Li_1.3Al_0.3Ti_1.7(PO₄)₃ (LATP), one of the NASICON-type solid-state electrolytes, possesses a high ionic conductivity, excellent chemical stability, and high shear modulus (40-60 GPa). However, the tetravalent titanium ion in LATP is particularly prone to undergo reduction reaction with lithium metal during cycling, leading to the structure degradation and electron introduction in LATP electrolyte. In order to maintain the chemical and electrochemical stability of LATP, this work modified the surface of LATP solid electrolyte with a Prussian blue (PB) interfacial layer to optimize the contact between electrolyte and anode. Using PB with abundant open-frame lithium ion diffusion channels as the mixed conductive modification layer has several advantages. (1) Intrinsic conductivity of PB layer is enhanced after lithiation, accelerating homogenized transmission of electrons from the interfacial layer to the negative electrode. (2) Lithiation process is accompanied by enhancing lithium affinity of PB intermediate layer, which enables the interface contact between LATP and lithium metal to be closer during the electrochemical process. (3) Lithiated PB still maintains a three-dimensional skeleton structure, which is conducive to the homogenization effect of lithium ion flux at interface, thereby promoting stabilization of lithium deposition/stripping process. (4) The PB with metal-organic framework (MOF) structure is conducive to ensuring the mechanical stability of interface during cycling and reducing volume change of lithium negative electrode. (5) The PB structure does not collapse after lithiation, not easy to cause phase separation and additional phase boundaries or phase gaps, which is conducive to the integration of lithium ion flow and electron flow. (6) More uniquely, redox potential of PB is higher than those of lithium metal and LATP on both sides of the PB interface, conducive to the formation of an electron transport barrier between Li and LATP, and prevents the reduction and degradation of LATP. The improved solid-state battery has good cycling stability and kinetic performance. At a current density of 0.025 mA·cm^-2, the PB-modified Li/Li symmetric solid-state cell can achieve a stable cycle of 800 h. After 160 cycles at a current density of 0.025 mA·cm^-2, the capacity of PB-modified Li/LiFePO₄ solid-state battery is still close to 200 mAh·g^-1. The modified Li/FeF₃ solid-state battery can be operated at 0.025 mA·cm^-2 with the preservation of a high Coulombic efficiency, indicating that the PB modification has good tolerance to the volume change generated during electrochemical cycling.

Thermoelectric materials are functional materials that can realize the direct conversion between heat and electricity, which have great prospects in the field of green refrigeration and waste heat recovery. To date, researches on thermoelectric materials mainly focus on semiconducting inorganic materials and conductive polymers. Although great progress has been made regarding material design and performance improvement, it is still of great significance to explore and expand thermoelectric candidates for potential application. Metal-organic frameworks (MOFs) are porous extended solids formed by coordination bonds between organic ligands and metal ions or metal clusters. They are promising candidates in the field of thermoelectrics due to their unique porous structure as well as tunable composition and structure, which could meet the requirement of "electron crystal-phonon glass". In this work, conductive polymer, poly(3, 4-vinyl dioxythiophene) (PEDOT) was in-situ polymerized in Zr-based MOFs UiO-67 through “conductive guest-promoted transport” approach. The confined effects originated from porous structures of MOFs on molecular chains of PEDOT effectively improve electrical conductivity of the composites. As a result, the prepared composites exhibit an electrical conductivity up to 5.96×10⁻³ S·cm⁻¹ at room temperature, which is one order of magnitude higher than the corresponding PEDOT. Correspondingly, their power factor (PF) is up to 3.67×10⁻² nW·m⁻¹·K⁻² at room temperature. In conclusion, this work uses ordered porous structures of MOFs as reaction platform and constructs conductive polymer/MOFs conductive materials by facile in-situ polymerization methods, providing a reference for further development of MOFs-based thermoelectric materials.

