NiSe₂/Twinned-MnCdS Dual-Junction for Enhanced Photocatalytic Hydrogen Performance

Area of Science:

• Materials Science
• Photocatalysis
• Nanotechnology

Background:

• Efficient charge separation and migration are critical for advancing semiconductor photocatalysis.
• Developing novel materials with enhanced charge dynamics is essential for improving photocatalytic efficiency.

Purpose of the Study:

• To synthesize a twinned MnCdS homojunction (T-MCS) coupled with NiSe2 to create a homo-heterojunction system.
• To investigate the synergistic effects of internal twin boundaries and heterojunction coupling on charge separation and photocatalytic performance.
• To optimize the NiSe2 loading on T-MCS for maximum hydrogen production.

Main Methods:

• Hydrothermal synthesis of twinned MnCdS homojunction (T-MCS).
• Oil-bath method for coupling T-MCS with NiSe2.
• Photocatalytic hydrogen production rate measurements.
• Density Functional Theory (DFT) calculations and experimental analysis.

Main Results:

• The optimized 5 wt% NiSe2/T-MCS achieved a hydrogen production rate of 5.17 mmol g⁻¹ h⁻¹.
• This rate is 3.9 times higher than pristine T-MCS and 10.5 times higher than pure WZ-MCS.
• DFT calculations and experiments confirmed that synergistic interactions create internal electric fields, facilitating charge migration and suppressing recombination.

Conclusions:

• The developed NiSe2/T-MCS homo-heterojunction system exhibits superior photocatalytic performance.
• Integrating twinned structure engineering with dual-junction approaches offers a promising strategy for designing efficient photocatalysts.
• This work provides insights into manipulating charge dynamics for enhanced photocatalysis.