Observations of the 22×√3 reconstruction of Au(111) under aqueous solutions using scanning tunneling microscopy

We have studied the Au(111) surface under potential control under water, 0.1 M HClO₄ and 10 mM NaH₂PO₄ using scanning tunneling microscopy. The 22×√3 reconstruction was observed, demonstrating that the reconstruction is stable in contact with aqueous solutions. The measured periodicity and z corrugation of the reconstruction are in good agreement with studies done in ultrahigh vacuum. The stability of the reconstruction was found to depend on surface potential (vs a silver quasi-reference electrode). We have also observed structures other than the 22×√3 pattern.