Developing an efficient NiCo₂S₄ cocatalyst for improving the visible light H₂ evolution performance of CdS...

Area of Science:

• Materials Science
• Photocatalysis
• Renewable Energy

Background:

• Platinum (Pt) is the standard cocatalyst for photocatalytic water splitting but is expensive.
• Efficient and affordable alternatives are needed for large-scale hydrogen energy production.
• Cadmium sulfide (CdS) is a semiconductor used in photocatalysis but requires cocatalysts for enhanced performance.

Purpose of the Study:

• To synthesize nickel cobalt sulfide (NiCo2S4) as a novel, cost-effective cocatalyst.
• To investigate the use of NiCo2S4 with CdS for visible light-driven hydrogen generation.
• To evaluate the photocatalytic activity and understand the mechanism of the NiCo2S4/CdS composite.

Main Methods:

• Facile synthesis of NiCo2S4 and NiCo2S4/CdS composite materials.
• Comprehensive material characterization using XRD, SEM, TEM, EDX, XPS, DRS, and N2 adsorption.
• Photocatalytic hydrogen generation rate measurement under visible light irradiation.
• Photoelectrochemical measurements including PL spectroscopy, transient photocurrent response, and EIS.

Main Results:

• The NiCo2S4/CdS composite demonstrated a high H2 generation rate of 137 μmol h−1, over 17 times greater than bare CdS.
• Characterization confirmed the successful synthesis and structure of the NiCo2S4/CdS heterostructure.
• Enhanced charge carrier migration and separation were observed in the composite, attributed to the heterostructure.

Conclusions:

• NiCo2S4 is a highly active and cost-affordable cocatalyst for visible light photocatalytic H2 generation.
• The NiCo2S4/CdS composite significantly enhances photocatalytic performance due to improved charge carrier dynamics.
• This work presents a promising strategy for efficient and economical hydrogen production via photocatalysis.