  Improving interfacial thermal transport is crucial for heat dissipation in
systems. Here, we design a strategy by utilizing the water
adsorption-desorption process in porous metal-organic frameworks (MOFs) to tune
the interfacial heat transfer. We observe a changeable thermal conductance
across the solid/porous MOFs interfaces owing to the dense water channel formed
by the adsorbed water molecules in MOFs. Our experimental results show that the
interfacial thermal conductance of Au/Cu3(BTC)2 heterointerfaces is increased
up to 7.1 folds by this strategy, where Cu3(BTC)2 is a typical porous MOF and
usually referred to as HKUST-1. Our molecular dynamics simulations further show
that the surface tension of Au layer will cause the adsorbed water molecules in
HKUST-1 to gather at the interfacial region. The dense water channel formed at
the interfacial region can activate the high-frequency lattice vibrations and
act as an additional thermal pathway, and then enhance heat transfer across the
interfaces significantly. Our findings provide a new concept for tailoring
thermal transport at the solid/porous MOFs heterointerfaces which will largely
benefit MOF-related applications.
