Water splitting kinetics of Sr-doped g-C3N4 edge-wrinkled nanosheets under visible light

Abstract

For achieving superior photoelectrochemical water splitting activity, semiconductor material should prevail high absorption capacity, suppressed charge carrier recombination, and high electrical conductivity. The graphitic carbon nitride (g-C3N4) unable to demonstrate significant water splitting activity because it cannot reach the above requirements. In such a way, we adopted the doping concept to enhance the physical, chemical, and water splitting activity of the g-C3N4 nanostructure. Therefore, the controllability of Sr incorporation into g-C3N4 leads to the enhanced water splitting activity, which was attributed to the evolution in the structural, morphological, and optical properties. In addition, the spectroscopy analysis was distinctively used to reveal the incorporation of Sr2+ into the g-C3N4 host lattice. The impedance analysis demonstrated the promising charge carrier kinetics under strategic Sn doping. The gentle doping of Sr (0.4 mol%) into g-C3N4 exhibited considerable improvement in the photocurrent generation, which is ~82 times higher than that of pristine g-C3N4. In a word, the improved photoelectrochemical performance can be ascribed to the synergistic effects of extended light absorption, enhanced charge carrier generation, separation, transportation, and development of additional active sites.