Linear control of the oxidation level on graphene oxide sheets using the cyclic atomic layer reduction technique

Area of Science:

• Materials Science
• Nanotechnology
• Surface Chemistry

Background:

• Controlling the oxidation level of graphene oxide (GO) is crucial for its applications.
• Conventional reduction methods offer limited, stepwise control over GO's oxidation state.

Purpose of the Study:

• To demonstrate a linear control of surface oxidation on GO sheets.
• To explore the tunability of optical and electronic properties via controlled reduction.

Main Methods:

• Utilized an atomic layer reduction (ALR) technique at 100 °C and 150 °C.
• Assessed the oxygen stripping rate during ALR cycling at different temperatures.
• Employed ALR/atomic layer oxidation (ALO) cycles for in situ oxidation control.

Main Results:

• Achieved linear control of the surface oxidation level on GO sheets.
• Determined oxygen stripping rates of 0.055% per cycle (150 °C) and 0.028% per cycle (100 °C).
• Demonstrated linear tuning of optical band gap and electrical conductivity with ALR cycles.

Conclusions:

• The ALR technique provides unprecedented linear control over GO oxidation.
• ALR/ALO cycles offer reversible tuning of chemical composition and properties.
• This method overcomes limitations of conventional stepwise reduction techniques.