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[Display omitted] • CuAl-LDH/g-C 3 N 4 heterostructures were successfully fabricated via non-covalent co-assembling. • CuAl-LDH/g-C 3 N 4 own higher separation and transportation of charge carrier at interface. • The introduction of CuAl-LDH extends the photoresponse to long wavelength region. • CuAl-LDH/g-C 3 N 4 exhibited outstanding visible-light photoactivity towards H 2 and O 2 generation. • CB and VB positions of CuAl-LDH/g-C 3 N 4 heterojunction suggest a S-scheme mechanism. CuAl layered double hydroxide (LDH) and polymeric carbon nitride (g-C 3 N 4 , GCNN) were assembled to construct a set of novel 2D/2D CuAl-LDH/GCNN heterostructures. These materials were tested towards H 2 and O 2 generation from water splitting using visible-light irradiation. Compared to pristine materials, the heterostructures displayed strongly enhanced visible-light H 2 evolution, dependent on the LDH content, which acts as a cocatalyst, replacing the benchmark Pt. The optimal LDH loading was achieved for 0.2CuAl-LDH/GCNN that exhibited an increased number of active sites and showed a trade-off between charge separation efficiency and light shading, resulting in a 32-fold increase in the amount of evolved H 2 compared with GCNN. In addition, the 0.2CuAl-LDH/GCNN heterostructure generated 1.5 times more O 2 than GCNN. The higher photocatalytic performance was due to efficient charge carriers' separation at the heterojunction interface via an S-scheme (corroborated by work function, steady-state and time-resolved photoluminescence studies), enhanced utilisation of longer-wavelength photons (>460 nm) and higher surface area available for the catalytic reactions. [ABSTRACT FROM AUTHOR]

One of the fundamental questions in developmental biology is what determines the final size and shape of an organ. Recent research strongly emphasizes that besides cell-cell communication, biophysical principals govern organ development. The architecture and mechanics of a tissue guide cellular processes such as movement, growth or differentiation. Furthermore, mechanical cues do not only regulate processes at a cellular level but also provide constant feedback about size and shape on a tissue scale. Here we review several models and experimental systems which are contributing to our understanding of the roles mechanical forces play during organ development. One of the best understood processes is how the remodeling of bones is driven by mechanical load. Culture systems of single cells and of cellular monolayers provide further insights into the growth promoting capacity of mechanical cues. We focus on the Drosophila wing imaginal disc, a well-established model system for growth regulation. We discuss theoretical models that invoke mechanical feedback loops for growth regulation and experimental studies providing empirical support. Future progress in this exciting field will require the development of new tools to precisely measure and modify forces in living tissue systems. [ABSTRACT FROM AUTHOR]

Abstract: We investigate how residual catalyst from carbon nanotube (CNT) templates can be used to engineer novel functional nanomaterials. CNTs, produced via continuous flow chemical vapour deposition, typically contain catalyst residues in the form of encapsulated metal clusters or of iron oxide nanoparticles attached to the outside of the CNTs. These CNTs are used as sacrificial templates for TiO2 coatings using benzyl alcohol as a linking agent. Upon oxidation of the CNTs, the encapsulated iron particles dissolve into the TiO2 lattice and form iron-doped TiO2 nanotubes without the formation of secondary phases, while the iron oxide particles merely attach to the outer surface. The materials show extended light absorption into the visible range, a requirement for visible-light photocatalyst. [Copyright &y& Elsevier]

The article focuses on the properties and application of carbon nanotubes (CNTs)-inorganic hybrids, a new type of hybrid materials developed from CNTs. It states that this kind of functional material replaces the organic compound with CNTs and combines the multiphase characteristics of nanocomposites with hybrid frameworks' functions. It projects that it has the capacity to trap electrons and reduce the rate of electron-hole recombination in some applications such gas sensors and photovoltaics.

Hydrogen treatment of Pt/TiO2 leads to an exceptional increase in electric conductivity even at moderate temperature presumably due to the formation of donor electrons during a superficial reduction process. Interestingly, after cooling to lower temperatures that are typically applied for catalytic reactions the observed high conductivity was largely preserved. The enhanced charge carrier density in titania is assumed to cause a considerable charge transfer between support and metal. In this work we show that this charge transfer is correlated with typical catalytic parameters (e.g. hydrogen adsorption capacity and catalytic activity for a hydrocarbon skeleton reaction). Based on these observations we suggest and discuss a modified charge transfer mechanism in addition to the decoration mechanism as a possible reason for the SMSI effect occurring during hydrogen treatment already at moderate temperatures. [ABSTRACT FROM AUTHOR]

