Formic acid assisted fabrication of Oxygen-doped Rod-like carbon nitride with improved photocatalytic hydrogen evolution

Rod-like carbon nitrides synthesized by calcinating supramolecular precursors prepared from acid (or alkali) and melamine have attracted great attention because they have large surface area and abundant accessible active sites. However, they are highly inefficient in separating charges, which limits their photocatalytic activity. Here, we prepared porous, rod-shaped carbon nitrides doped with oxygen by calcinating the precursors prepared from melamine and formic acid. The porous O-doped g-C3N4 nanorods have a large surface area of 81.4 m2 g-1. In particular, the oxygen doped into the catalyst enables it to have high efficiency in utilizing light in a range of 420-600 nm, and significantly improves its ability to separate photogenerated carriers. Under light irradiation (λ ≥ 420 nm), the prepared catalyst exhibits high photocatalytic activity with a hydrogen production rate of 12,766 μmol g-1h-1, which is 18.3 times that of pure carbon nitride. This research provides a novel way of preparing highly active non-metallic photocatalysts.