Highly enhanced photocatalytic property dominantly owing to the synergic effects of much negative Ecb and S-scheme heterojunctions in composite g-C3N4/Mo-doped WO3

In this work, an S-scheme heterojunction-structured composite, g-C 3 N 4 /Mo-doped WO 3 (mass ratio 100:5, labeled 5M15WOCN) together with pure WO 3 , g-C 3 N 4 , and Mo-doped WO 3 (labeled M15WO) was prepared. The as-prepared samples were characterized by XRD , UV–Vis DRS, SEM, TEM, ESR , EIS , PL and XPS . The photocatalytic properties were investigated by photodegrading methyl orange (MO). The following findings were obtained. The dopant Mo increased the amount of O v -s and produced W 5+ , along with prolonging the lifetime of photogenerated carriers, improving the transfer ability of carriers. The S-scheme heterojunction g-C 3 N 4 /M15WO drastically improved the photocatalytic properties, dominantly due to the synergetic effect of the O v -s, S-scheme mechanism and very negative CB potential. A new phenomenon is found in which W 6+ can combine with the net electrons coming from the side with a higher Fermi level in the heterojunction and form W 5+ , suggesting a good method for stabilizing the high valence state for the material by combining one with a lower Fermi level. This work also implies that, compared to the S-scheme, a more negative CB is much more beneficial for MO photodegradation .