We review progress in the study of electroactive MOFs with redox activity for energy conversion and storage. Recent advances in mixed-valence MOFs are highlighted, which have led to record conductivities towards metallic porous materials.

Two-dimensional electrically conductive metal-organic frameworks (MOFs) have emerged as promising model electrodes for use in electric double-layer capacitors (EDLCs). However, a number of fundamental questions about the behaviour of this...

An interfacial engineering approach was adopted in order to optimize the photovoltaic parameters and the stability of n-i-p planar perovskite solar cells (PSCs). A thin manganese (Mn) porphyrin [(TMePyP)I 4 Mn(AcO)] layer was introduced between the titania (TiO 2 ) electron transport layer (ETL) and the perovskite absorber. The introduction of porphyrin onto the TiO 2 substrate provoked a significant decrease in the work function (W F ), which arose from the large local dipole moment. The modification also provided a more hydrophobic environment that favored the growth of homogeneous and large perovskite crystals. Moreover, the electron charge transport to the ETL was facilitated via the highly paramagnetic character of the Mn porphyrin, whereas the negative impact of humidity and oxygen on the PSC performance was hindered. Density functional theory analysis justified the observed large decrease of the W F and the strong electronic coupling of porphyrin with the TiO 2 compact layer (following the porphyrin deposition), which are beneficial for electron extraction. By combining the Mn porphyrin and the CH 3 NH 3 PbI 3 perovskite, significant enhancement of the stabilized power conversion efficiency by 22% was recorded. The shelf-shield stability was also improved after more than 600 h of storage in the dark under ambient conditions.

Symmetry breaking in covalent organic frameworks (COFs) lowers the energy and increases the valence to conduction band separation of the material.

Electroconductive metal–organic frameworks (MOFs) have emerged as high-performance electrode materials for supercapacitors, but the fundamental understanding of the underlying chemical processes is limited. Here, the electrochemical interface of Cu3(HHTP)2 (HHTP = 2,3,6,7,10,11-hexahydroxytriphenylene) with an organic electrolyte is investigated using a multiscale quantum-mechanics/molecular-mechanics (QM/MM) procedure and experimental electrochemical measurements. Our simulations reproduce the observed capacitance values and reveals the polarization phenomena of the nanoporous framework. We find that excess charges mainly form on the organic ligand, and cation-dominated charging mechanisms give rise to greater capacitance. The spatially confined electric double-layer structure is further manipulated by changing the ligand from HHTP to HITP (HITP = 2,3,6,7,10,11-hexaiminotriphenylene). This minimal change to the electrode framework not only increases the capacitance but also increases the self-diffusion coefficients of in-pore electrolytes. The performance of MOF-based supercapacitors can be systematically controlled by modifying the ligating group.