Nanoscale lamination effect by nitrogen-deficient polymeric carbon nitride growth on polyhedral SrTiO3 for photocatalytic overall water splitting: Synergy mechanism of internal electrical field modulation

The light penetration effect will weaken the driving force of charge separation from phase to surface by the built-in electric field of nanoscale photocatalysts, like low-dimensional materials. Therefore, in this study, a novel nanoscale lamination catalyst design method was proposed using a polymeric carbon nitride (PCN)-nano polyhedral SrTiO3 core-shell structure catalyst (PCN-SrTiO3). The results showed that the nanoscale lamination effect could be generated by the formation of the N–Sr bond, which could regulate the built-in electric field of the PCN simultaneously. Moreover, detailed characterization indicated that the N–Sr bond, which facilitates the generation of N vacancies in PCN, could act as a novel channel for charge transfer. Both surface and interior core N-deficient PCN have been discovered, resulting in more positive and negative VB positions, respectively. Synchronously, the light absorption ability of the PCN-SrTiO3 samples increased. Consequently, the enhanced photocatalytic overall water splitting could be ascribed to the synergism of the built-in electric field regulation caused by the N-Sr formation-induced nanoscale lamination effect, which was favorable for energy flow adaption on the spatiotemporal scale.