We present an all-atom model mimicking superparamagnetic iron oxide nanoparticles functionalized by alkyl phosphonic acids and demonstrate the prediction of grafting density, X-ray diffraction profiles, and solvent-dependent particle radii. The inherent complexity of this nanosystem calls for careful model preparation to avoid bias from human intuition. We suggest a cascade of simulated annealing steps for (i) providing reasonable starting points for the iron oxide particle and (ii) grafting by self-assembled monolayers. The latter was performed as a function of the number of phosphonic acid molecules deposited, thus offering an unbiased assessment of the grafting density and structural alignment of the tail groups that define the outer shell of the nanoparticle. The overall protocol is widely transferable and implies moderate computational costs as compared to the explicit modeling of phosphonic acid association from solution. In turn, solvent effects on the surface structure of the nanoparticle model initially prepared in the gas phase were considered using hexane, propanol, and water, respectively. Voronoi analyses clearly demonstrated the solvent-dependent bundling of the terminal alkyl groups of the phosphonic acids grafted onto iron oxide nanoparticles. To this end, the nanoparticle-solvent interface gives rise to nanometer-scale patterns of differently oriented monolayer structures.

The hydrodynamic size of magnetic nanoparticle clusters is a critical determinant of their in vivo behaviour and therapeutic efficacy. While alkaline co-precipitation offers a scalable route for polyacrylic acid (PAA) coated superparamagnetic iron oxide nanoparticles (SPIONs), it typically yields polydisperse agglomerates. This work establishes a predictive engineering process using controlled, post-synthesis ultrasound treatment to precisely tune SPION cluster size. Utilising a D-optimal Design of Experiments (DoE) approach, we modelled the influences of sonication parameters on the hydrodynamic diameter, identifying specific energy input as the governing factor for de-agglomeration. The resulting verified regression model (adj. R2=0.9986) enables predictable laboratory scale-up across varying volumes (1-10 ml) and concentrations (1-10 mg/ml) while maintaining material integrity. Quantitative magnetic characterisation revealed that ultrasound-induced fragmentation increases the mass-specific susceptibility, which is attributed to the magnetic de-locking of frustrated cores as inter-cluster spacing increases. Crucially, biological evaluations in B16-F10 melanoma cells demonstrate that this ultrasound-assisted size tuning directly influences cellular loading. Cellular iron mass post SPION incubation was found to follow a dual-variable dependency: while iron loading increases with cluster diameter for a fixed core size, it is significantly impacted by the primary core dimensions. SPION clusters with 12 nm cores exhibited a two-fold higher iron loading (8.23 pg Fe/cell) compared to those with 8 nm cores at equivalent hydrodynamic sizes, highlighting the importance of the magnetic payload per cluster. These findings establish a robust framework for engineering SPIONs with tailored dimensions to maximise and predict the magnetic responsiveness of loaded cells, providing a reliable foundation for future applications such as cell tracking, magnetic drug targeting, and hyperthermia.

Per- and polyfluoroalkyl substances (PFAS), known as “forever chemicals”, pose a persistent environmental threat due to their chemical stability, bioaccumulation and widespread presence in water sources. Traditional treatment methods are often limited to remove PFAS, especially at low concentrations or in complex mixtures. This study presents functionalized superparamagnetic iron oxide nanoparticles (SPIONs) to capture various PFAS, including amphiphilic and neutral compounds or even microplastics, from water. By tuning the SPION surface chemistry with a self-assembled monolayer (SAM) for electrostatic and hydrophobic interactions, we achieved high removal efficiencies in diverse conditions, including a contaminated drinking water source, soil wash-off, river water and laundry wastewater. Regenerable hydrophobic SPIONs maintained high performance, reducing PFAS levels up to 95.4%. These findings support SPIONs as a scalable, effective solution for broad-range PFAS removal even in complex environments. Their applicability across different matrices underscores their global relevance to mitigate PFAS pollution in industrial effluents, wastewater streams, and natural ecosystems.