The electric charge transport in oxygen-treated titania is accomplished via two different routes. One of these pathways (A) occurs by electronic transport through the bulk phase with additional contributions from transfer through grain boundaries and between the electrode and the grains. As a parallel conduction pathway (B) ions can move along the grain surface parallel to the electric field and can surmount the grain boundaries between the grains. Because of the low voltage applied, the ion discharge at the electrode by electrochemical reaction is impeded and contributes a capacitive impedance only. According to this mechanism an equivalent circuit model was proposed that fits excellently the experimental data. When samples with a low surface area are treated in oxygen, the charge is transported mostly by electrons via pathway A. The electrons are formed by removal of oxygen leaving a surface oxygen vacancy and two electrons in the titania. Since the formation of these charge carriers is highly endothermic, the apparent activation energy of this mechanism is higher than that of the ionic conduction and thus the ionic transport along the surface becomes more important at lower temperatures. The contribution of the ionic conduction becomes important only in samples with a high surface area. When titania is treated in hydrogen the conductance is drastically increased, since surface oxygen ions are removed more easily due to reaction with hydrogen. The apparent activation energy for electronic conduction becomes smaller because the enthalpy of vacancy formation is decreased by the formation energy of water. Thus, in hydrogen treated titania the conduction is accomplished exclusively by electronic transport. [ABSTRACT FROM AUTHOR]

Efficiently generating C1 building blocks from environmentally friendly carbon sources, such as through photocatalytic CO2 reduction, is essential for fostering a sustainable circular economy. The pursuit of mild catalytic activation methods has yielded powerful catalysts that can be synergistically employed alongside various reaction media to enhance overall performance. Herein, we elucidate the influence of diverse imidazolium‐based ionic liquids as additives for visible‐light‐driven CO2 reduction with ruthenium(II)‐ and rhenium(I)‐bipyridine complexes. Our investigation reveals that incorporating ionic liquids into traditional solvents at concentrations below 10 % can markedly boost CO production while suppressing H2 generation. The best results were obtained for the highly basic ionic liquid [C2mim][OAc], resulting in a substantial rise in CO formation from 0.3 μmol/h to 5.4 μmol/h and an increase in turnover number from 3 to 59. This study underscores the cooperative influence of imidazolium‐based ionic liquids on CO2 photoreduction while circumventing their use as primary solvents, thus offering a promising avenue for sustainable chemical synthesis. [ABSTRACT FROM AUTHOR]

Replacement of protecting ligands of gold nanoclusters by ligand exchange has become an established post-synthetic tool for selectively modifying the nanoclusters' properties. Several Au nanoclusters are known to additionally undergo size transformations upon ligand exchange, enabling access to cluster structures that are difficult to obtain by direct synthesis. This work reports on the selective size transformation of Au15(SG)13 (SG: glutathione) nanoclusters to Au16(2-PET)14 (2-PET: 2-phenylethanethiol) nanoclusters through a two-phase ligand exchange process at room temperature. Among several parameters evaluated, the addition of a large excess of exchange thiol (2-PET) to the organic phase was identified as the key factor for the structure conversion. After exchange, the nature of the clusters was determined by UV–vis, electrospray ionization-time of flight mass spectrometry, attenuated total reflection-Fourier transform infrared, and extended x-ray absorption fine-structure spectroscopy. The obtained Au16(2-PET)14 clusters proved to be exceptionally stable in solution, showing only slightly diminished UV–vis absorption features after 3 days, even when exposed to an excess of thiol ligands. [ABSTRACT FROM AUTHOR]

Metal‐organic frameworks (MOFs) are promising materials for photocatalytic water splitting reactions, but examples of visible light‐responsive, catalytically active, and stable MOFs are still rare. A detailed investigation is conducted for COK‐47 – a recently described MOF comprising 2D Ti‐O6 secondary building units (SBUs) – toward a photocatalytic hydrogen evolution reaction (HER), showing how overall particle morphology, surface area, and missing ligand defects are central parameters governing the material's ultimate performance. The newly synthesized COK‐47ISO is among the most active MOFs to date, yielding HER‐rates of 8.6 µmol h−1, and an apparent quantum yield (AQY) of 0.5% under visible light illumination. Optoelectronic and photoluminescence investigations, supported by theoretical calculations, enable the unraveling of its electronic structure along with charge transfer and recombination kinetics. A wavelength‐dependent reaction mechanism is proposed involving ligand to metal charge transfer (LMCT) and the main challenges for visible or UV photoexcitation are identified, demonstrating that the unique 2D layered structure aids charge separation and is key to the high performance. This work introduces COK‐47 as a promising alternative to the well‐known MIL‐125 family and offers directions for future studies [ABSTRACT FROM AUTHOR]

