecular, 2-dimensional lamellar C3N4, oxygen defect, nitrogen vacancy, CO2 reduction