Abstract Fused filament fabrication (FFF) 3D printing provides an accessible route to fabricating retrievable photocatalytic architectures with tunable geometry and composition. Here, we address the limited recoverability and reusability of conventional powder-based photocatalysts by translating a metal-free semiconductor catalyst to 3D printed electrodes. Graphitic carbon nitride (g-C3N4) was functionalized with carbonized polydopamine (cPDA) to create a modified photocatalyst with improved photophysical behavior, consistent, more effective charge separation, and longer-lived photoexcited states, which correlates with enhanced photocatalytic activity. The optimized formulation was compounded into an extrudable PLA-based composite filament and printed into electrodes containing either g-C3N4 or g-C3N4/cPDA. The printed g-C3N4/cPDA electrodes show enhanced photocatalytic rhodamine B degradation under simulated sunlight compared with unmodified printed electrodes. In contrast to suspended powders, the electrodes enable straightforward retrieval, improved operational stability, and reuse without postseparation steps. Furthermore, we demonstrate that electrode performance can be increased by scaling the surface area, highlighting geometry as a simple handle for upscaling. This work demonstrates the potential of photocatalytic 3D printed electrodes made from abundant materials via low-energy processing as a scalable and sustainable route for wastewater treatment.

Perovskite solar cells (PSCs) experience significant photovoltage losses due to nonradiative recombination, especially in p-i-n devices with Fullerene C60 as the electron transport layer (ETL), which limits device performance. To tackle this issue, we propose a strategy that synergistically suppresses nonradiative recombination at the perovskite/C60 interface by employing a 2D heterointerface with a two-site anchor bridge, which reduces the surface defect density. This process elevates the fermi level and enhances the electric field, facilitating electron extraction at the perovskite/C60 heterointerface. As a result, nonradiative recombination at this electron-selective perovskite contact is greatly suppressed. p-i-n PSCs fabricated using this interface engineering approach achieved a power conversion efficiency (PCE) of 26.32% and demonstrated excellent stability under continuous maximum power point tracking, along with an open-circuit voltage (Voc) of 1.217 V. This broadly applicable and scalable approach further delivers an impressive Voc of up to 1.368 V in wide-bandgap (1.8 eV) devices. Overall, the strategy offers a viable pathway toward efficient and stable inverted PSCs, demonstrating broad compatibility with diverse perovskite compositions.

Anthropogenic persistent organic pollutants pose a pressing threat to the environment and human health. They can be found in water bodies all around the world at low but hazardous concentrations. Typical representatives of this contaminant class are polychlorinated biphenyls (PCBs). Here, nanoparticulate core-shell water cleaning agents are presented, which are able to remove PCBs of various chlorination degrees from water. The core consists of superparamagnetic iron oxide nanoparticles (SPIONs) providing a large surface area that can be tuned via self-assembled monolayers (SAMs) composed of phosphonic acid derivates. This shell binds the pollutants non-covalently enabling facile magnetic water remediation. By employing positively charged or hydrophobic SAMs different PCBs can be preferentially removed. Furthermore, these orthogonal functionalities can be integrated into one SPION system. By combining charged and hydrophobic phosphonic acid derivates in so-called binary SAMs the removal preference can be convoluted, which works just as well in real river water. The cost-efficient availability of the base materials for these tailorable nanoparticles is complemented with recyclability laying the foundation for a sustainable water cleaning process.

