In order to develop efficient visible light driven photocatalysts for environmental applications, novel polymeric g-C₃N₄ layered materials with high surface areas are synthesized efficiently from an oxygen-containing precursor by directly treating urea in air between 450 and 600 °C, without the assistance of a template for the first time. The as-prepared g-C₃N₄ materials with strong visible light absorption have a band gap around 2.7 eV. The crystallinity and specific surface areas of g-C₃N₄ increases simultaneously when the heating temperatures increases. The g-C₃N₄ materials are demonstrated to exhibit much higher visible light photocatalytic activity than that of C-doped TiO₂ and g-C₃N₄ prepared from dicyanamide for the degradation of aqueous RhB. The large surface areas, layered structure and band structure in all contributed to the efficient visible light photocatalytic activity. The efficient synthesis method for g-C₃N₄ combined with efficient photocatalytic activity is of significant interest for environmental pollutants degradation and solar energy conversion in large scale applications.

Polymeric nitrogen-rich graphitic carbon nitride (g-C₃N₄-T) nanocatalyst was synthesized for the first time with a facile approach by directly treating low cost thiourea in air. The g-C₃N₄-T demonstrated much higher visible light photocatalytic activity than that of g-C₃N₄ obtained from toxic dicyandiamide, C-doped TiO₂ and P25.