Charge Transfer Mechanism in Type II WO₃/Cu₂O Heterostructure

Area of Science:

• Materials Science
• Electrochemistry
• Photochemistry

Background:

• Tungsten trioxide (WO3) and copper(I) oxide (Cu2O) are semiconductor materials with potential applications in photoelectrochemical devices.
• Understanding charge transfer mechanisms is essential for optimizing the efficiency of these devices.

Purpose of the Study:

• To investigate the charge transfer mechanism between WO3 and Cu2O in heterostructured electrodes and tandem photoelectrochemical cells.
• To determine the predominant charge transfer pathway in WO3/Cu2O systems.

Main Methods:

• Fabrication of individual WO3 and Cu2O electrodes.
• Construction of heterostructured WO3/Cu2O electrodes and WO3||Cu2O tandem photoelectrochemical cells.
• Physical-chemical characterization using X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), and Scanning Electron Microscopy (SEM).
• Photoelectrochemical performance studies.

Main Results:

• Successful synthesis and characterization of WO3, Cu2O, and WO3/Cu2O heterostructures confirmed by XRD, XPS, and SEM.
• Photoelectrochemical studies indicated efficient charge transfer between WO3 and Cu2O.
• The primary charge transfer mechanism identified in both heterostructured electrodes and tandem cells is the Z-scheme.

Conclusions:

• The Z-scheme mechanism is the dominant charge transfer pathway in WO3/Cu2O heterostructures and tandem photoelectrochemical cells.
• This understanding provides a basis for designing more efficient photoelectrochemical systems utilizing WO3 and Cu2O.