Mechanically Induced Highly Efficient Hydrogen Evolution from Water over Piezoelectric SnSe nanosheets

Area of Science:

• Materials Science
• Catalysis
• Nanotechnology

Background:

• Piezoelectric nanomaterials can drive green catalysis by harvesting mechanical energy.
• Current piezoelectric catalysts have limited efficiency for processes like hydrogen evolution.
• Two-dimensional tin selenide (SnSe) shows potential due to predicted high piezoelectricity, charge mobility, and flexibility.

Purpose of the Study:

• To investigate few-layer piezoelectric SnSe nanosheets for mechanically induced hydrogen evolution from water.
• To evaluate the piezoelectric performance and catalytic efficiency of SnSe nanosheets.

Main Methods:

• Finite element method simulations to predict piezoelectric potential.
• Fabrication and characterization of few-layer SnSe nanosheets.
• Experimental measurement of piezocurrent density under ultrasonic excitation.
• Quantification of hydrogen production rate.

Main Results:

• Simulations predicted a maximal piezoelectric potential of 44.1 V for a single SnSe nanosheet.
• A record piezocurrent density of 0.3 mA cm⁻² was achieved, three orders of magnitude higher than reported piezocatalysts.
• An exceptional hydrogen production rate of 948.4 µmol g⁻¹ h⁻¹ was obtained without a cocatalyst.
• Performance is competitive with current photocatalysis technology.

Conclusions:

• Few-layer SnSe nanosheets are highly effective for piezocatalytic hydrogen evolution.
• SnSe demonstrates superior performance compared to existing piezocatalysts.
• This work provides a promising material and strategy for efficient, mechanically driven hydrogen production.