Polyoxometalate-Induced Interfacial Charge Transfer in g-C₃N₄ toward Visible-Light Photocatalysis

Area of Science:

• Materials Science
• Photocatalysis
• Nanotechnology

Background:

• Photocatalytic efficiency relies on interfacial charge dynamics.
• Graphitic carbon nitride (g-C₃N₄) is a promising photocatalyst but suffers from charge recombination.
• Polyoxometalates (POMs) can act as electron acceptors.

Purpose of the Study:

• To investigate the role of polyoxometalate (POM), specifically H₃PMo₁₂O₄₀·xH₂O (PMo₁₂), as an interfacial electron acceptor.
• To construct and characterize PMo₁₂@g-C₃N₄ composites for enhanced photocatalysis.
• To elucidate the interfacial electronic interactions and charge-transfer mechanisms in these composites.

Main Methods:

• Synthesis of PMo₁₂@g-C₃N₄ composites with varying PMo₁₂ content.
• Characterization of composite materials to understand structural and electronic properties.
• Evaluation of photocatalytic hydrogen evolution rates under visible light irradiation.

Main Results:

• The optimized 5 wt % PMo₁₂@g-C₃N₄ composite showed significantly enhanced visible-light-driven hydrogen evolution.
• A hydrogen evolution rate of 3.38 mmol g^-1 h^-1 was achieved, representing a 2.56-fold increase over pristine g-C₃N₄.
• Enhanced interfacial charge separation and transfer dynamics were confirmed in the composites.

Conclusions:

• Polyoxometalate (POM) acts as an effective interfacial electron acceptor when coupled with g-C₃N₄.
• The PMo₁₂@g-C₃N₄ composite strategy successfully improves photocatalytic activity.
• This work provides insights into designing semiconductor-cluster hybrid photocatalysts for efficient solar energy conversion.