Sub-picosecond photoinduced hole and electron transfer of water-soluble graphitic carbon nitride in the presence of tryptophan and methyl viologen dichloride

Abstract

The electron and hole extraction kinetics are fundamental processes in graphitic carbon nitride related materials and play important roles in their applications. Herein, we designed two systems, water soluble graphitic carbon nitride (WSGCN) with tryptophan (Trp) and methyl viologen dichloride (MV2+), respectively, and recorded the formation and disappearance kinetics of Trp+· and MV+· after excitation of WSGCN by using femtosecond transient absorption spectroscopy to study the sub-picosecond hole transfer process from photoexcited WSGCN to Trp and the sub-picosecond electron transfer process from photoexcited WSGCN to MV2+. We determined that the hole transfer time constant from photoexcited WSGCN to Trp is 200 ± 20 fs and that the electron transfer time constant from photoexcited WSGCN to MV2+ is 110 ± 20 fs, both of which are consistent with the predictions of classical Marcus electron transfer theory.