Vibrational spectra of water at water/α-quartz (0 0 0 1) interface

Selected beam geometry allows us to suppress the bulk contribution to sum-frequency generation from crystalline quartz and use sum-frequency vibrational spectroscopy to study water/α-quartz interfaces with different bulk pH values. The spectra are qualitatively similar to those of water/fused-quartz interfaces, but display an ice-like peak that resembles very closely that of a real ice surface, providing the first evidence to the belief that water molecules at a crystalline oxide surface form a more ordered hydrogen-bonding network.