Ag@g-C₃N₄/MoS₂ heterostructure for efficient photocatalytic oxygen evolution under visible light irradiation

Area of Science:

• Materials Science
• Photocatalysis
• Renewable Energy

Background:

• Solar-to-water oxidation is crucial for clean energy production.
• Developing efficient photocatalysts remains a key challenge.
• Graphitic carbon nitride (g-C3N4) and Molybdenum disulfide (MoS2) show promise but require optimization.

Purpose of the Study:

• To synthesize and characterize a novel Ag@g-C3N4/MoS2 heterostructure.
• To evaluate its efficiency for solar-to-water oxidation.
• To elucidate the underlying photocatalytic mechanism.

Main Methods:

• Synthesis of Ag@g-C3N4/MoS2 heterostructure.
• UV-visible diffuse reflectance spectroscopy (UV-vis DRS) for band gap analysis.
• Steady-state photoluminescence (PL) spectroscopy for charge separation evaluation.
• Oxygen evolution rate measurements under solar irradiation.

Main Results:

• The Ag@g-C3N4/MoS2 heterostructure was successfully synthesized.
• UV-vis DRS revealed a narrow band gap of 2.10 eV.
• PL analysis indicated efficient charge separation facilitated by Ag nanoparticles and MoS2.
• Oxygen production rate increased approximately 3.2-fold (2727 μmol g-1 h-1) compared to Ag@g-C3N4.

Conclusions:

• The Ag@g-C3N4/MoS2 heterostructure is a highly efficient photocatalyst for solar-to-water oxidation.
• The enhanced performance is attributed to the narrow band gap and improved charge carrier dynamics.
• A Z-scheme mechanism is proposed to explain the efficient photocatalytic activity.