Simple method for preparing of sulfur-doped graphitic carbon nitride with superior activity in CO2 photoreduction

S-doped porous carbon nitride was obtained by a simple method using melamine and sulfuric acid. The synthesized material exhibits high BET specific surface area (75 m(2)/g) compared to non-doped C3N4 (25 m(2)/g). According to X-ray photoelectron spectroscopy sulfur atoms substitute nitrogen forming C-S bonds in the structure of carbon nitride. Incorporation of sulfur into C3N4 results in a significant increase of the light absorbance intensity especially in the UV region compared to undoped sample. Synthesized S-doped carbon nitride was found to be p-type semiconductor with high catalytic activity towards photoreduction of carbon dioxide with water vapour. Doping C3N4 with sulfur increases the catalytic activity in this reaction almost tenfold.