Precursor Loading Research Articles

Alumina Coated with Titanium Dioxide Supported Iron for Hydrogen Production and Carbon Nanotubes via Methane Decomposition

Research on converting methane to hydrogen has gained more attention due to the availability of methane reserves and the global focus on sustainable and environmentally friendly energy sources. The decomposition of methane through catalysis (CDM) has excellent potential to produce clean hydrogen and valuable carbon products. However, developing catalysts that are both active and stable is a highly challenging area of research. Using titanium isopropoxide as a precursor and different loadings of TiO2 (10 wt.%, 20 wt.%, and 30 wt.%), alumina has been coated with TiO2 in a single-step hydrothermal synthesis procedure. These synthesized materials are examined as possible support materials for CDM; different wt.% of iron is loaded onto the synthesized support material using a co-precipitation method to enhance the methane conversion via a decomposition reaction. The result shows that the 20 wt.% Fe/20 wt.% Ti-Al (20Fe/20Ti-Al) catalyst demonstrates remarkable stability and exhibits superior performance, reaching a conversion rate of methane of 94% with hydrogen production of 84% after 4 h. The outstanding performance is primarily due to the moderate interaction between the support and the active metal, as well as the presence of the rutile phase. The 20Fe/30Ti-Al catalyst exhibited lower activity than the other catalysts, achieving a methane conversion of 85% and hydrogen production of 79% during the reaction. Raman and XRD analysis revealed that all the catalysts generated graphitic carbon, with the 20Fe/20Ti-Al catalyst specifically producing single-walled carbon nanotubes.

Print-Light-Synthesis of ruthenium oxide thin film electrodes for electrochemical sensing applications.

Print-Light-Synthesis (PLS) combines the inkjet printing of a ruthenium precursor ink with the simultaneous photo-induced generation of ruthenium oxide films. During PLS, inkjet-printing generates on conductive as well as insulating substrates micrometer-thin reaction volumes that contain with high precision defined precursor loadings. Upon direct UV light irradiation, the Ru precursor converts to RuO2 while all other ink components escape in the gas phase. No post PLS processes are required, and the as-obtained RuO2 films can be immediately used as electrochemical devices. Two-dimensional RuO2 patterns with micrometric resolution and highly-controlled ruthenium loadings (few µg/cm2) are realized. Thin RuO2 films are generated on insulating substrates, such as polyimide, as well as individual RuO2 particles on conductive substrates, such as graphene layers. The RuO2 films are characterized by electron microscopy and spectroscopic techniques. The sensoristic applicability of the PLS-RuO2 electrodes is demonstrated by potentiometric pH sensing in cell cultures and amperometric detection of L-cysteine. For pH sensing the RuO2 film electrodes show Nernstian sensitivity. L-cysteine detection of RuO2-modified graphene electrodes showed an electrocatalytical effect and resulted in the possibility of selectively detecting L-Cysteine also in presence of the interfering compound uric acid.

Hydrothermal synthesis of Nb2O5-natural zeolite composite for enhanced adsorptive removal of anionic and cationic dye

The imperative to mitigate dye pollution from wastewater has propelled the exploration of efficient adsorbents. This study deals with the preparation and evaluation of Nb2O5-supported natural zeolite (NbX_NZ) for enhanced dye adsorption performance. A facile hydrothermal method was employed to prepare NbX_NZ with varying niobium precursor loadings. Comprehensive material characterization employing FESEM, EDX, TGA, XRD, and FTIR analyses elucidate the successful incorporation of Nb2O5, revealing altered morphological and thermal properties. The adsorption test exhibited a notable augmentation in adsorption capacity for Congo red dye, particularly with the Nb15_NZ sample, showcasing a nearly two-fold increase compared to the parent natural zeolite. The findings underscore the potential of NbX_NZ as promising materials for anionic dye adsorption, paving the way for advancing wastewater treatment solutions and further investigations into metal oxide-modified zeolites.

