Engineering of HO-Zn-N Active Sites in Zeolitic Imidazolate Frameworks for Enhanced (Photo)Electrocatalytic Hydrogen Evolution.

Currently, lack of ways to engineer specific and well-defined active sites in zeolitic imidazolate frameworks (ZIFs) limits our fundamental knowledge with respect to the mechanistic details for (photo)electrocatalytic hydrogen evolution reaction (HER). Here, we introduce the open metal sites into ZIFs through the selective ligand removal (SeLiRe) strategy, comprehensively characterize the altered structural and electronic features, and evaluate their role in HER. In situ electrochemical analysis and X-ray absorption spectroscopy reveal the formation of high-valence HO-Zn-N sites through the binding of Zn-N with electrolyte hydroxide.

Ligand engineering enhances (photo) electrocatalytic activity and stability of zeolitic imidazolate frameworks via in-situ surface reconstruction.

The current limitations in utilizing metal-organic frameworks for (photo)electrochemical applications stem from their diminished electrochemical stability. In our study, we illustrate a method to bolster the activity and stability of (photo)electrocatalytically active metal-organic frameworks through ligand engineering. We synthesize four distinct mixed-ligand versions of zeolitic imidazolate framework-67, and conduct a comprehensive investigation into the structural evolution and self-reconstruction during electrocatalytic oxygen evolution reactions.

Polymerized ionic liquid Co-catalysts driving photocatalytic CO transformation.

Photocatalytic production of CO from CO has the potential for safe and atom-economic production of feedstock chemicals carbonylation chemistry. We developed novel ionic liquid-based polymeric materials through radical copolymerisation of 1-butyl-3-vinylimidazolium chloride and photocatalytically active Re- and Ru-complexes that serve as the CO reduction catalyst and photosensitiser, respectively. The crosslinked polymeric framework allows for the facile immobilisation of molecular organometallic complexes for use as heterogenised catalysts; moreover, the involved imidazolium core units co-catalyze the reduction of CO covalent interaction.

Harnessing a Ti-based MOF for selective adsorption and visible-light-driven water remediation.

In pursuit of universal access to clean water, photocatalytic water remediation using metal-organic frameworks (MOFs) emerges as a strong alternative to the current wastewater treatment methods. In this study, we explore a unique Ti-based MOF comprised of 2D secondary-building units (SBUs) connected biphenyl dicarboxylic acid (Hbpdc) ligands - denoted as COK-47 - as a visible-light-driven photocatalyst for organic dye degradation. Synthesized a recently developed microwave-assisted method, COK-47 exhibits high hydrolytic stability, demonstrates a strong dye uptake, and shows noteworthy dye-degradation performance under UV, visible, and solar light, outperforming benchmark TiO and MIL-125-Ti photocatalysts.

Case report: Predictability of clinical response and rejection risk after immune checkpoint inhibition in liver transplantation.

Background: The approval of Atezolizumab / Bevacizumab therapy (Atezo/Bev) in 2020 opened up a promising new treatment option for patients with end-stage hepatocellular carcinoma (HCC). However, liver transplant (LTx) patients with HCC are still denied this therapy owing to concerns about ICI-induced organ rejection and lack of regulatory approval.

Methods: A prospective observational study at a tertiary liver transplant centre monitored the compassionate, off-label use of Atezo/Bev in a single, stable LTx recipient with non-resectable HCC recurrence.

MOCHAs: An Emerging Class of Materials for Photocatalytic H Production.

Production of green hydrogen (H) is a sustainable process able to address the current energy crisis without contributing to long-term greenhouse gas emissions. Many Ag-based catalysts have shown promise for light-driven H generation, however, pure Ag-in its bulk or nanostructured forms-suffers from slow electron transfer kinetics and unfavorable Ag─H bond strength. It is demonstrated that the complexation of Ag with various chalcogenides can be used as a tool to optimize these parameters and reach improved photocatalytic performance.

A thiomolybdate cluster for visible-light-driven hydrogen evolution: comparison of homogeneous and heterogeneous approaches.

This study investigates the hydrogen evolution reaction (HER) efficiency of two photosystems incorporating an all-inorganic molecular thiomolybdate [MoS] cluster as a HER catalyst. First, we delve into the performance of a homogeneous [MoS]/[Ru(bpy)] (Mo/Ru) dyad which demonstrates high turnover frequencies (TOFs) and apparent quantum yields (AQYs) at 445 nm approaching the level of 0.5%, yet its performance is marked by pronounced deactivation.

