Thomas Bein

Ludwig-Maximilians-University of Munich | LMU · Department of Chemistry

To realize profitable applications with 2D-materials the transition from research scale to microelectronic fabrication methods is needed. This means the use of equipment for larger substrates and assessment of the process flows. In this study we demonstrate an effective way to assess MoS2 as semiconducting material, deposited with the lower priced...

Recently, the mixed‐dimensional (3D/2D or 3D/1D) perovskite solar cells using small organic spacers have attracted interest due to their outstanding long‐term stability. Here, a new type of thiophene‐based organic cation 2‐(thiophene‐2yl‐)pyridine‐1‐ium iodide (ThPyI), which is used to fabricate mixed‐dimensional 3D/1D perovskite solar cells, is pr...

Solar-driven photochemical CO2 reduction over semiconducting materials is a strategic technology towards sustainable development as it represents a source of renewable liquid and gaseous fuels, and simultaneously provides a solution for current environmental problems caused substantially by the accumulation of this greenhouse gas in the atmosphere....

Lead‐free double perovskites have attracted much attention as possible alternatives to lead halide based perovskites in photovoltaic applications. However, to date only few double perovskites have been successfully employed in optoelectronic device prototypes. Therefore, the search for stable and lead‐free materials is ongoing. Here, we present the...

In the field of perovskite solar cells, explorations of new lead-free all-inorganic perovskite materials are of great interest to address the instability and toxicity issues of lead-based hybrid perovskites. Recently, copper-antimony-based double perovskite materials have been reported with ideal band gaps, which possess great potential as absorber...

Thienothiophene thienoisoindigo (ttTII)-based covalent organic frameworks (COFs) have been shown to offer low band gaps and intriguing optical and electrochromic properties. So far, only one tetragonal thienothiophene thienoisoindigo-based COF has been reported showing stable and fast electrochromism and good coloration efficiencies. We have develo...

Although zinc oxide (ZnO) is one of the most commonly used materials for electron transport layers in organic solar cells (OSCs), it also comes with disadvantages such as the so‐called light‐soaking issues, i.e., its need for exposure to UV light to reach its full potential in OSCs. Here, the impact of ZnO light‐soaking issues on stability measurem...

The synthesis of homogeneous covalent organic framework (COF) thin films on a desired substrate with decent crystallinity, porosity, and uniform thickness has great potential for optoelectronic applications. We have used a solution-processable sphere transmutation process to synthesize 300 ± 20 nm uniform COF thin films on a 2 × 2 cm2 TiO2-coated f...

This study links the structural properties of EDOT-amide-TPA and its superior performance as hole transporting materials for perovskite solar cells.

Biomimetic mineralization of proteins and nucleic acids into hybrid metal-organic nanoparticles allows for protection and cellular delivery of these sensitive and generally membrane-impermeable biomolecules. Although the concept is not necessarily restricted to zeolitic imidazolate frameworks (ZIFs), so far reports about intracellular delivery of f...

Inflammation is required for protective responses against pathogens and is thus essential for survival, but sustained inflammation can lead to diseases, such as atherosclerosis and cancer. Two important mediators of inflammation are the cytokines IL-1β and IL-18, which are produced by myeloid cells of the immune system, including macrophages. These...

Two‐dimensional (2D) hybrid double perovskites are a promising emerging class of materials featuring superior intrinsic and extrinsic stability over their 3D parent structures, while enabling additional structural diversity and tunability. Here, we expand the Ag–Bi‐based double perovskite system, comparing structures obtained with the halides chlor...

As covalent organic frameworks (COFs) are coming of age, the lack of effective approaches to achieve crystalline and centimeter-scale-homogeneous COF films remains a significant bottleneck toward advancing the application of COFs in optoelectronic devices. Here, we present the synthesis of colloidal COF nanoplates, with lateral sizes of ∼200 nm and...

We present the synthesis of amorphous, mesoporous, colloidal magnesium phosphate-citrate nanoparticles (MPCs) from biogenic precursors, resulting in a biocompatible and biodegradable nanocarrier that amplifies the action of the anticancer drug methotrexate (MTX). Synthesis conditions were gradually tuned to investigate the influence of the chelatin...

Metal-organic frameworks (MOFs) featuring significant electrical conductivity constitute a growing class of materials, with intriguing possible applications as porous semiconductors or supercapacitors. If such features are combined with photoluminescence, additional functionalities such as selective chemical sensing become accessible. Here, we inco...