Ligand engineering is an effective method to reduce defects in perovskite solar cells (PSCs) and to enhance efficiency. Likewise, enhancing device stability through ligand engineering is currently emerging as a key focus to suppress the bidirectional migration of halides and silver ions, which otherwise can cause irreversible chemical corrosion to the electrode and perovskite layer. Here, triphenylphosphine oxide (TPPO) is demonstrated to improve the long-term operational stability of PSCs when introduced at the interface between the perovskite and the electron transport layer (ETL). TPPO effectively eliminates uncoordinated Pb2+ and thus reduces surface defects. Accordingly, the target solar cell yields a hero power conversion efficiency (PCE) of 26.01% and a maximum open-circuit voltage (VOC) of 1.23 V, representing the minimum voltage deficit (0.32 V) reported for methylammonium-free (MA-free) PSCs. Moreover, long-term operational analysis reveals that the bidirectional migration of halides and silver ions is significantly suppressed, resulting in enhanced device stability. TPPO-modified PSCs retain 90% of the initial PCE after 1200 hours of operation in maximum power point tracking. Ligand engineering with TPPO marks a significant advancement in enhancing the stability of PSCs and is fully compatible to upscaling scenarios.

Self-assembled monolayers (SAMs) composed of various chemical moieties have been widely employed to engineer the surface functionality of nanomaterials. The incorporation of binary mixtures of SAM-forming ligands with distinct chemical structures and grafting behaviors enables the development of sophisticated surface properties. Precise control and characterization of the surface state are essential, and thus accessible analytical tools are needed to determine the composition of mixed SAMs. Fourier-transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR) is a widely used technique for investigating mixed SAMs on nanoparticles (NPs), providing qualitative insights into their chemical structure. Furthermore, quantitative analysis can be achieved by examining the IR absorbance peak intensity ratios. In this study, we present a comprehensive investigation of 15 different phosphonic acid (PA)-based ligands forming mixed SAMs on metal oxide NPs, aiming to promote the use of the IR absorbance peak ratio as a quantitative analytical method. Additionally, we establish a correlation between the ligand stoichiometry in solution during functionalization and the resulting surface composition in mixed SAMs, as governed by their grafting behavior. Our findings indicate a direct translation of the solution ratio to surface ratio for ligands with similar grafting behavior. However, in mixtures of ligands with different grafting behaviors, the ligand with a higher grafting density is overrepresented on the surface.

Ordered one dimensional perovskite single-crystal nanowire arrays, which combine high surface-to-volume ratios, directional charge transport, and mechanical flexibility, are typically prepared through solution or vapor phase techniques using templates of silicon, polydimethylsiloxane, photoresist, or aluminum oxide to control crystal growth. However, the size limits of these templates restrict the scalability of the arrays. Here, we introduce a dynamic template-assisted coating strategy that integrates blade coating to address this limitation. The method enables deposition of nanowire arrays on substrates with an area 12 times larger than the template. Incorporating a fluorinated passivating agent into the precursor suppresses surface defect formation and improves structural quality. Photodetectors based on MAPbBr3 arrays achieve a detectivity of 3.9 × 1014 Jones, a linear dynamic range of 160.3 dB, and a responsivity of 1660 A W-1, and retain 90.3% of their photocurrent after 300 h at 85% relative humidity without encapsulation.

Perovskite-organic tandem solar cells (P-O-TSCs) hold substantial potential to surpass the theoretical efficiency limits of single-junction solar cells. However, their performance is hampered by non-ideal interconnection layers (ICLs). Especially in n-i-p configurations, the incorporation of metal nanoparticles negatively introduces serious parasitic absorption, which alleviates photon utilization in organic rear cell and decisively constrains the maximum photocurrent matching with front cell. Here, we demonstrate an efficient strategy to mitigate optical losses in Au-embedded ICLs by tailoring the shape and size distribution of Au nanoparticles via manipulating the underlying surface property. Achieving fewer, smaller, and more uniformly spherical Au nanoparticles significantly minimizes localized surface plasmon resonance absorption, while maintaining efficient electron-hole recombination within ICLs. Consequently, optimized P-O-TSCs combining CsPbI2Br with various organic cells benefit from a substantial current gain of >1.5 mA/cm(2) in organic rear cells, achieving a champion efficiency of 25.34%. Meanwhile, optimized ICLs contribute to improved long-term device stability.

