Enhanced carriers separation efficiency in g-C3N4 modified with sulfonic groups for efficient photocatalytic Cr(VI) reduction

Rapid carrier transport and high carrier separation efficiency are key factors in improving photocatalytic performance. Herein, a novel sulfonic groups modified g-C3N4 photocatalyst was constructed by solution impregnation and evaporation method. The strong electronegativity of the sulfonic acid group provides a guide for the migration of electrons to the surface, thereby promoting the transport and separation of photogenerated carriers. In addition to that, the sulfonic acid group can also achieve spatial separation of carriers on the surface and serve as an active site. Based on the above merits, the sulfonic-acid-modified g-C3N4 exhibited a significantly enhanced visible light reduction Cr(VI) activity which is 2.9 times higher than that of pure g-C3N4.The resent work provides a new strategy for the surface modification of photocatalysts, which contributes to construct high performance photocatalysts.