The aprotic Li-CO 2 battery is emerging as a promising energy storage technology with the capability of CO 2 fixation and conversion. However, its practical applications are still impeded by the large overpotential. Herein, the general synthesis of a series of ultrathin 2D Ru-M (M = Co, Ni, and Cu) nanosheets by a facile one-pot solvothermal method is reported. As a proofof-concept application, the representative RuCo nanosheets are used as the cathode catalysts for Li-CO 2 batteries, which demonstrate a low charge voltage of 3.74 V, a small overpotential of 0.94 V, and hence a high energy efficiency of 75%. Ex/in situ studies and density functional theory calculations reveal that the excellent catalytic performance of RuCo nanosheets originates from the enhanced adsorption toward Li and CO 2 during discharge as well as the elevated electron interaction with Li 2 CO 3 during charge by the in-plane RuCo alloy structure. This work indicates the feasibility of boosting the electrochemical performance of Li-CO 2 batteries by in-plane metal alloy sites of ultrathin 2D alloy nanomaterials.

Defect-enhanced selective ion transport within a generator made from an ionic liquid film supported by ZIF-8-based membranes enables high-performance moisture energy harvesting.

We convert a coordination network into a covalent solid, while maintaining the crystallinity and greatly enhancing the framework rigidity and redox-active and photochemical properties. Specifically, intensely light-absorbing push–pull functions are postsynthetically installed by reacting the electrophilic TCNE (tetracyanoethylene) guests and the electron-rich alkyne side arms on a microporous Zr–organic framework, generating black microporous crystallites with a band gap smaller than 1.0 eV. The reaction proceeds in the known [2 + 2] cycloaddition–retroelectrocyclization mechanism and extensively establishes conjugated (polyene) bridges across the linker molecules. The donor (4-methoxyphenyl) and acceptor (dicyanovinyl) couples of the polyene bridges also act as an efficient fluorescent quencher and can be selectively installed in a thin outer layer of the host crystallite to form a core–shell assembly for turn-on fluorescent sensing of small amine molecules in water solutions.

The useful yet underutilized backfolded design is invoked here for functionalizing porous solids with the versatile carbazole function. Specifically, we attach carbazole groups as backfolded side arms onto the backbone of a linear dicarboxyl linker molecule. The bulky carbazole side arms point away from the carboxyl links and do not disrupt the Zr-carboxyl framework formation; namely, the resultant MOF solid ZrL1 features the same net as that of the unfunctionalized dicarboxyl linker, also known as the PCN-111 net or UiO-66 net. The ZrL1 structure features only half linker occupancy (about 6 out of the 12 linkers around the Zr6O8 cluster being missing) and partially collapses upon activation (acetone exchange and evacuation). Notably, the stability improves after heating in diphenyl oxide at 260 °C (POP-260 treatment; to form ZrL1-260), as indicated by the higher crystallinity and surface area of the activated ZrL1-260 sample. The ZrL1-260 samples achieve 72% yield in photocatalyzing reductive dehalogenation of phenacyl bromide; ZrL1 can detect nitro-aromatic compounds via fluorescence quenching, with selectivity and sensitivity toward 4-nitroaniline, featuring a limit of detection of 96 ppb.

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