  Water dissociation is of fundamental importance in scientific fields and has
drawn considerable interest in diverse technological applications. However, the
high activation barrier of breaking the O-H bond within the water molecule has
been identified as the bottleneck, even for the water adsorbed on the graphene
oxide (GO). Herein, using the density functional theory calculations, we
demonstrate that the water molecule can be spontaneously dissociated on GO
supported by the (111) surface of the copper substrate (Copper-GO). This
process involves a proton transferring from water to the interfacial oxygen
group, and a hydroxide covalently bonding to GO. Compared to that on GO, the
water dissociation barrier on Copper-GO is significantly decreased to be less
than or comparable to thermal fluctuations. This is ascribed to the
orbital-hybridizing interaction between copper substrate and GO, which enhances
the reaction activity of interfacial oxygen groups along the basal plane of GO
for water dissociation. Our work provides a novel strategy to access water
dissociation via the substrate-enhanced reaction activity of interfacial oxygen
groups on GO and indicates that the substrate can serve as an essential key to
tuning the catalytic performance of various two-dimensional material devices.
