Tetrafluoroborate

Catalysis

Composite number

Engineering

Boron

Materials science

Boron nitride

Carbon fibers

Inorganic chemistry

Chemical engineering

Band gap

Porosity

Hydrogen

Nanotechnology

Organic chemistry

Doping

Carbon nitride

Graphitic carbon nitride

Composite material

Ionic bonding

Chemistry

Ionic liquid

Photocatalysis

Hydrogen production

Optoelectronics

Chemosphere

This work presents a simple way to prepare boron-doped graphitic carbon nitride (B/g-C3N4), exhibiting an enhanced photocatalytic performance to split water for hydrogen production. B/g-C3N4 was synthesized via the pyrolysis of urea and 1-ethyl-3-methylimidazolium tetrafluoroborate ([Emim]BF4), which was adopted as the boron source. The aggregate of B/g-C3N4 nanosheets shows a porous structure since some bubbles are generated under the heat decomposition of ionic liquids. The porous structure is conducive to the exposure of more active sites. Moreover, B-doping will form some localized electronic energy levels in the band gap of g-C3N4, thereby extending its visible light response. As impacted by the porous structure of B/g-C3N4 aggregate and the narrow the band gap, the photocatalytic hydrogen generation rate (901 μmol h-1 g-1) is increased, almost 3 times faster than g-C3N4 (309 μmol h-1 g-1). This work proposed a simple method to prepare the aggregate of B/g-C3N4 nanosheets exhibiting pores under ionic liquid assistance. It can be a novel method to design porous polymer photocatalysts.

Ionic liquid-assisted synthesis of porous boron-doped graphitic carbon nitride for photocatalytic hydrogen production