A Urea Precursor to Synthesize Carbon Nitride with Mesoporosity for Enhanced Activity in the Photocatalytic Removal of Phenol

Abstract A urea precursor was used for the first time to prepare mesoporous carbon nitride (MCN) by a thermal polymerization process with silica nanospheres as a hard template. Although the prepared MCN samples have similar structures and optical properties, it was revealed that the specific surface area, pore‐size distribution, and morphology of the MCN samples depend on the initial mass ratio of urea to silica. Compared to the bulk carbon nitride (BCN) that only gave 20 % phenol removal (6 h of irradiation), the activities can be enhanced up to 74 % on MCN samples for photocatalytic removal of phenol under visible‐light irradiation. The highest conversion was obtained on MCN with an initial mass ratio of urea to silica of 5, which has high surface area of 191 m 2 g −1 and a nanoporous structure with uniform pore‐size distribution of 7 nm. In addition to the high activity, the MCN sample also showed high photocatalytic stability.