Since their introduction in 2017, the efficiency of lead-free halide perovskite solar cells based on Cs2AgBiBr6 has not exceeded 3%. The limiting bottlenecks are attributed to a low electron diffusion length, self-trapping events and poor selectivity of the contacts, leading to large non-radiative VOC losses. Here, 2D/3D hybrid double perovskites a...

By slowly evaporating organic solvents, we succeeded in growing lead-free double perovskite Cs 2 AgBiBr 6 crystals. Solubility curves prove the advantage of this growth technique and allow comparison with the controlled cooling...

Metal halide perovskites are the first solution processed semiconductors that can compete in their functionality with conventional semiconductors, such as silicon. Over the past several years, perovskite semiconductors have reported breakthroughs in various optoelectronic devices, such as solar cells, photodetectors, light emitting and memory devic...

To enable future large-scale generation of hydrogen via proton exchange membrane (PEM) electrolysis, utilization of scarce iridium-based catalysts required for the oxygen evolution reaction (OER) has to be significantly lowered. To address this question, the facile synthesis of a highly active TiO2 supported iridium oxide based OER catalyst with re...

We report the selective functionalization of the 1H-imidazo[1,2-b]pyrazole scaffold using a Br/Mg-exchange, as well as regioselective magnesiations and zincations with TMP-bases (TMP = 2,2,6,6-tetramethylpiperidyl), followed by trapping reactions with various electrophiles. In addition, we report a fragmentation of the pyrazole ring, giving access...

Freestanding electrodes are a promising way to increase the energy density of the batteries by decreasing the overall amount of electrochemically inactive materials. Freestanding antimony doped tin oxide (ATO)‐based hybrid materials have not been reported so far, although this material has demonstrated excellent performance in conventionally design...

As global warming caused by the greenhouse effect is becoming one of the major issues of the 21st century, hydrogen as an alternative to fossil-based fuels and other energy carriers has gained importance in current research. One promising approach to produce hydrogen is photoelectrochemical water splitting, which uses solar energy combined with sui...

Dynamische kovalente Chemie Die isoretikuläre Kristallisation von hoch porösen kubischen kovalent-organischen Käfigverbindungen wird von Florian Beuerle et al. im Forschungsartikel auf S. 17595 vorgestellt.

Dynamic Covalent Chemistry The isoreticular crystallization of highly porous cubic covalent organic cage compounds is reported by Florian Beuerle et al. in their Research Article on page 17455.

Cs2AgBiBr6 has attracted much interest as a potential lead-free alternative for perovskite solar cells. Although this material offers encouraging optoelectronic features, severe bottlenecks limit the performance of the resulting solar cells to a power conversion efficiency of below 3%. Here, the performance-limiting factors of this material are inv...

Fe-HHTP-MOF, a unique cubic metal–organic framework (MOF) comprising hexahydroxytriphenylene (HHTP) supertetrahedral units and FeIII ions arranged in a diamond topology is reported by Thomas Bein, Dana D. Medina et al. in their Research Article (DOI: 10.1002/anie.202102670). Fe-HHTP-MOF is a highly crystalline, porous and deep black material featur...

Fe-HHTP-MOF, ein einzigartiges kubisches metallorganisches Gerüst (MOF), das aus supertetraedrischen Hexahydroxytriphenylen(HHTP)-Einheiten und in Rautentopologie angeordneten FeIII-Ionen aufgebaut ist, wird im Forschungsartikel von Thomas Bein, Dana D. Medina et al. vorgestellt (DOI: 10.1002/ange.202102670). Fe-HHTP-MOF ist ein hochkristallines, p...

Modular frameworks featuring well‐defined pore structures in microscale domains establish tailor‐made porous materials. For open molecular solids however, maintaining long‐range order after desolvation is inherently challenging, since packing is usually governed by only a few supramolecular interactions. Here we report on two series of nanocubes ob...

Isoretikuläre poröse Materialien werden nach Kristallisation kubischer organischer Käfige mit unterschiedlichen Alkylketten an den Kanten erhalten. Stickstoff-Sorptionsmessungen ergaben Oberflächen bis zu 3426 m² g⁻¹ und Porenvolumina bis zu 1.84 cm³ g⁻¹. Die komplexe 3D-Anordnung alternierender intrinsischer und extrinsischer Poren bleibt beim Ent...

Here, we report the synthesis of a unique cubic metal‐organic framework (MOF), the Fe‐HHTP‐MOF, comprising hexahydroxytriphenylene (HHTP) supertetrahedral units and FeIII ions, arranged in a diamond topology. The MOF is synthesized under solvothermal conditions, yielding a highly crystalline, deep black powder, with crystallites of 300‐500 nm size...

