Triphenylamine-functionalized graphene decorated with Pt nanoparticles and its application in photocatalytic hydrogen production

A new type of graphene-based nanohybrid was prepared from graphene nanosheets and 4-(diphenylamino)benzaldehyde (TPA-CHO) through 1,3-dipolar cycloaddition. The nanohybrid was modified by platinum nanoparticles via photodeposition. The nanohybrid and its Pt modified nanocomposite were characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Ultraviolet–visible absorption (UV–vis), Fourier transform infrared (FTIR), and Raman spectra confirmed that triphenylamine moiety grafted on the graphene surface. The results of fluorescence quenching and photocurrent enhancement of the triphenylamine-functionalized graphene revealed that photoinduced electron transfer from triphenylamine moiety to the graphene sheet. The investigation of using the Pt modified graphene-based nanocomposite as a photocatalyst for H₂ evolution showed that under UV–vis light irradiation, the average H₂ evolution rate and the quantum efficiency is 2.3 μmol h⁻¹ and 0.45% mol E⁻¹, respectively. This work demonstrated a potential application of an organic sensitizer covalently functionalized graphene as a novel photocatalyst in the field of solar energy conversion.