High specific surface area defective g-C3N4 nanosheets with enhanced photocatalytic activity prepared by using glyoxylic acid mediated melamine

A new precursor was developed for the preparation of graphitic carbon nitride (g-C3N4) with a large specific surface area and N vacancies. The SEM and TEM results show that the obtained samples have porous nanosheet structure, XPS, EPR and UV–Vis spectra indicate N vacancy defects existed in the g-C3N4. During the synthesis process, glyoxylic acid inhibited the condensation of melamine, thus increasing the porosity of g-C3N4, generating abundant defects, and improving yield. Under light irradiation, g-C3N4 samples prepared by glyoxylic acid mediated melamine shown enhanced photocatalytic activities in gaseous organic pollution photodegradation. This study developed a potential agent for producing inexpensive and highly active g-C3N4 photocatalysts. The large specific surface area porous g-C3N4 sheets with nitrogen vacancies have been fabricated successfully by using a glyoxylic acid treated melamine. This method is a high-yield and low-cost synthetic pathway to form large specific surface area porous g-C3N4 nanosheet. The photocatalytic activity of g-C3N4 was enhanced in gaseous pollution photodegradation. [Display omitted] •Glyoxylic acid results in harvesting specific surface area, and generating defects in g-C3N4 simultaneously.•Glyoxylic acid reduces the cost of g-C3N4 greatly by increase the yield.•Enhanced activities in gaseous iso-propanol photodegradation and photoelectric properties.