Role of nitrogen and silver compounds in photocatalytic properties of carbon nanoparticle

To develop the photocatalytic method of water decontamination in an industrial scale, the structure of the photocatalyst should be modified in order to work under visible light irradiation. This paper is a report on a comparison of the efficiency of the photocatalytic activity of carbon, carbon nitride (CN) and carbon-silver (CAg) nanostructures for the degradation of Methylthioninium chloride in water. Carbon nanoparticles were synthesized by pulsed laser ablation (PLA) of a graphite target in distilled water. To synthesize CN nanocomposite, carbon nanoparticles were placed in normal pressure nitrogen-filled oven at 700 °C for 5 h. And to synthesize the CAg nanocomposite, bulk silver was ablated in the carbon nanoparticles solution by pulsed laser. Degradation was examined in dark condition and under the UV and visible light irradiations. Results show that the efficiency of photocatalytic activity of carbon dots as an abundant nanomaterial was increased, by their modification through atomic substitution (carbon nitride) and alloying (carbon-silver). Results show that the chemical properties of CN made this nanocomposite have the best performance among the 3 nanomaterials in dark and UV irradiated conditions, while the plasmonic absorption of silver nanoparticles made this material to have the best photocatalytic performance under visible light irradiation.