A Dual-Ligand Porous Coordination Polymer Chemiresistor with Modulated Conductivity and Porosity

Single-ligand-based electronically conductive porous coordination polymers/metal–organic frameworks (EC-PCPs/MOFs) fail to meet the requirements of numerous electronic applications owing to their limited tunability in terms of both conductivity and topology. In this study, a new 2D π-conjugated EC-MOF containing copper units with mixed trigonal ligands was developed: Cu₃(HHTP)(THQ) (HHTP=2,3,6,7,10,11-hexahydrotriphenylene, THQ=tetrahydroxy-1,4-quinone). The modulated conductivity (σ≈2.53×10⁻⁵ S cm⁻¹ with an activation energy of 0.30 eV) and high porosity (ca. 441.2 m² g⁻¹) of the Cu₃(HHTP)(THQ) semiconductive nanowires provided an appropriate resistance baseline and highly accessible areas for the development of an excellent chemiresistive gas sensor.     

Large-Scale Synthesis of MOF-Derived Superporous Carbon Aerogels with Extraordinary Adsorption Capacity for Organic Solvents

Carbon aerogels (CAs) with 3D interconnected networks hold promise for application in areas such as pollutant treatment, energy storage, and electrocatalysis. In spite of this, it remains challenging to synthesize high-performance CAs on a large scale in a simple and sustainable manner. We report an eco-friendly method for the scalable synthesis of ultralight and superporous CAs by using cheap and widely available agarose (AG) biomass as the carbon precursor. Zeolitic imidazolate framework-8 (ZIF-8) with high porosity is introduced into the AG aerogels to increase the specific surface area and enable heteroatom doping. After pyrolysis under inert atmosphere, the ZIF-8/AG-derived nitrogen-doped CAs show a highly interconnected porous mazelike structure with a low density of 24 mg cm⁻³, a high specific surface area of 516 m² g⁻¹, and a large pore volume of 0.58 cm⁻³ g⁻¹. The resulting CAs exhibit significant potential for application in the adsorption of organic pollutants.     

Hierarchically Ordered Porous Carbon with Atomically Dispersed FeN4 for Ultraefficient Oxygen Reduction Reaction in Proton-Exchange Membrane Fuel Cells

The low catalytic activity and poor mass transport capacity of platinum group metal free (PGM-free) catalysts seriously restrict the application of proton-exchange membrane fuel cells (PEMFCs). Catalysts derived from Fe-doped ZIF-8 could in theory be as active as Pt/C thanks to the high intrinsic activity of FeN₄; however, the micropores fail to meet rapid mass transfer. Herein, an ordered hierarchical porous structure is introduced into Fe-doped ZIF-8 single crystals, which were subsequently carbonized to obtain an FeN₄-doped hierarchical ordered porous carbon (FeN₄/HOPC) skeleton. The optimal catalyst FeN₄/HOPC-c-1000 shows excellent performance with a half-wave potential of 0.80 V in 0.5 m H₂SO₄ solution, only 20 mV lower than that of commercial Pt/C (0.82 V). In a real PEMFC, FeN₄/HOPC-c-1000 exhibits significantly enhanced current density and power density relative to FeN₄/C, which does not have an optimized pore structure, implying an efficient utilization of the active sites and enhanced mass transfer to promote the oxygen reduction reaction (ORR).     

Facile Synthesis of Hierarchical Nanosized Single-Crystal Aluminophosphate Molecular Sieves from Highly Homogeneous and Concentrated Precursors

The synthesis of hierarchical nanosized zeolite materials without growth modifiers and mesoporogens remains a substantial challenge. Herein, we report a general synthetic approach to produce hierarchical nanosized single-crystal aluminophosphate molecular sieves by preparing highly homogeneous and concentrated precursors and heating at elevated temperatures. Accordingly, aluminophosphate zeotypes of LTA (8-rings), AEL (10-rings), AFI (12-rings), and -CLO (20-rings) topologies, ranging from small to extra-large pores, were synthesized. These materials show exceptional properties, including small crystallites (30–150 nm), good monodispersity, abundant mesopores, and excellent thermal stability. A time-dependent study revealed a non-classical crystallization pathway by particle attachment. This work opens a new avenue for the development of hierarchical nanosized zeolite materials and understanding their crystallization mechanism.     

Mesoporous Carbon@Titanium Nitride Hollow Spheres as an Efficient SeS2 Host for Advanced Li–SeS2 Batteries

The introduction of a certain proportion of selenium into sulfur‐based cathodes is an effective strategy for enhancing the integrated battery performance. However, similar to sulfur, selenium sulfide cathodes suffer from poor cycling stability owing to the dissolution of reaction intermediate products. In this study, to exploit the advantages of SeS₂ to the full and avoid its shortcomings, we designed and synthesized a hollow mesoporous carbon@titanium nitride (HMC@TiN) host for loading 70 wt % of SeS₂ as a cathode material for Li–SeS₂ batteries. Benefiting from both physical and chemical entrapment by hollow mesoporous carbon and TiN, the HMC@TiN/SeS₂ cathode manifests high utilization of the active material and excellent cycling stability. Moreover, it exhibits promising areal capacity (up to 4 mAh cm⁻²) with stable cell performance in the high‐mass‐loading electrode.