Biocatalyst for carbon veil anode in microbial fuel cells: The effect of precursor and catalyst loading on overall performance

Biocatalysts in anodes have been crucial in improving microbial fuel cell (MFC) performance. Biocatalysts derived from biomass such as coconut wood sawdust (SD-B) and pepper processing residue (PS-B), were used to improve the electrocatalytic properties of Carbon Veil (CV) electrodes. The amorphous graphitic carbon biocatalyst with a mesoporous structure was found to have a surface area of 889.31 m2/g for SD-B and 763.56 m2/g for PS-B. Surface functional groups such as -OH which imparts hydrophilicity and -C=O and COOH which promotes bacterial compatibility have been revealed to be present in both catalysts. Catalyst loading played a major role and at an optimal loading of 2 mg/cm2, the electrodes exhibited maximum electrocatalytic activity in the case of both biocatalysts. The voltammetric capacitances of SD-B and PS-B modified electrodes were 191.6 mF/cm2 and 106.6 mF/cm2 demonstrating their pseudocapacitive behaviour too. The performance of MFC with SD-B revealed a maximum power density of 10.1 W/m3 (Open Circuit Voltage (OCV) of 850 mV), followed by PS-B at 6.89 W/m3 (OCV of 825 mV) whereas the plain CV was at 0.168 W/m3 (OCV of 760 mV). Anode polarization studies indicated reduced slopes for biocatalyst-modified anodes, signifying improved electrode kinetics, particularly notable in the SD-B modified MFC where the cathode became the limiting electrode. Coulombic efficiencies of the biocatalyst-modified MFCs increased to 54.50%, (SD-B 2 mg/cm2) and 37.78% (PS-B 2 mg/cm2) respectively from 12.74% as noticed in the case of unmodified MFC. This study emphasizes the potential of biocatalysts as a simple and low-cost means of enhancing the anode properties – porosity, conductivity, hydrophilicity, and biocompatibility.

X-ray characterization, structural analysis, antibacterial activity, and self-cleaning property of Cu-doped TiO2-SiO2 nanocomposite prepared by sonochemical process

TiO2-SiO2 nanocomposites with different copper (Cu) precursor loadings were prepared by a one-step sonochemical process. The mole ratio of Cu precursor in TiO2-SiO2 composite was varied at 0.004, 0.008, 0.020, and 0.040, respectively. The specific X-ray characterization techniques on crystalline structure, chemical composition, and chemical states of Cu-doped TiO2-SiO2 composite were carried out by X-ray diffraction technique (XRD), X-ray fluorescence (XRF), and X-ray photoelectron spectroscopy (XPS), respectively. Surface morphology and chemical bonding of Cu-doped TiO2-SiO2 composite were monitored by field emission scanning electron microscope (FE-SEM) and Fourier transform infrared spectrophotometer (FTIR). For antibacterial properties, the inhibition zone of antimicrobial activity was investigated by varying amounts of Cu precursors in the TiO2-SiO2 composite. After that, Cu-doped TiO2-SiO2 composite powder with different Cu precursor ratios was mixed in PMMA solution and deposited on glass slides to study the optical property and hydrophilicity by UV-VIS-NIR spectrophotometer and contact angle method. XRD patterns of Cu-doped TiO2-SiO2 nanocomposites show the formation of the main TiO2 anatase phase with the ultrafine particles observed by FE-SEM images. FT-IR spectra of the composites are assigned to the prominent peaks of the Ti-O-Ti and Ti-O-Si bond relating to the TiO2-SiO2 host matrix. Meanwhile, TiO2-SiO2 composites with Cu precursor at 0.004 mol ratio can significantly enhance the antibacterial activity with a large inhibition zone. The contact angle value of Cu-doped TiO2-SiO2 nanocomposite film at 0.040 Cu precursor mole ratio in the TiO2-SiO2 matrix resulted in the optimized composite ratio for achieving a hydrophilic surface on the substrate.

