Synthesis of C/g-C₃N₄ Using Polystyrene as a Carbon Source Obtained by Pickering Emulsion and Its Visible-Light Catalytic Activity

Graphitic carbon nitride (g-C₃N₄) can be used as a photocatalytic initiator and stabilizer in the process of Pickering emulsion polymerization for polystyrene/g-C₃N₄. After carbonization, highly catalytically active carbon (C)/g-C₃N₄ is obtained. The properties of the photocatalysts are characterized by Fourier transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, thermogravimetric analysis, ultraviolet-visible spectroscopy, and electrochemical analysis. The degradation of methylene blue is investigated to determine the activity of the photocatalyst. The results suggest that polystyrene nanospheres coated with g-C₃N₄ can be obtained when the volume ratio of the g-C₃N₄ aqueous dispersion and styrene is more than 40. The obtained polystyrene/g-C₃N₄ exhibits strong interaction of matter causing by Pickering emulsion polymerization using g-C₃N₄ as the photocatalytic initiators and stabilizer. The interaction still exists in C/g-C₃N₄ when the polystyrene is carbonized, which can enhance the separation efficiency of photoelectron–hole pairs, reduce the charge transfer resistance, and accelerate the degradation of methylene blue. It is worth noting that the photocurrent density of C/g-C₃N₄ is about 68.3 times that of the original g-C₃N₄.