Microplasma electrochemistry (MIPEC) methods for improving the photocatalytic performance of g-C3N4 in degradation of RhB

[Display omitted] •A MIPEC method was developed for the post-functionalization of g-C3N4.•MIPEC method provided a combination of electrochemistry and plasma chemistry.•The photocatalytic activity of g-C3N4 could be controllable increased or decreased.•Improved photocatalytic activity was due to the oxidation and protonation effect.•Decrease of photocatalytic activity was due to the reduction effect. A microplasma electrochemistry (MIPEC) method was developed for the post-functionalization of g-C3N4 at room temperature and atmospheric pressure without harsh condition. The MIPEC method could provide a novel reaction environment with the combination of electrochemistry and plasma chemistry. The photocatalytic performances of treated g-C3N4 for Rhodamine B (RhB) degradation were investigated under different conditions in the aqueous state. g-C3N4 treated by microplasma anode exhibited an improved photocatalytic activity due to the oxidation and protonation effect, while g-C3N4 treated by microplasma cathode presented a decrease of photocatalytic activity due to the reduction effect. Characterizations include XRD, FTIR, PC, EIS under the light, and UV–vis DRS indicated that the as-prepared materials with expected properties were acquired, suggesting that the MIPEC is an effective and controllable method for materials synthesis and modification.