The wetting of (mixed) self-assembled monolayers (SAMs) is characterized as a function of surface charge. Using a combination of molecular dynamics simulations and contact angle measurements, we unravel the arrangement of dipoles and hydrogen bonds at the interface. Our basis simulation model features alkyl functionalization of an aluminum oxide surface via n-alkyl-phosphonic acid [C18H37-PO(OH)(2)] molecules, which represents a commonly used hydrophobic SAM surface readily accessible to contact angle measurements. We then probed the effect of charging the alkyl-terminated SAMs to unravel the interplay of local hydrophobicity and the overall dipole arrangement within the droplets. Strikingly, we find that moderate positive charging retains the hydrophobic character and potentially makes the SAMs even more hydrophobic than their uncharged counterpart. We attribute this phenomenon to the hindering of dangling hydrogen atoms at the water-alkyl contact, as a consequence of dipole rearrangements. While our simulation models predict a contact angle increase by 10 degrees as an upper estimate for boosting hydrophobicity, experimental analyses of mixed SAMs using imidazole/alkyl-terminated species showed roughly constant wetting behavior for moderately positive charging.

Polyethylene terephthalate (PET) is one of the most produced plastic materials in the world. The emer-gence of microplastics and nanoplastics (MPs/NPs) as a significant environmental contaminant has become a matter of increasing concern. While the toxicological effects of PET NPs have been widely re-searched, there is a lack of methodologies for studying their accumulation. The present study introduces a novel method to monitor the distribution of PET NPs in germinating wheat (Triticum aestivum L.) seeds. This involves the functionalization of superparamagnetic iron oxide nanoparticles (SPIONs) with PET NPs (PET-fSPION) coupled with magnetic resonance microimaging (µMRI) to provide insight into their distribution within the seed. The present study has demonstrated that PET-fSPION accumulates in specific regions of germinating wheat seeds, including the shoot apical meristem, the radicle, the cole-optile, the plumule, and the scutellum. Furthermore, the accumulation of PET-fSPION has been shown to exert a discernible effect on spin-spin relaxation, as observed via MRI and quantitative T2 relaxation time analysis. The accumulation of PET NPs in embryo regions was also confirmed by SEM. Diffu-sion-weighted magnetic resonance imaging (DW-MRI) and non-invasive chemical shift imaging analyses demonstrated that PET NPs resulted in restricted diffusion within the highlighted areas, as well as an impact on lipid content. Our study reveals that using µMRI with fSPION provides a non-invasive method to monitor the biodistribution of PET nanoparticles in wheat seeds. Additionally, it offers valuable in-sights into the microstructural interactions of PET.

Polyethylene terephthalate (PET) is one of the most produced plastic materials in the world. The emergence of microplastics and nanoplastics (MPs/NPs) as a significant environmental contaminant has become a matter of increasing concern. While the toxicological effects of PET NPs have been widely researched, there is a lack of methodologies for studying their accumulation. The present study introduces a novel method to monitor the distribution of PET NPs in germinating wheat (Triticum aestivum L.) seeds. This involves the functionalization of superparamagnetic iron oxide nanoparticles (SPIONs) with PET NPs (PET–fSPIONs) coupled with magnetic resonance microimaging (µMRI) to provide insight into their distribution within the seed. The present study has demonstrated that PET–fSPIONs accumulate in specific regions of germinating wheat seeds, including the shoot apical meristem, the radicle, the coleoptile, the plumule, and the scutellum. Furthermore, the accumulation of PET–fSPIONs has been shown to exert a discernible effect on spin–spin relaxation (T2), as observed via MRI and quantitative T2 relaxation time analysis. The accumulation of PET NPs in embryo regions was also confirmed by SEM. Diffusion-weighted magnetic resonance imaging (DW-MRI) and non-invasive chemical shift imaging analyses demonstrated that PET NPs resulted in restricted diffusion within the highlighted areas, as well as an impact on lipid content. Our study reveals that using µMRI with fSPIONs provides a non-invasive method to monitor the biodistribution of PET nanoparticles in wheat seeds. Additionally, it offers valuable insights into the microstructural interactions of PET.