Silicon Oxycarbide (SiOC)-Supported Ionic Liquids: Heterogeneous Catalysts for Cyclic Carbonate Formation.

Silicon oxycarbides (SiOCs) impregnated with tetrabutylammonium halides (TBAX) were investigated as an alternative to silica-based supported ionic liquid phases for the production of bio-based cyclic carbonates derived from limonene and linseed oil. The support materials and the supported ionic liquid phases (SILPs) were characterized via Fourier transform infrared spectroscopy, thermogravimetric analysis, nitrogen adsorption, X-ray photoelectron spectroscopy, microscopy, and solvent adsorption. The silicon oxycarbide supports were pyrolyzed at 300-900 °C prior to being coated with different tetrabutylammonium halides and further used as heterogeneous catalysts for the formation of cyclic carbonates in batch mode.

Hierarchically Micro- and Mesoporous Zeolitic Imidazolate Frameworks Through Selective Ligand Removal.

A new method to engineer hierarchically porous zeolitic imidazolate frameworks (ZIFs) through selective ligand removal (SeLiRe) is presented. This innovative approach involves crafting mixed-ligand ZIFs (ML-ZIFs) with varying proportions of 2-aminobenzimidazole (NH-bIm) and 2-methylimidazole (2-mIm), followed by controlled thermal treatments. This process creates a dual-pore system, incorporating both micropores and additional mesopores, suggesting selective cleavage of metal-ligand coordination bonds.

Thiomolybdate Clusters: From Homogeneous Catalysis to Heterogenization and Active Sites.

Thiomolybdates are molecular molybdenum-sulfide clusters formed from Mo centers and sulfur-based ligands. For decades, they have attracted the interest of synthetic chemists due to their unique structures and their relevance in biological systems, e.g.

Engineering g-CN with CuAl-layered double hydroxide in 2D/2D heterostructures for visible-light water splitting.

CuAl layered double hydroxide (LDH) and polymeric carbon nitride (g-CN, GCNN) were assembled to construct a set of novel 2D/2D CuAl-LDH/GCNN heterostructures. These materials were tested towards H and O generation from water splitting using visible-light irradiation. Compared to pristine materials, the heterostructures displayed strongly enhanced visible-light H evolution, dependent on the LDH content, which acts as a cocatalyst, replacing the benchmark Pt.

Microwave-assisted synthesis of metal-organic chalcogenolate assemblies as electrocatalysts for syngas production.

Today, many essential industrial processes depend on syngas. Due to a high energy demand and overall cost as well as a dependence on natural gas as its precursor, alternative routes to produce this valuable mixture of hydrogen and carbon monoxide are urgently needed. Electrochemical syngas production via two competing processes, namely carbon dioxide (CO) reduction and hydrogen (H) evolution, is a promising method.

Enhanced Oxygen Evolution Reaction Activity in Hematite Photoanodes: Effect of Sb-Li Co-Doping.

Co-doping represents a valid approach to maximize the performance of photocatalytic and photoelectrocatalytic semiconductors. Albeit theoretical predictions in hematite suggesting a bulk n-type doping and a surface p-type doping would deliver best results, hematite co-doping with coupled cations possessing low and high oxidation states has shown promising results. Herein, we report, for the first time, Sb and Li co-doping of hematite photoanodes.

Linear indium atom chains at graphene edges.

The presence of metal atoms at the edges of graphene nanoribbons (GNRs) opens new possibilities toward tailoring their physical properties. We present here formation and high-resolution characterization of indium (In) chains on the edges of graphene-supported GNRs. The GNRs are formed when adsorbed hydrocarbon contamination crystallizes via laser heating into small ribbon-like patches of a second graphitic layer on a continuous graphene monolayer and onto which In is subsequently physical vapor deposited.

Ni tetracubane cores with slow relaxation of magnetization and efficient charge utilization for photocatalytic hydrogen evolution.

We report two Ni multicubane topologies enclosed in the polyanions [Ni(OH)(WO)(PO)(B-α-PWO)]{NiW} and [Ni(OH)(HPO)(PO)(B-α-PWO)(A-α-PWO)]{NiW} that magnetically behave as Ni units clearly distinguishing them from typical Ni cubanes as shown by magnetic studies together with high field and frequency electron paramagnetic resonance (HFEPR). Beyond the unprecedented static properties, {NiW} shows the unusual coexistence of slow relaxation of the magnetization and a diamagnetic ground state ( = 0), providing the unique opportunity of studying the essentially elusive magnetic relaxation behavior in excited states. The cubane-topology dependent activity of {NiW} and {NiW} as homogeneous HER photocatalysts unveils the structural key features significant for the design of photocatalysts with efficient charge utilization exemplified by high quantum yields (QY) of 10.