Natural vs. anthropogenic sources of N-Nitrosodimethylamine precursors in surface water

N-nitrosodimethylamine (NDMA) is a carcinogenic disinfection byproduct formed from reactions between dichloramine and organic nitrogen-containing precursors. It is unclear if NDMA precursors in surface water intakes originate in anthropogenic (i.e., wastewater) or natural sources. The Truckee River has a single point source release of treated wastewater effluent, making it an ideal system to study the relative importance of precursor sources. Three Lagrangian sampling events were conducted. NDMA formation potential (FP, a measurement of precursors) above the wastewater outfall indicated that the natural background of NDMA precursors was 2-28 ng/L. NDMA FP increased to 18-31 ng/L immediately downstream of the wastewater outfall, but decreased rapidly in a first order manner, and were not statistically different from the upstream samples in only ∼6 km. This suggests that the dominant source of NDMA precursors may be wastewater derived only near wastewater outfalls and deviates from the previous belief that wastewater-derived precursors are responsible for NDMA formation in drinking water sources located further downstream. Additionally, given the rapid loss of the wastewater precursors in this study, precursors which are slow to biodegrade/photolyze/adsorb to sediment are likely to be poor surrogates for the overall wastewater NDMA precursor pool. To understand temporal changes in the wastewater impact on environmental NDMA precursor loading, two 24-hour sampling events were conducted near (<3 km) the wastewater outfall and demonstrated that temporal changes in the NDMA precursors directly downstream of the wastewater outfall are directly linked to the wastewater flow contribution.

Curvature programming of freestanding 3D mesostructures and flexible electronics based on bilayer ribbon networks

Three-dimensional (3D) buckling assembly of flexible electronics from strategically designed two-dimensional (2D) precursor structures has enabled important applications in a variety of areas, owing to its versatile applicability to a broad range of length scales and high-performance materials, as well as to a rich diversity of 3D topologies. Rational design methods that allow direct mapping of 3D mesostructures onto unknown 2D precursor structures and loading parameters are foundational to these assembly technologies, but face scientific challenges, such as the high nonlinearity of spatial deformations and tricky bifurcation behaviors. While a few inverse design methods based on the beam theory, topology optimization and machine learning algorithms have been reported, the shape programming of freestanding 3D mesostructures/electronics with highly complex curvature distributions remains elusive. In this work, we propose a curvature programming method based on bilayer ribbon networks, along with a mold-assisted assembly strategy, as a new route to customizable freestanding 3D mesostructures and electronics. Combined mechanics modeling, finite element analyses and experimental measurements allow a clear understanding of nonlinear bending-stretching coupled deformations of bilayer ribbon networks during the 2D-to-3D transformation. A parameter domain with one-to-one mapping of the dimensionless curvature and the bending stiffness ratio is identified, offering a theoretical basis of the curvature programming. By introducing a discretization strategy, a variety of regular (e.g., circles, ellipses, spirals and toroids) and biomimetic 3D curved ribbons and mesosurfaces (e.g., mimicking wavy vines, diatoms and arbitrarily curled leaves) were inversely designed and experimentally realized. A device demonstration capable of strain/temperature sensing and micro-LEDs indication suggests application opportunities in bioelectronics and microelectromechanical systems.

Bacterial dealkylation of benzalkonium chlorides in wastewater produces benzyldimethylamine, a potent N-nitrosodimethylamine precursor

N-nitrosodimethylamine (NDMA) is a carcinogenic disinfection byproduct that forms during chloramine disinfection of municipal wastewater effluents which are increasingly used to augment drinking water supplies due to growing water scarcity. Knowledge of wastewater NDMA precursors is limited and the known pool of NDMA precursors has not closed the mass balance between precursor loading, precursor NDMA yield, and formed NDMA. Benzalkonium chlorides (BACs) are the most prevalent quaternary ammonium surfactants and have antimicrobial properties. The extensive utilization of BACs in household, commercial and industrial products has resulted in their detection in wastewater at elevated concentrations. We report the formation of a potent NDMA precursor, benzyldimethylamine (BDMA) from the biodegradation of BACs during activated sludge treatment. BDMA formation and NDMA formation potential (FP) were functions of BAC and mixed liquor suspended solids concentration at circumneutral pH, and the microbial community source. Sustained exposure to microorganisms reduced NDMA FP through successive dealkylation of BDMA to less potent precursors. BAC alkyl chain length (C8 – C16) had little impact on NDMA FP and BDMA formation because chain cleavage occurred at the C–N bond. Wastewater effluents collected from three facilities contained BDMA from 15 to 106 ng/L, accounting for an estimated 4 to 38 % of the NDMA precursor pool.