Abstract Many charged organic molecules behave as persistent and hazardous pollutants with harmful effects on human health and ecosystems. They are widely distributed related to their charged molecular structure that provides water solubility. In order to track the fate and behavior of such pollutants, charged dyes with specific absorption in the visible spectra serve as convenient model compounds. We provide a platform of smart adsorbers that efficiently remediate positively and negatively charged dyes (crystal violet and Amaranth) from water. Metal oxide nanoparticles serve as a core with an intrinsically large surface area. The surface potential was tuned towards positive or negative by decorating the cores with self‐assembled monolayers of dedicated long‐chained phosphonic acid derivatives. Selective remediation of the dyes was obtained with corresponding oppositely charged core‐shell nanoparticles. Mixed dye solution can be cleaned by a cascade approach or by applying both particle systems simultaneously. The removal efficiency was determined as a function of particle concentration via UV‐spectroscopy. The results of remediation experiments at different pH values and using superparamagnetic iron oxide nanoparticle cores lead to a simple process with recycling capability.

Formamidinium (FA)-based perovskites exhibit significant potential for highly efficient photovoltaics due to their promising optoelectronic properties and optimal bandgap. However, the undesired inactive phase arises from multiple crystal nucleation pathways formed by various intermediate phases during the film formation process, persistently accompanying it. FA-based perovskites frequently struggle to form uniform, highly crystalline films. This challenge complicates the development of reliable and highly reproducible crystallization processes for perovskites and the establishment of guidelines for controlling the alpha-phase formation. In this work, we investigate the role of poly(acrylonitril-co-methyl acrylate) (PAM) to simultaneously control nucleation and subsequent alpha-phase crystallization. This successfully demonstrates the regulation of oriented crystal growth through the creation of a PAM-PbI2 intermediate. Ultimately, PAM-modified p-i-n architecture devices obtain a promising power conversion efficiency (PCE) of 25.30%, with V-OC (1.211 V), achieving 95% of the detailed balance limit. Additionally, PAM-modified devices maintain >= 90% of the initial efficiency for 1000 h under 1 sun and 65 degrees C operation.

Interface engineering is crucial to achieving stable perovskite photovoltaic devices. A versatile approach is developed to tailor interface properties via integrating co-assembled monolayers (co-SAMs) at the p-type buried interface and by capping a two-dimensional (2D) perovskite layer at the n-type upper interface with vacuum quenching. Optimized co-SAMs promote the coverage of the hole transport layer, significantly reducing the incidence of leakage currents. Based on this foundation, we develop damp-heat-stable perovskite solar cells by precisely tailoring the fragments of 2D perovskite layers through vacuum annealing with phenethylammonium iodide. An impressive open-circuit voltage of 1.216 V is achieved, corresponding to 92% of the value determined by the detailed-balance limit, along with a power conversion efficiency of 23.68%. Ultimately, integrating co-SAMs and the vacuum-assisted annealing fabricated devices maintain 96% and 80% of initial efficiencies after 1200 and 500 h of tracking at a maximum power point under 55 and 85(degrees)C, respectively.

