TiO2-CeO2/g-C3N4 S-scheme heterostructure composite for enhanced photo-degradation and hydrogen evolution performance with combined experimental and DFT study

The g-C3N4/TiO2 nanocomposites (NCs) are fabricated by optimization of calcination and subsequent hydro-thermal technique decorated with CeO2 nanoparticles (NPs) to build the g-C3N4/TiO2-CeO2 hybrid NCs. The chemical and surface characterizations of structural, morphological, elemental composition, optical, photo-degradation, HER performance and the DFT computation has been efficiently analyzed. The g-C3N4/ TiO2-CeO2 composite photocatalysts (PCs) exhibit photocatalytic improved performance (similar to 97 %) for MB aqueous dye related to pristine g-C3N4 and g-C3N4/TiO2 composite PCs. The obtained k value of the g-C3N4/ TiO2/CeO2 heterostructure composite PCs has around 0.0262 min(-1) and 6.1, 2.6 and 1.5 times higher than to g-C3N4 (0.0043 min(-1)), g-C3N4/CeO2 (0.0099 min(-1)) and g-C3N4/TiO2 (0.0180 min(-1)) PCs respectively. Likewise, the synergistic probable S-scheme charge separation mechanism based on scavengers' tests and other values, which leads to effective separation of photo-excited (e(-)-h(+)) pairs, whereas high degradation and more H2O molecules have photo-reduction to H-2. The H-2 evolution reaction (HER) and the electrochemical impedance spectroscopy (EIS) of the as-obtained samples were explored via electrochemical study. This exertion recommends that the rational strategy and building of g-C3N4/TiO2-CeO2 nano-heterostructures were beneficial for developing visible-light-driven recyclable PCs for ecological refinement.

Automated summary

The g-C3N4/TiO2-CeO2 composite photocatalysts exhibit significantly improved photocatalytic performance, with a degradation efficiency of 97% for organic dyes, which is 6.1 to 2.6 times higher than traditional photocatalysts.