Electrochromic coatings are promising for applications in smart windows or energy-efficient optical displays. However, classical inorganic electrochromic materials such as WO3 suffer from low coloration efficiency and slow switching speed. We have developed highly efficient and fast-switching electrochromic thin films based on fully organic, porous...

p>Modular frameworks featuring well-defined pore structures in microscale domains establish tailor-made porous materials. For open molecular solids however, maintaining long-range order after desolvation is inherently challenging, since packing is usually governed by only a few supramolecular interactions. Here we report on two series of nanocubes...

Nanoparticle-based delivery systems for cancer immunotherapies aim to improve the safety and efficacy of these treatments through local delivery to specialized antigen-presenting cells (APCs). Multifunctional mesoporous silica nanoparticles (MSNs), with their large surface areas, their tunable particle and pore sizes, and their spatially controlled...

Here, we report the synthesis of a unique cubic metal‐organic framework (MOF), the Fe‐HHTP‐MOF, comprising hexahydroxytriphenylene (HHTP) supertetrahedral units and FeIII ions, arranged in a diamond topology. The MOF is synthesized under solvothermal conditions, yielding a highly crystalline, deep black powder, with crystallites of 300‐500 nm size...

The efficiency of anti-cancer drugs is commonly determined by endpoint assays after extended incubation times, often after days. Here we demonstrate that curcumin encapsulated in crosslinked cyclodextrin nanoparticles (CD-NP) acts extremely rapidly on cell metabolism resulting in an immediate and complete inhibition of cell growth and in efficient...

A visible-light-driven oxidative 6π heterocycilization for the synthesis of structurally diverse π-conjugated polycyclic 1-aminoisoquinolines has been developed. The reaction proceeds under visible-light or sunshine, obviates photocatalyst and transition-metals, and features...

Covalent organic frameworks (COFs) are crystalline porous materials constructed from molecular building blocks using diverse linkage chemistries. Their modular construction system allows not only for tailor-made design but also for an immense variety of building blocks, opening the door to numerous different functionalities and potential applicatio...

Conventional chemotherapy leads to severe adverse effects since it involves systemic administration of toxic drugs at high dosage. Unlike traditional chemotherapeutics, calcium phosphate and citrate have both been discussed as very promising anticancer agents and are not inherently toxic. Yet, their breakthrough has been hampered by the lack of an...

Lead-free double perovskites have recently attracted growing attention as possible alternatives to lead-based halide perovskites in photovoltaics and other optoelectronic applications. The most prominent compound Cs 2 AgBiBr 6 , however, presents issues such as a rather large and indirect band gap, high exciton binding energies, and poor charge car...

Covalent organic frameworks define a versatile structural paradigm combining various attractive properties. The impact of different dopants on the conductivity of imine-linked 2D COFs featuring a redox-active Wurster-type motif was studied.

In this work we introduce the synthesis of a pillar‐like Co‐CAT‐1 MOF nanoarchitecture on gold‐coated woven stainless steel meshes. These nanostructured mesh surfaces feature extreme superhydrophilic and underwater superoleophobic wetting properties, allowing for gravity‐driven, highly efficient oil–water separation with ultra‐high flux of up to ne...

The rising demand for clean water for a growing and increasingly urban global population is one of the most urgent issues of our time. Particularly, the increasing generation of wastewater by cities and industrial sources requires the development of novel platforms for separating contaminants such as oils. Here, we introduce the synthesis of a uniq...

The transient photocurrent response of semiconductor electrodes to chopped illumination often shows spikes and overshoots that are usually interpreted as evidence that surface recombination is occurring. In the case of the high intensities used for light-driven water splitting, the interpretation is less straightforward since the electron transfer...

The low-temperature transition from a tetragonal to an orthorhombic crystal phase in methylammonium lead iodide (MAPI) is accompanied by drastic changes in the charge carrier mobility around a critical temperature of approximately 164K. This transition is studied here using the photoluminescence (PL) microscopy on large crystal MAPI thin films, whi...

Despite their immense potential, clinical translation of nanomedicines is hampered by physicochemical and biological barriers impairing cell‐specific targeting especially in solid tumors. In article number 2000017 Darcy E. Wagner, Silke Meiners and co‐workers report a novel approach using organ‐restricted vascular delivery (ORVD) with direct admini...

