Simultaneously tuning interlayer spacing and termination of MXenes by Lewis-basic halides

Area of Science:

• Materials Science
• Nanotechnology
• Electrochemistry

Background:

• Surface and interface chemistry are critical for controlling the properties of two-dimensional transition metal carbides and nitrides (MXenes).
• While Ti3C2Tx MXene has been extensively studied, tuning interlayer spacing and surface termination of other MXenes remains a significant challenge.
• Developing versatile methods to modify diverse MXene materials is highly desirable for expanding their applications.

Purpose of the Study:

• To introduce a new method for simultaneously engineering the interlayer spacing and surface termination of various MXenes.
• To demonstrate the effectiveness of Lewis-basic halides treatment for MXene modification.
• To explore the impact of this treatment on the electrochemical performance of MXenes.

Main Methods:

• Utilized a Lewis-basic halides treatment involving molten state Lewis-basic halides.
• Employed nucleophilic reactions to substitute fluorine termination on MXene surfaces.
• Investigated the changes in interlayer spacing and surface chemistry of treated MXenes.

Main Results:

• Successfully engineered both interlayer spacing and surface termination of various MXenes using Lewis-basic halides.
• Achieved substitution of -F termination and enlargement of interlayer spacing.
• Ti3C2Tx MXene treated with this method exhibited a specific capacity of 229 mAh g-1 for Li+ storage, nearly double that of the pristine material.

Conclusions:

• The Lewis-basic halides treatment offers a versatile approach for regulating MXene properties.
• This method allows for simultaneous control over interlayer spacing and surface termination across different MXene types.
• The enhanced properties, particularly in energy storage, suggest broad potential applications for treated MXenes in fields like energy storage and optoelectronics.