Microwave-assisted chemical modification of g-C3N4 for photoinduced processes: organic degradation, hydrogen production and selective oxidation of alcohols

Abstract

g-C3N4 powders were treated by means of the microwave technique in three different aqueous and organic media (HNO3, NaOH and N,N-dimethylformamide). All powders were analyzed by XRD reveling that g-C3N4 maintains its structure. The morphology of the samples was analyzed with scanning electron microscopy, where the micrographs reveals that the modifcation occurs on the surface of the g-C3N4. The photocatalytic activity of the samples was evaluated in the degradation of ciprofoxacin, hydrogen production and for the selective partial oxidation of 4-methoxybenzylalcohol (4-MBA) to its aldehyde. The sample treated with HNO3 (C3N4-HNO3) shows the best photocatalytic performance in the degradation of ciprofoxacin achieving a degradation around 57%. On the other hand, sample treated with N,N-dimethylformamide (C3N4-DMF) presents the highest hydrogen production (283 µmol H2 g−1 h−1). In the last process, samples C3N4-HNO3 and C3N4-DMF show an 80% of selectivity in the conversion of 4-MBA.