Cu/Mg-MOF-74 has several advantages, such as high specific surface area, adjustable microporous structure, alkali metal active site, excellent CO₂ adsorption, and good photocatalytic activity. However, how the molar ratio of Cu/Mg (Cu/Mg ratio) affects its CO₂ adsorption selectivity in a simulated flue gas is still unclear. Here, a synthesized Cu/Mg-MOF-74, with series of Cu/Mg ratios, using the solvothermal method was analyzed about its CO₂ photocatalytic performance, CO₂ and N₂ uptake, and pore structure. The CO₂ adsorption selectivity was calculated to reveal the effect of Cu/Mg ratio on CO₂ and N₂ uptake and selectivity. The results indicate that the photocatalytic activity of Cu/Mg-MOF-74 for CO₂ reduction to CO and H₂ initially increases and then decreases with Cu/Mg ratio decreasing. At the Cu/Mg ratio of 0.6/0.4, the yield of CO and H₂ by photocatalytic reduction is the highest, showing up to 10.65 and 5.41 μmol·h⁻¹·g_cat⁻¹ (1 MPa, 150 ℃), respectively. Furthermore, CO₂ and N₂ uptakes of Cu/Mg-MOF-74 increase as the Cu/Mg ratio decreases, and the increase in CO₂ uptake is more pronounced. At the Cu/Mg ratio of 0.1/0.9, the CO₂ and N₂ uptakes are the largest, reaching 9.21 and 1.49 mmol·g⁻¹ (273.15 K, 100 kPa), respectively. Their area and volume of micropore (d₁ ≥ 0.7 nm) and ultramicropore (d₂ < 0.7 nm) increase as the Cu/Mg ratio decreases. At the Cu/Mg ratio of 0.22/0.78, the area and volume of micropores and ultramicropores are larger than those of Mg-MOF-74. The selectivity of Cu/Mg-MOF-74 increases correspondingly with Cu/Mg ratio decreasing and CO₂ concentration increasing. CO₂ adsorption on Cu/Mg-MOF-74 is a combination process of pore-filling and Mg²⁺ chemical adsorption in which the micropore volume is the key factor affecting its adsorption performance. All above data demonstrate that modulating the Cu/Mg ratio can promisingly regulate the pore structure of Cu/Mg-MOF-74, CO₂ uptake, and selectivity.

The all-inorganic CsPbX₃ (X=Cl, Br, I) perovskite nanocrystals have been widely applied in optoelectronic devices due to their excellent optoelectronic properties. However, their poor stability remains one of the main factors restricting their commercial development. This research focuses on improving the stability and solid-state luminescence performance of CsPbBr₃ nanocrystals. The porous MIL-53 (Al) metal-organic frameworks (MOFs) with outstanding hydrophobic properties was chosen as the encapsulation matrix. CsPbBr₃ nanocrystals were grown in situ within the MIL-53 (Al) channels by using a thermal injection process to successfully synthesize CsPbBr₃@MIL-53 nanocomposite phosphors with outstanding solid-state luminescence performance and high stability. MIL-53 chelates with CsPbBr₃ nanocrystals through benzene rings and organic ligands, firmly anchoring nanocrystals in the pores. This not only protects the CsPbBr₃ nanocrystals from external environmental influences but also effectively prevents aggregation between nanocrystals, thereby avoiding quenching of solid-state fluorescence. Additionally, the COO^- functional groups in MIL-53 bind with the unpaired Pb²⁺ on the surface of CsPbBr₃ nanocrystals, passivating the surface defects and suppressing non-radiative carrier recombination. Furthermore, the contained benzene rings and organic long chains endow the nanocomposite phosphors with excellent hydrophobic properties. The synergistic effect of these factors significantly enhances the optical performance and water stability of CsPbBr₃@MIL-53 nanocomposite phosphors. As a result, photoluminescence quantum yield (PLQY) of CsPbBr₃@MIL-53 nanocomposite phosphors reaches 75.4%, which is 2.3 times of that of solid-state CsPbBr₃ nanocrystal powders (33.2%). Even after being completely immersed in water for 10 h, its fluorescence intensity can still maintain 75.6% of the initial value. Finally, the green-emitting CsPbBr₃@MIL-53 nanocomposite phosphors were applied to white LED devices, achieving a wide-color-gamut coverage area of 126% NTSC and 85% Rec. 2020, which demonstrates its application prospects in wide-color-gamut display devices.

Volatile organic compounds (VOCs) pose significant risks to environmental quality and human health. To enhance adsorption performance of adsorbents for VOCs, further improvement of the unsaturated metal centers becomes a key factor based on the principle that metal ions can be replaced in metal organic frameworks (MOFs). Here, a one-step solvothermal synthesis system was utilized to dope abundant, cost-effective, and environment friendly Al³⁺ ions into MIL-101(Cr) for preparing Al-MIL-101(Cr). Morphologies and structures of MIL-101(Cr) and Al-MIL-101(Cr) samples, alongside the static adsorption performance for toluene, n-hexane, oil and p-xylene, were analyzed. Static adsorption capacities of toluene, n-hexane, oil, and p-xylene of MIL-101(Cr) were 0.676, 0.621, 0.451 and 0.812 g·g^-1, respectively. When Al³⁺ doping amount reached 0.75 mmol, Al-0.75-MIL-101(Cr) displayed maximum VOCs adsorption capacities (0.911 g·g^-1 for toluene, 0.755 g·g^-1 for n-hexane, 0.713 g·g^-1 for oil, and 0.875 g·g^-1 for p-xylene). The dynamic toluene adsorption behavior was assessed through single-component breakthrough curves. Both dynamic and static adsorption results demonstrate that Al-MIL-101(Cr) possesses excellent VOCs removal capabilities, which are attributed to the extensive specific surface area and augmented unsaturated metal sites.