G-C3N4/La2O3 nanocomposite as a photo-electrocatalyst in solar water splitting

Abstract

The enhancement of g-C3N4 photocatalytic performance is most effectively achieved through doping or composite incorporation. Notably, rare-earth element nanocomposites, characterized by their exclusive 4f electronic configuration, have demonstrated remarkable potential in boosting photocurrent density. In this study, we successfully prepared a Lanthanum (La)-incorporated g-C3N4 composite using the methanolic dispersion method, resulting in a photostable photoanode. The optimized g-C3N4 composite, featuring approximately ∼59.8 % La composition, exhibited a substantial photocurrent of approximately ∼10.16 μA cm−2, a significant improvement compared to the unaltered g-C3N4, which only achieved about 4.56 μA cm−2 at 1.23 vs. Ag/AgCl. The introduction of lanthanum into the composite modified the elemental composition by introducing oxygen-doping into the g-C3N4 structure. Additionally, the unique dual nanostructures, comprising nanoparticles and nanoflakes, played a crucial role in enhancing catalytic sites, increasing surface area, and improving light absorption. According to the BET analysis, the N2 adsorption–desorption isotherms reveal that the SBET of g-C3N4/la2O3–59.8 % is approximately 74.84 m2 g−1, surpassing the surface area of pristine g-C3N4, which is approximately 65.32 m2 g−1. Moreover, the formation of the nanocomposite contributed to a reduction in the band gap from 2.82 eV (pure g-C3N4) to 2.74 eV (g-C3N4/La-59.8 %). In conclusion, due to its exceptional photostability and remarkable performance, the g-C3N4/La2O3 nanocomposite exhibits significant promise as a potential candidate in the field of photocatalysis, with prospective applications in Photoelectrochemical (PEC) solar water splitting.