Light‐responsive adsorbents capture significant attention due to their tailorable performance upon light irradiation. The modulation of such adsorbents is mainly based on weak (physical) interactions caused by steric hindrance while tuning strong interaction with target adsorbates is scarce. Here we report smart π‐complexation adsorbents, which can adjust the π‐complexation of active sites via light irradiation. A typical metal‐organic framework, MIL‐101‐NH2, was decorated with azobenzene motifs, and Cu+ as π‐complexation active sites were introduced subsequently. The reversible light‐induced isomerization of azobenzene regulates the surface electrostatic potentials around Cu+ from −0.038 to 0.008 eV, causing shielding and exposure effects. The alteration of CO uptake is achieved up to 54 % via changing light, while that on MIL‐101‐NH2 is negligible. This study provides a clue for designing target‐specific smart materials to meet the practical stimuli‐responsive adsorption demands.

To date, some attempts have been made to synthesize hierarchically porous metal−organic frameworks (HPMOFs), and in most cases, mesopores are formed in microporous frameworks. However, mass transfer and diffusion are still limited in such HPMOFs since micropores connect mesopores and mesopores are noncontinuous. Here, we fabricate a new hierarchical structure through the formation of microporous MOFs within continuous mesoporous channels. Confined space in the as-prepared mesoporous silica-containing template was used to prepare well-dispersed metal precursor of ZnO. The strategy of ligand vapor-induced crystallization was then designed to construct MOFs inside mesoporous channels, in which vapored ligand at elevated temperature diffuses and reacts with metal precursor. Our results indicate that framework isomerism is controllable by adjusting the crystallization conditions. In comparison to their microporous and mesoporous counterparts, the hierarchically porous materials show obviously enhanced adsorption performance on a series of bulky molecules including dye, enzyme, and metal−organic polyhedron.

Light-responsive adsorbents capture significant attention due to their tailorable performance upon light irradiation. The modulation of such adsorbents is mainly based on weak (physical) interactions caused by steric hindrance while tuning strong interaction with target adsorbates is scarce. Here we report smart πcomplexation adsorbents, which can adjust the π-complexation of active sites via light irradiation. A typical metal-organic framework, MIL-101-NH 2 , was decorated with azobenzene motifs, and Cu + as π-complexation active sites were introduced subsequently. The reversible light-induced isomerization of azobenzene regulates the surface electrostatic potentials around Cu + from À 0.038 to 0.008 eV, causing shielding and exposure effects. The alteration of CO uptake is achieved up to 54 % via changing light, while that on MIL-101-NH 2 is negligible. This study provides a clue for designing target-specific smart materials to meet the practical stimuli-responsive adsorption demands.