Relationship between deposition techniques and nanoparticle dispersions for flexible and printed electronics

Reverse micelles composed of polystyrene-b-poly(2-vinylpyiridine) have been used to synthesize nanoparticles composed of a wide range of materials, including metals, metal oxides, dielectrics, semiconductors perovskites, and core–shell nanoparticles. In this contribution, we examine the effect of deposition parameters on two-dimensional nanoparticle arrangements from colloidal solutions created using spin coating, dip coating, slot-die coating, and electrospray deposition. Despite the importance of achieving uniform coatings of ordered arrays of colloidal particles, previous studies have not thoroughly addressed this challenge. We show that the adjustability of interparticle distance depends on the deposition technique used and only occurs within the stable defect-free operating window of the deposition parameters. Establishing the specific operating window for each technique for a model system, we propose general guidelines that can be used for ensuring uniform coatings regardless of precursor loading and provide a guide for adjusting the deposition conditions when coating defects occur. We introduces a novel application of ellipsometry to evaluate interparticle spacing in nanoparticle arrays, enhancing our ability to assess film uniformity, allowing for quick and easy tuning of nanoparticle dispersion. Comparisons between spin, dip, and slot-die coating techniques reveal insights into the correlation between interparticle spacing and ordering, highlighting the importance of fitting relationships for various coating samples. This comprehensive comparison and discussion provide a roadmap for future research, outlining current challenges and trends and offering insights into achievable spacings and ordering in coating processes. This allows the classification of various deposition techniques with respect to their suitability for tailored applications.

Effect of loading and pyrolysis of carbon-supported cobalt phthalocyanine on the electrocatalytic reduction of CO2

Understanding the structure-activity relationship of materials that are active for the CO2 electrochemical reduction reaction (CO2ERR) is crucial for developing stable, high-performance catalysts. In this research, it is first shown that ball-milling is a highly efficient way to disperse cobalt phthalocyanine (CoPC) onto carbon black without influencing the CO2 electroreduction performance of the resulting materials. Then, the link between the loadings of the CoPC precursor on the carbon support and the CO2ERR activity of the pyrolyzed materials is demonstrated. With CO current efficiencies higher than 45% and CO current densities as high as -20 mA cm−2 at -0.77 V vs. RHE, the materials with CoPC loadings of 7.9 wt% and higher were still surprisingly active after pyrolysis at 800 and 900 °C. On the other hand, the CO2ERR activity of the materials containing less than 6.1 wt% CoPC was drastically reduced after pyrolysis at these temperatures, with CO current efficiencies lower than 10 %. X-ray powder diffraction revealed that only the materials containing crystalline CoPC before pyrolysis showed good CO2ERR activity after pyrolysis at 800 and 900 °C. Furthermore, X-ray absorption spectroscopy showed that the loading of the CoPC precursor influenced the structure of the active sites in the pyrolyzed CoPC/C materials. Overall, this study highlights the importance of the dispersion of CoPC when forming a material that is catalytically active for CO2ERR after pyrolysis.

Unprecedented selectivity behavior in the direct dehydrogenation of n-butane to n-butenes with similar active Pt nanoparticle size: unveiling structural and electronic characteristics of supported monometallic catalysts.

