Strain-induced ultrahigh power conversion efficiency in BP-MoSe₂vdW heterostructure

Area of Science:

• Materials Science
• Photocatalysis
• Hydrogen Production

Background:

• Photocatalytic water splitting is a key technology for sustainable hydrogen fuel production.
• Two-dimensional van der Waals (vdW) heterostructures are emerging as promising candidates for efficient photocatalysts.
• Developing novel materials with enhanced performance is crucial for advancing this field.

Purpose of the Study:

• To investigate the potential of a blue phosphorus-MoSe2 (BP-MoSe2) vdW heterostructure as a photocatalyst for water splitting.
• To evaluate the electronic band structure, optical properties, and catalytic activity of the proposed heterostructure.
• To determine the influence of strain on the photocatalytic performance.

Main Methods:

• First-principles calculations were employed to model and analyze the BP-MoSe2 vdW heterostructure.
• The electronic band structure, band edge positions, and optical absorption spectra were computed.
• Gibbs free energy profiles were calculated to assess catalytic activity for hydrogen and oxygen evolution.

Main Results:

• The BP-MoSe2 heterostructure exhibits a type-II band structure, with band edges aligning with water redox potentials under biaxial strain (-3% to 2%).
• The material demonstrates strong optical absorption across visible and near-ultraviolet light, with a power conversion efficiency (PCE) reaching ~20.2% under 2% tensile strain.
• Calculated Gibbs free energy profiles indicate good catalytic performance for both hydrogen and oxygen evolution reactions.

Conclusions:

• The BP-MoSe2 vdW heterostructure is a highly promising material for photocatalytic water splitting, offering efficient charge separation and transport.
• Strain engineering can significantly enhance the power conversion efficiency and overall performance of the heterostructure.
• The material's properties suggest its potential for practical applications in clean hydrogen production.