Gold nanochannels oxidation by confined water

Area of Science:

• Surface Science
• Nanotechnology
• Physical Chemistry

Background:

• Confined water plays a crucial role in various processes, but its behavior, especially chemical reactivity, remains poorly understood.
• Simulations suggested hydrophilic behavior of the first water layer on gold surfaces, contrasting with bulk water's hydrophobicity.

Purpose of the Study:

• Investigate the properties of confined water specifically on gold (Au) 〈111〉 nanochannels.
• Examine the hydrophilicity of the first water layer and explore any unique reactions occurring within these nanochannels.

Main Methods:

• Utilized a comprehensive approach combining morphological, structural, and spectroscopic experimental data.
• Employed *ab initio* computer simulations to analyze water behavior and surface interactions.

Main Results:

• Experimental and computational findings strongly support the hydrophilicity of the first water layer on Au 〈111〉.
• Observed a unique oxidation process within the nanochannels, leading to the formation of gold(III) hydroxide (Au(OH)₃).

Conclusions:

• The hydrophilicity of the first water layer on Au 〈111〉 surfaces is confirmed.
• The reactivity of gold surfaces with confined water, including oxidation, must be considered for nanoscopic applications.
• Findings are relevant for catalysis in fine chemicals, pharmaceuticals, and green processes in the food industry.