Multifunctional core-shell mesoporous silica nanoparticles (MSN) were tailored in size ranging from 60 to 160 nm as delivery agents for antitumoral microRNA (miRNA). The positively charged particle core with a pore diameter of about 5 nm and a stellate pore morphology allowed for an internal, protective adsorption of the fragile miRNA cargo. A nega...

Freestanding electrodes for lithium ion batteries are considered as a promising option to increase the total gravimetric energy density of the cells due to a decreased weight of electrochemically inactive materials. We report a simple procedure for the fabrication of freestanding LiFe0.2Mn0.8PO4 (LFMP)/rGO electrodes with a very high loading of act...

Nanoparticle‐based targeted drug delivery holds promise for treatment of cancers. However, most approaches fail to be translated into clinical success due to ineffective tumor targeting in vivo. Here, the delivery potential of mesoporous silica nanoparticles (MSN) functionalized with targeting ligands for epidermal growth factor receptor and C─C ch...

The efficiency of photoelectrochemical tandem cells is still limited by the availability of stable low band gap electrodes. In this work, we report a photocathode based on lithium doped copper (II) oxide, a black p-type semiconductor. Density functional theory calculations with a Hubbard U term show that low concentrations of Li (Li0.03Cu0.97O) lea...

Nanomedicines hold immense promise for a number of devastating diseases due to the ability to custom-design both the carrier and cargo. However, their clinical implementation has been hampered by physicochemical and biological barriers and off-target deposition which impair cell specific targeting, especially in internal organs. This study reports...

The presence of lead in novel hybrid perovskite-based solar cells remains a significant issue regarding commercial applications. Therefore, antimony-based perovskite-like A 3 M 2 X 9 structures are promising new candidates for low toxicity photovoltaic applications. So far, MA 3 Sb 2 I 9 was reported to only crystallize in the ‘zero-dimensional’ (0...

We report the syntheses of various compounds within the pseudo‑quaternary system of the type LiwNixCoyMnzOδ (δ ≤ 1) (pre‑NCMs). Four different compositions of this compound were realized as ultrasmall crystalline nanoparticles of 1‑4 nm diameter using low‑temperature solvothermal reaction conditions in tert‑butanol at only 170 °C. All of the pre‑NC...

In article number 1906670, Daniel Böhm, Dina Fattakhova‐Rohlfing, and co‐workers present a novel scalable approach for the design of a dimensionally stable iridium‐based oxygen evolution reaction (OER) catalyst architecture with a very low iridium volumetric loading density but very high OER activity, achieved by conformal deposition of ultrasmall...

Porous tin dioxide is an important low-cost semiconductor applied in electronics, gas sensors and biosensors. Here we present a versatile template-assisted synthesis of nanostructured tin dioxide thin films using cellulose nanocrystals (CNCs). We demonstrate that structural features of CNC-templated tin dioxide films strongly depend on the precurso...

Perovskite solar cells (PSCs) with a novel hybrid electrode structure, in which a single device can operate with either a vertical (sandwich) or lateral (back-contact) configuration of contacts, are demonstrated in this work. The hybrid structure was achieved by depositing an additional anode on top of a prefabricated back-contact PSC device, givin...

Charge transport in two zinc metal-organic frameworks (MOFs) has been investigated using periodic semiempirical molecular orbital calculations with the AM1* Hamiltonian. Restricted Hartree-Fock calculations underestimate the band gap using Koopmans theorem (ca. 2 eV compared to the experimental value of 2.8 eV). However, it almost doubles when the...

Covalent organic frameworks (COFs), consisting of covalently connected organic building units, combine attractive features such as crystallinity, open porosity and widely tunable physical properties. For optoelectronic applications, the incorporation of heteroatoms into a 2D COF has the potential to yield desired photophysical properties such as lo...

Hematite-based photoanodes have been intensively studied for photoelectrochemical water oxidation. The n -type dopant Sn has been shown to benefit the activity of hematite anodes. We demonstrate in this study that Sn-doped hematite thin films grown by atomic layer deposition can achieve uniform doping across the film thickness up to at least 32 mol...

A multistep synthesis procedure for the homogeneous coating of a complex porous conductive oxide with small Ir nanoparticles is introduced to obtain a highly active electrocatalyst for water oxidation. At first, inverse opal macroporous Sb doped SnO2 (ATO) microparticles with defined pore size, composition, and open‐porous morphology are synthesize...

The ability of growing covalent organic framework (COF) films allows for studying their properties as solid layers and enables the incorporation of these materials into a variety of functional devices. Here, we report on the fabrication of COF films and coatings by electrophoretic deposition (EPD). We demonstrate that the EPD technique is suitable...