In this work, supported Pt monometallic catalysts were prepared using oxide and carbon supports by conventional impregnation methods. Similar Pt metallic nanoparticle sizes (mean sizes about 1.8-2 nm) have been obtained using different Pt precursor loadings (0.3 to 5 wt%). For comparison, catalysts with larger nanoparticle sizes were prepared using the liquid phase reduction method. Characterization results indicate different electronic and structural characteristics for the Pt nanoparticles, comparing nanoparticles with similar and different sizes, implying that both the Pt loading and the preparation method affect the formation of different metallic phases. We used the direct dehydrogenation of n-butane to n-butenes reaction as a test reaction to study the catalytic behavior of the Pt nanoparticles obtained at different Pt atomic concentrations. Surprisingly, Pt catalysts with the lowest metallic loading show the highest selectivities to olefins. Besides, Pt catalysts supported on carbon materials showed higher selectivity to butenes than those supported on oxide materials, this was attributed to a higher electron density in the Pt active sites. Likewise, at low Pt loadings, the CNP-supported Pt nanoparticles could be confined at the defect in the nanotube structure as crystalline agglomerates of atoms with few layers or monolayers with very few surface adatom or stepped adatom nanostructures or simply as a group of atoms, thus creating active Pt sites that favor the dehydrogenation reaction over secondary reactions.

Air-through-precursor suction-augmented replica molding for fabrication of anisotropic microparticles in gas-impermeable molds.

Replica molding (REM) is a powerful technique for fabricating anisotropic microparticles. Current REM methods rely on the use of gas-permeable molds for defect-free castings and facile particle recovery. However, they often encounter limitations on either technical accessibility or producible particle diversity. While the use of gas-impermeable molds presents a promising solution to these challenges, particle production within such molds necessitates addressing two critical issues: precursor loading and particle recovery. This study introduces a REM methodology specifically tailored to enable the production of anisotropic microparticles within gas-impermeable molds. To address the issue of precursor loading, our approach incorporates the air-through-precursor suction method, employing a degassed polydimethylsiloxane block to effectively eliminate air bubbles trapped in microwells. Additionally, fluorosilane pretreatment of the mold surface, along with the polyvinyl alcohol film formation, significantly enhances particle recovery up to 249-fold while ensuring particle homogeneity. This methodology demonstrates high adaptability to various gas-impermeable molds and curing techniques. The practical feasibility is illustrated through the successful production of functional composite microparticles that can be effectively utilized for oxygen sensing and self-assembly, challenging in conventional REM.

Construction of a polydopamine-MnO2 functionalized metal–organic framework for synergistic photothermal/NO/nanocatalytic antibacterial therapy

In this study, a multifunctional antibacterial platform was constructed that integrates photothermal/ NO/ nanocatalytic therapy by polydopamine (PDA)-MnO2 functionalized metal–organic framework with loading of NO precursor (NO@MOF@ PMnO2). The PDA coating imbues the nanoplatforms with photothermal performance. Furthermore, the heat generated from NIR could trigger a NO release, further augmenting the antibacterial activity. Moreover, the presence of the MnO2 component, which serves as a peroxidase nanozyme, catalyzes the enzymatic decomposition of H2O2 to generate hydroxyl radicals (·OH), increasing the permeability of the bacterial cell membrane and its sensitivity to heat and NO. As a result, the nanoplatform possesses an outstanding antibacterial performance against S. aureus and E. coli under the NIR laser. Therefore, the present study presents a photothermal/NO/nanocatalytic platform for synergistic antibacterial therapy.

Optimizing coupling effect of confined FeNi nanoalloys within graphitic carbon nanofibers to improve photothermal energy conversion efficiency for solar water purification

Sustainable and energy-efficient water purification by harnessing solar energy is critical to tackling the challenges of water scarcity and the on-going water pollution crisis. Nevertheless, the biggest challenge to the practical deployment of solar-driven water purification, however, continues to be the poor solar evaporation efficiency of materials. Herein, FeNi nanoalloys encapsulated in graphitic carbon nanofibers (FeNi3/CNF) using Prussian blue analogue (PBAs) derivatives were fabricated using electrospinning and carbonization. The PBAs metal precursors play a critical role in encapsulating and safeguarding the FeNi alloy nanostructures from oxidation and agglomeration challenges. Furthermore, the synergistic effects between the non-noble hybrid plasmonic nanoalloys and graphitic CNFs can be constructed and optimized from the mass loading of PBAs precursor. Benefiting from the broad solar absorption band, high specific surface area, abundant micro-mesopores, and well-organized interlayer channel, the resultant 2D FeNi3/CNF solar evaporator demonstrates an efficient water evaporation rate of 1.51 kg m-2h−1 with an outstanding solar evaporation efficiency of 93.3 % under one sun irradiation, among the best values reported thus far. Impressively, the resultant 2D FeNi3/CNF solar evaporator can be constructed using only 0.02 kg m−2 loading of photothermal materials without compromising evaporation performance, which highlights its cost-efficiency in the practical application. Furthermore, the desalinated water meets the drinking standards of the World Health Organization (WHO) with an efficient 99 % separation of multiple organic industrial dye pollutants. Hence, this work demonstrates an efficient cost-effective approach to novel non-noble plasmonic alloy-based metal–carbon composites for enhanced solar-driven interfacial evaporation and wastewater purification.