Antimicrobial surfaces limit the spread of infectious diseases. To date, there is no antimicrobial coating that has widespread use because of short-lived and limited spectrum efficacy, poor resistance to organic material, and/or cost. Here, we present a paint based on waterborne latex particles that is supramolecularly associated with quaternary ammonium compounds (QACs). The optimal supramolecular pairing was first determined by immobilizing selected ions on self-assembled monolayers exposing different groups. The QAC surface loading density was then increased by using polymer brushes. These concepts were adopted to develop inexpensive paints to be applied on many different surfaces. The paint could be employed for healthcare and food production applications. Its slow release of QAC allows for long-lasting antimicrobial action, even in the presence of organic material. Its efficacy lasts for more than 90 washes, and importantly, once lost, it can readily be restored by spraying an aqueous solution of the QAC. We mainly tested cetyltrimethylammonium as QAC as it is already used in consumer care products. Our antimicrobial paint is broad spectrum as it showed excellent antimicrobial efficiency against four bacteria and four viruses.

Beyond their CO2 emittance when burned as fuels, hydrocarbons (HCs) serve as omnipresent raw materials and commodities. No matter if as liquid oil spills or the endless amounts of plastic roaming the oceans, HCs behave as persistent pollutants with water as main carrier to distribute. Even if their general chemical structure [-(CH2 )n -] is quite simple, the endless range of n leads to contaminations of different appearances and properties. A water remediation method based on superparamagnetic iron oxide nanoparticles (SPIONs) modified with self-assembled monolayers of alkyl phosphonic acid derivatives is presented. These molecules enable the SPIONs to non-covalently bind HCs, independently from the molecular weight, size and morphology. The attractive interaction is mainly based on hydrophobic and Coulomb interaction, which allows recycling of the SPIONs. The superparamagnetic core allows a simple magnetic collection and separation from the water phase which makes it a promising addition to wastewater treatment. Agglomerates of collected plastic "waste" even exhibit superior adsorption properties for crude oil, another hydrocarbon waste which gives these collected wastes a second life. This upcycling approach combined with presented recycling methods enables a complete recycling loop.

Soiling of solar cover glass is a major cause for efficiency loss of solar photovoltaic modules. Anti-soiling coatings can be used to reduce the rate of soiling and lower cleaning costs. The efficiency of these coatings has been demonstrated in laboratory and field tests, but the mechanisms and relevant parameters are still not well understood.In this article, we present a study on the influence of surface structure of hydrophilic sol-gel coatings on their anti-soiling performance in terms of both, dust accumulation and subsequent indoor tests for dust removal by wind. The surface structure of the films originates from the addition of colloidal silica particles of different sizes to the sols used for film preparation. In the dust deposition experiments, standardized test dust and dust collected from solar installations were used. Repeated tests were conducted under controlled humidity.In the case of dust deposition, the accumulation of dust particles larger than -10 mu m is strongly reduced, in relation to bare glass, by the anti-soiling effect of all coatings regardless of their surface structure.For the dust removal via wind, coatings that bear a smoother surface structure are cleaned more easily than coatings with a rougher surface structure. Additionally, larger and rounder dust particles are removed more easily from coatings with a rougher surface structure (structure height over -40 nm), while smaller and more irregularly shaped dust particles are removed more easily from coatings with a smoother surface structure.

Clean water is one of the most important resources of the planet but human-made contamination with diverse pollutants increases continuously. Microplastics (<5 mm diameter) which can have severe impacts on the environment, are present worldwide. Degradation processes lead to nanoplastics (<1 µm), which are potentially even more dangerous due to their increased bioavailability. State-of-the-art wastewater treatment plants show a deficit in effectively eliminating micro- and nanoplastics (MNP) from water, particularly in the case of nanoplastics. In this work, the magnetic removal of three different MNP types across three orders of magnitude in size (100 nm-100 µm) is investigated systematically. Superparamagnetic iron oxide nanoparticles (SPIONs) tend to attract oppositely charged MNPs and form aggregates that can be easily collected by a magnet. It shows that especially the smallest fractions (100-300 nm) can be separated in ordinary high numbers (1013  mg-1 SPION) while the highest mass is removed for MNP between 2.5 and 5 µm. The universal trend for all three types of MNP can be fitted with a derived model, which can make predictions for optimizing SPIONs for specific size ranges in the future.