Graphene-Metal-Metastructure Monolith via Laser Shock-Induced Thermochemical Stitching of MOF Crystals

The hybrids of porous graphene and metal nanoparticles (MNPs) in a monolithic form are widely explored in energy and environmental sciences in which uniform dispersion of stable MNPs across the graphene backbone are required. However, it remains challenging to fabricate such a composite in a scalable and straightforward manner. Here, we demonstrate the direct laser conversion of metal-organic framework (MOF) crystals to a monolithic porous graphene with exceptional dispersion of MNPs in air. The strong interaction between laser pulses and MOF crystals created extremely localized high temperature and pressure (>2,200 K, >0.3 GPa), and subsequent removal of laser irradiation led to fast cooling and pressure release that generated monolithic structure. By rational choice of MOF precursors, the particle sizes of MNPs were systematically tuned. Because of efficient light trap in the monolith, exceptional high solar absorptivity above 99% was realized, which guaranteed high solar-thermal conversion efficiency of 94% in solar-driven desalination.