Wildfire impact on disinfection byproduct precursor loading in mountain streams and rivers

We investigated short (first post-fire precipitation)- and long-term (11-month) impacts of the Caldor and Mosquito Fires (2021 and 2022) on water quality, dissolved organic matter, and disinfection byproduct (DBP) precursors in burned and adjacent unburned watersheds. Both burned watersheds experienced water quality degradation compared to their paired unburned watersheds, including increases in dissolved organic carbon (DOC), dissolved organic nitrogen (DON), and DBP precursors from precipitation events. DBP precursor concentrations during storm events were greater in the Caldor Fire's burned watershed than in the unburned watershed; precursors of trihalomethanes (THMs), haloacetic acids (HAAs), haloacetonitriles (HANs), and haloacetamides (HAMs) were 533 µg/L, 1,231 µg/L, 64 and 58 µg/L greater. The burned watershed of the Mosquito Fire also had greater median concentrations of THM (44 µg/L), HAA (37 µg/L), HAN (7 µg/L), and HAM (13 µg/L) precursors compared to the unburned watershed during a storm immediately following the fire. Initial flushes from both burned watersheds formed greater concentrations of more toxic DBPs, such as HANs and HAMs. The Caldor Fire burn area experienced a rain-on-snow event shortly after the fire which produced the greatest degradation of water quality of all seasons/precipitation events/watersheds studied. Over the long term, statistical analysis revealed that DOC and DON values in the burned watershed of the Caldor Fire remained higher than the unburned control (0.98 mg C/L and 0.028 mg N/L, respectively). These short and long-term findings indicate that wildfires present potential treatment challenges for public water systems outside of the two studied here.

Print-Light-Synthesis for Single-Step Metal Nanoparticle Synthesis and Patterned Electrode Production.

The fabrication of thin-film electrodes, which contain metal nanoparticles and nanostructures for applications in electrochemical sensing as well as energy conversion and storage, is often based on multi-step procedures that include two main passages: (i) the synthesis and purification of nanomaterials and (ii) the fabrication of thin films by coating electrode supports with these nanomaterials. The patterning and miniaturization of thin film electrodes generally require masks or advanced patterning instrumentation. In recent years, various approaches have been presented to integrate the spatially resolved deposition of metal precursor solutions and the rapid conversion of the precursors into metal nanoparticles. To achieve the latter, high intensity light irradiation has, in particular, become suitable as it enables the photochemical, photocatalytical, and photothermal conversion of the precursors during or slightly after the precursor deposition. The conversion of the metal precursors directly on the target substrates can make the use of capping and stabilizing agents obsolete. This review focuses on hybrid platforms that comprise digital metal precursor ink printing and high intensity light irradiation for inducing metal precursor conversions into patterned metal and alloy nanoparticles. The combination of the two methods has recently been named Print-Light-Synthesis by a group of collaborators and is characterized by its sustainability in terms of low material consumption, low material waste, and reduced synthesis steps. It provides high control of precursor loading and light irradiation, both affecting and improving the fabrication of thin film electrodes.

