Metal-organic frameworks (MOFs) have demonstrated great potentials in a variety of important applications. To enhance the inherent properties and endow materials with multifunctionality, the rational design and synthesis of MOFs with nanoscale porosity and hollow feature is highly desired and remains a great challenge. In this work, the formation of a series of well-defined MOF (MOF-5, Fe(II) -MOF-5, Fe(III) -MOF-5) hollow nanocages by a facile solvothermal method, without any additional supporting template is reported. A surface-energy-driven mechanism may be responsible for the formation of hollow nanocages. The addition of pre-synthesized poly(vinylpyrrolidone)- (PVP) capped noble-metal nanoparticles into the synthetic system of MOF hollow nanocages yields the yolk-shell noble metal@MOF nanostructures. The present strategy to fabricate hollow and yolk-shell nanostructures is expected to open up exciting opportunities for developing a novel class of inorganic-organic hybrid functional nanomaterials.

A one-pot method was developed to prepare atomic thick nanosheets of metastable TiO(2)(B), which has a unique open structure owing to the coupling of intrinsic channels and the preferentially exposed (010) facets. They display high activity of doping due to the rapid incorporation and diffusion along these open channels.

Supports can widely affect or even dominate the catalytic activity, selectivity, and stability of metal nanoparticles through various metal-support interactions (MSIs). However, underlying principles have not been fully understood yet, because MSIs are influenced by the composition, size, and facet of both metals and supports. Using Ru/TiO2 supported on rutile and anatase as model catalysts, we demonstrate that metal-support interfacial compatibility can critically control MSI modes and catalytic performances in CO2 hydrogenation. Annealing Ru/rutile-TiO2 in air can enhance CO2 conversion to methane resulting from enhanced interfacial coupling driven by matched lattices of RuOx with rutile-TiO2; annealing Ru/anatase-TiO2 in air decreases CO2 conversion and converts the product into CO owing to strong metal-support interaction (SMSI). Although rutile and anatase share the same chemical composition, we show that interfacial compatibility can basically modify metal-support coupling strength, catalyst morphology, surface atomic configuration, MSI mode, and catalytic performances of Ru/TiO2 in heterogeneous catalysis.

Highly selective macromembranes, fabricated by cation-decorated graphene oxide, exhibit an excellent selectivity toward a wide range of solvents. Mixed solvents are successfully separated, based on which a membrane reactor is designed to promote a series of chemical reactions. The cations bonding to the graphene oxide nanosheets are found to be responsible for this selectivity by cation-π, electrostatic interactions, and hydrogen bonding.

A novel strategy for the versatile functionalization of the external surface of metal-organic frameworks (MOFs) has been developed based on the direct coordination of the phenolic-inspired lipid molecule DPGG (1,2-dipalmitoyl-sn-glycero-3-galloyl) with metal nodes/sites surrounding the MOF external surface. XRD and Argon (Ar) sorption analysis prove that the modified MOF particles retain their structural integrity and porosity after surface modification. Density functional theory (DFT) calculations reveal that strong chelation strength between the metal sites and the galloyl head group of DPGG is the basic prerequisite for successful surface coating. Due to the pH-responsive nature of metal-phenol complexation, the modification process is reversible by simple washing in weak acidic water, showing an excellent regeneration ability for water-stable MOFs. Moreover, the colloidal stability of the modified MOF particles in the nonpolar toluene solvent allows them to be further organized into 2D MOF or MOF/polymer monolayers by evaporation-induced interfacial assembly conducted on an air/water interface. Finally, the easy fusion of a second functional layer onto DPGGmodified MOF cores, enabled a series of MOF-based functional nanoarchitectures, such as MOFs encapsulated within hybrid supported lipid bilayers (so-called protocells), polyhedral core-shell structures, hybrid lipid-modified-plasmonic vesicles and multicomponent supraparticles with target functionalities, to be generated for a wide range of applications.