Molten salts synthesis and visible light photocatalytic activity of crystalline poly(triazine imide) with different morphologies

Graphite-phase carbon nitride (g-C3N4) has a unique semiconductor band structure (band gap width 2.7 eV), excellent chemical stability and non-toxicity, which has potential application in the field of environmental pollution treatment and energy conversion. However, low specific surface area and high recombination photo-generated electrons–holes, which lead to low quantum efficiency of photocatalytic process and seriously restrict its photocatalytic activity. Herein, crystalline poly(triazine imide) (PTI) with different morphologies was synthesized by molten salts method. The results showed that the layer structure, hollow tubes and nanosheets of crystalline PTI were obtained according to different mass ratio of raw materials and molten salt. The degradation of rhodamine B under visible light irradiation was used to evaluate the catalytic activity of the photocatalyst. The PTI nanosheets exhibited highest visible light catalytic activity due to the increase in specific surface area and improvement of separation efficiency of electron hole pairs. A possible mechanism was also raised according to the results of trapping experimental and spectroscopic properties.