Graphene dot-embedded porous WO3 photoanode for highly efficient photoelectrochemical water splitting

The development of semiconductor photoanodes with improved photoelectrochemical (PEC) efficiency and stability for the purpose of realizing solar water splitting is a crucial challenge that carries substantial practical implications. In this study, GQDs/WO3 composite porous photoanodes were fabricated using a pulsed anodization method in an aqueous electrolyte containing hydroxyl GQDs. The morphology and crystal structure of the as-prepared GQDs/WO3 porous films were characterized by SEM, TEM, XRD, XPS, Raman spectra, and FTIR. The successful embedding of GQDs into the WO3 walls to form tightly bound heterojunctions was confirmed. It was investigated how the GQD content influenced the photoelectrochemical properties of the GQDs/WO3 heterojunctions. The optimal photocurrent densities observed in the GQDs/WO3 samples (10-WO3) were found to be three times higher compared to those obtained from pure WO3 porous films. This significant enhancement clearly indicates the positive impact of GQDs on the PEC performance. The boosted PEC activity of the GQDs/WO3 heterojunction photoanode was attributed to the fact that the introduction of GQDs promotes more efficient light absorption, charge separation, and transport processes within the heterojunction structure. Moreover, the GQDs/WO3 composites photoelectrodes exhibited excellent PEC stability, predicting its enormous potential for practical applications.

Automated summary

In this study, GQDs/WO3 composite porous photoanodes were fabricated using a pulsed anodization method, showing significant enhancement in photoelectrochemical performance and excellent PEC stability. This research is of great importance for the realization of solar water splitting.