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Mitigating ambient nitrogen dioxide (NO2 ) pollution via selective adsorption on porous materials is a promising approach to tackle such an increasingly pressing environmental health issue. However, very few porous adsorbents have sufficiently high NO2 adsorption capacity and good regenerability simultaneously. Here we attempt to address this challenge by developing π-backbonding adsorbents in the transition metal (TM) incorporated porphyrin metal-organic frameworks (PMOFs). Breakthrough experiments show that PMOFs with inserted TMs achieve appreciable NO2 capacity and good regenerability. Combined in situ DRIFTS, synchrotron powder XRD, and DFT calculations reveal the adsorption mechanism: NO2 partially transforms to N2 O4 and interacts with transition metal via π-backbonding and Al-node via hydrogen bonding. This work affords new insights for designing next-generation adsorbents for ambient NO2 removal and presents PMOFs as a platform to tailor π-backbonding adsorbents.

On the road to find complementary candidates to the present commercial lithium ion batteries, electrode materials with high performance for both sodium ion batteries and potassium ion batteries are attracting more and more attention. Herein, hierarchical hollow CoP and carbon composites were obtained through a facile synthetic method, where carbonization and phosphorization of the precursor were completed within one single step. The composites are composed of hollow CoP@C spheres, which are further made up of CoP nanoparticles with a thin outer carbon layer. Electrochemical performances of the prepared CoP@C composites as anodes for sodium and potassium storage were evaluated and compared. In-situ TEM, in-situ synchrotron XRD and density functional theory calculation were conducted to study the structural evolution and the interaction between Na/K and CoP during cycling processes. Benefiting from the synergistic effect of conductive carbon layer and hierarchical hollow structure, the as-prepared CoP@C composites demonstrate superior sodium and potassium storage capability as anode materials for rechargeable batteries.

Homochiral metal-organic frameworks (MOFs) have gained much attention because of their chiral properties and disposition for chiral separation. However, the fabrication of high-quality homochiral MOF membranes remains challenging because of the difficulty in controlling growth of MOF membranes with chiral functionalities. A homochiral zeolitic imidazolate framework-8 (ZIF-8) membrane is reported for efficient chiral separation. The membrane is synthesized by incorporating a natural amino acid, l-histidine (l-His), into the framework of ZIF-8. The homochiral l-His-ZIF-8 membrane exhibits a good selectivity for the R-enantiomer of 1-phenylethanol over the S-enantiomer, showing a high enantiomeric excess value up to 76 %.