Functionalization of decavanadate anion by coordination to cobalt(II): Binding to proteins, cytotoxicity, and water oxidation catalysis.

A series of five decavanadates (V) using a simple, one-pot synthesis, adhering to the model template: transition metal ion - decavanadate - ligands:(Hnicotinamide){[Co(HO)(nicotinamide)][μ-VO]}.6HO (1), {[Co(HO)(isonicotinamide)]}VO·4HO (2), {[Co(HO)][Co(HO)(μ-pyrazinamide)][μ-VO]}·4HO (3) {[Co(HO)(μ-pyrazinamide)].VO}·4HO (4), and (NH){[Ni(HO)(2-hydroxyethylpyridine)]}VO·2HO (5) was synthesized.

Continuous Formation of Limonene Carbonates in Supercritical Carbon Dioxide.

We present a continuous flow method for the conversion of bioderived limonene oxide and limonene dioxide to limonene carbonates using carbon dioxide in its supercritical state as a reagent and sole solvent. Various ammonium- and imidazolium-based ionic liquids were initially investigated in batch mode. For applying the best-performing and selective catalyst tetrabutylammonium chloride in continuous flow, the ionic liquid was physisorbed on mesoporous silica.

Recent advances in application of metal-organic frameworks (MOFs) as adsorbent and catalyst in removal of persistent organic pollutants (POPs).

The presence of persistent organic pollutants (POPs) in the aquatic environment is causing widespread concern due to their bioaccumulation, toxicity, and possible environmental risk. These contaminants are produced daily in large quantities and released into water bodies. Traditional wastewater treatment plants are ineffective at degrading these pollutants.

Immobilization of a [CoCo(HO)WO] Polyoxoanion for the Photocatalytic Oxygen Evolution Reaction.

The ongoing transition to renewable energy sources and the implementation of artificial photosynthetic setups call for an efficient and stable water oxidation catalyst (WOC). Here, we heterogenize a molecular all-inorganic [CoCo(HO)WO] ({CoCoW}) Keggin-type polyoxometalate (POM) onto a model TiO surface, employing a 3-aminopropyltriethoxysilane (APTES) linker to form a novel heterogeneous photosystem for light-driven water oxidation. The {CoCoW}-APTES-TiO hybrid is characterized using a set of spectroscopic and microscopic techniques to reveal the POM integrity and dispersion to elucidate the POM/APTES and APTES/TiO binding modes as well as to visualize the attachment of individual clusters.

Surface Anchoring and Active Sites of [MoS] Clusters as Co-Catalysts for Photocatalytic Hydrogen Evolution.

Achieving light-driven splitting of water with high efficiency remains a challenging task on the way to solar fuel exploration. In this work, to combine the advantages of heterogeneous and homogeneous photosystems, we covalently anchor noble-metal- and carbon-free thiomolybdate [MoS] clusters onto photoactive metal oxide supports to act as molecular co-catalysts for photocatalytic water splitting. We demonstrate that strong and surface-limited binding of the [MoS] to the oxide surfaces takes place.

All-Inorganic Perovskite Solar Cells with Tetrabutylammonium Acetate as the Buffer Layer between the SnO Electron Transport Film and CsPbI.

All-inorganic CsPbI perovskites have great potential in tandem cells in combination with other photovoltaic devices. However, CsPbI perovskite solar cells (PSCs) still face a huge challenge, resulting in a low power conversion efficiency (PCE) relative to organic-inorganic PSCs. In this work, we introduced tetrabutylammonium acetate (TBAAc) as a buffer layer between the SnO electron-transport layer (ETL) and CsPbI all-inorganic perovskite film interface for the first time.

Selective ligand removal to improve accessibility of active sites in hierarchical MOFs for heterogeneous photocatalysis.

Metal-organic frameworks (MOFs) are commended as photocatalysts for H evolution and CO reduction as they combine light-harvesting and catalytic functions with excellent reactant adsorption capabilities. For dynamic processes in liquid phase, the accessibility of active sites becomes a critical parameter as reactant diffusion is limited by the inherently small micropores. Our strategy is to introduce additional mesopores by selectively removing one ligand in mixed-ligand MOFs via thermolysis.