Hydrodeoxygenation of lignin-derived diphenyl ether on in situ prepared NiMoS catalyst: The effect of sulfur addition on catalyst formation

The catalytic activity of unsupported NiMoS catalysts prepared in situ by thermal decomposition of the [(CH3)3S]2Ni(MoS4)2 precursor was studied in the course of diphenyl ether hydrodeoxygenation. The resulting catalysts were characterized using the transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). It was demonstrated that the diphenyl ether conversion naturally decreases with a decrease in the precursor loading. The effect of changes in the amount of the added sulfiding agent on the morphological and structural features of the formed catalysts was studied. It was found that reducing the amount of elemental sulfur from 2.5 to 0.5 wt% results in a more active sulfide NiMo catalyst, which is explained by an increase in the dispersion of the active phase particles from 0.24 to 0.34. A route of diphenyl ether hydrodeoxygenation on unsupported NiMoS catalysts was studied and suggested by varying the reaction time and hydrogen pressure in the system.

Optimization of 177Lu-labelling of DOTA-TOC, PSMA-I&T and FAPI-46 for clinical application

Background177Lu-radiopharmaceuticals are routinely used for the treatment of various tumor entities. The productions of radiopharmaceuticals follow strict good-manufacturing practice guidelines and synthesis optimizations thereof have a strong impact on e.g. the quality of the product, radiation safety and costs. The purpose of this study is to optimize the precursor load of three radiopharmaceuticals. For that, different precursor loads were evaluated and compared to previously reported findings.ResultsAll three radiopharmaceuticals were successfully synthesized in high radiochemical purities and yields on the ML Eazy. The precursor load was optimized for [177Lu]Lu-FAPI-46 from 27.0 to 9.7 µg/GBq, for [177Lu]Lu-DOTATOC from 11 to 10 µg/GBq and for [177Lu]Lu-PSMA-I&T from 16.3 to 11.6 µg/GBq.ConclusionsWe successfully reduced the precursor load for all three radiopharmaceuticals while maintaining their quality.

Effect of fly ash to slag ratio and Na2O content on leaching behaviour of fly Ash/Slag based alkali activated materials

Alkali–activated materials (AAMs) with variable levels of activator and precursor loading were evaluated for their long–term leaching behaviour. On a series of fly ash (FA)/slag–based binder mixes containing varying amounts of slag (0 – 30 wt%) and Na2O (5 – 9 wt%), 90–day leaching was conducted, and the resultant leaching products were characterized using X–ray diffraction, nuclear magnetic resonance 23Na and 27Al, and Fourier–transform infrared spectroscopy. The microstructural, mechanical, and physical properties of the samples were analysed as a function of the concentrations of activators and precursors. C–A–S–H and N–A–S–H gels were formed due to the inclusion of slag, which enhanced mechanical properties and decreased porosity. As the slag content in AAMs increased, the porosity decreased and the leaching ability of Na+ and Si4+ decreased. A long–term leaching process leached Ca2+ and Al[IV] from structural gels, including the N–A–S–H/C,N-A-S-H gel, and caused degradation with a corresponding decrease in compression strength and split tensile strength.

Effect of Fe on Calcined Ni(OH)2 Anode in Alkaline Water Electrolysis

Ni (hydr)oxide is a promising and inexpensive material for oxygen evolution reaction (OER) catalysts and is known to dramatically increase the activity when used with Fe. Herein, we basified a Ni(II) solution and coated layered Ni(OH)2 on Ni coins to prepare a template with high stability and activity. To evaluate the stability and catalytic activity during high-current-density operation, we analyzed the electrochemical and physicochemical properties before and after constant current (CC) operation. The electrode with a Ni(OH)2 surface exhibited higher initial activity than that with a NiO surface; however, after the OER operation at a high-current density, degradation occurred owing to structural destruction. The activity of the electrodes with a NiO surface improved after the CC operation because of the changes on the electrode-surface caused by the CC operation and the subsequent Fe incorporation from the Fe impurity in the electrolyte. After confirming the improvement in activity due to Fe, we prepared NiFe-oxide electrodes with improved catalytic activity and optimized the Ni precursor and Fe loading solution concentrations. The Ni-Fe oxide electrode prepared under the optimal concentrations exhibited an overpotential of 287 mV at a current density of 10 mA/cm2, and a tafel slope of 37 mV dec−1, indicating an improvement in the OER activity.