The selective removal of one ligand in mixed‐ligand MOFs upon thermolysis provides a powerful strategy to introduce additional mesopores without affecting the overall MOF structure. By varying the initial ligand ratio, MOFs of the MIL‐125‐Ti family with two distinct hierarchical pore architectures are synthesized, resembling either large cavities or branching fractures. The performance of the resulting hierarchically porous MOFs is evaluated toward the adsorptive removal of glyphosate (N‐(phosphonomethyl)glycine) from water, and the adsorption kinetics and mechanism are examined. Due to their strong affinity for phosphoric groups, the numerous Ti–OH groups resulting from the selective ligand removal act as natural anchor points for effective glyphosate uptake. The relationships between contact duration, glyphosate concentration, and adsorbent dosage are investigated, and the impact of these parameters on the effectiveness of glyphosate removal from contaminated water samples is examined. The introduction of additional mesopores has increased the adsorption capacities by nearly 3 times with record values exceeding 440.9 mg g−1, which ranks these MOFs among the best‐reported adsorbents. [ABSTRACT FROM AUTHOR]

[Display omitted] Metal-organic frameworks (MOFs) hold potential for promoting the redox reaction of sulfur species (RRS) and suppressing the shuttle effect in lithium–sulfur batteries (LSBs). However, except for a limited number of frameworks, most MOFs are found to be inert in accelerating RRS, which is largely related to the fact that their design principles and mechanism of catalysis have not been fully understood. Systematic density functional theory (DFT) calculations and experimental results reveal that the lack of exposed polar catalytic sites restricts MOF's potential in promoting RRS. Herein, based on a series of multivariable MOFs containing ligands with different thermal stability, selective ligand removal and ligand exchange (LE) strategies were applied successively to expose the catalytic metal clusters and introduce extra adsorption sites, rendering inert MOFs into catalytic ones. Such post-modified multivariable MOFs were shown to yield LSBs with remarkably improved specific capacity and cycling stability realizing 7.9 mAh cm−2 of capacity after 100 cycles at high sulfur loading of 8.1 mg·cm−2 under a lean electrolyte condition. The universal strategy proposed in this work will guide the design of catalytic MOFs for RRS and promote the development of advanced catalysts for high-performance LSBs. [ABSTRACT FROM AUTHOR]

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 (CO2) reduction and hydrogen (H2) evolution, is a promising method. Often, noble metal catalysts such as gold or silver are used, but those metals are costly and have limited availability. Here, we show that metal-organic chalcogenolate assemblies (MOCHAs) combine several properties of successful electrocatalysts. We report a scalable microwave-assisted synthesis method for highly crystalline MOCHAs ([AgXPh] ∞: X = Se, S) with high yields. The morphology, crystallinity, chemical and structural stability are thoroughly studied. We investigate tuneable syngas production via electrocatalytic CO2 reduction and find the MOCHAs show a maximum Faraday efficiency (FE) of 55 and 45% for the production of carbon monoxide and hydrogen, respectively. Syngas is an industrially highly relevant gaseous mixture of carbon monoxide and hydrogen, but its production is energy-intense and relies on natural gas precursors and noble-metal catalysts. Here, the authors explore metal-organic chalcogenolate assemblies (MOCHAs) for tuneable syngas production via electrocatalytic CO2 reduction. [ABSTRACT FROM AUTHOR]

Recently, carbon spherogels have been introduced as a novel monolithic aerogel composed of hollow spheres. This material is conveniently obtained via polystyrene (PS) sphere templating. In the present study, we apply a water-soluble titania precursor (titanium(IV) bis(ammonium lactate) to the aqueous sol-gel synthesis based on resorcinol-formaldehyde (RF) to effectively encapsulate titania. In this way, a very high mass loading of up to 59 mass% of titania can be confined strictly to the inside of the hollow carbon spheres. In the final synthesis step, carbonization at 800 °C has three simultaneous effects: Transformation of the RF coating on PS into microporous carbon, PS template removal by decomposition, and formation of titania due to precursor dissociation. A deliberate tuning of the microporous carbon shell, accessibility of the titania, titania amount, and titania's polymorph is further demonstrated by thermal treatment under a carbon dioxide atmosphere. In contrast to non-tuned or TiC-containing carbon spherogels, CO 2 activation of the composites results in a three orders of magnitude rise of their photocatalytic activity towards hydrogen evolution reaction, which we evaluate using flow and batch reactors. We further show that this effect is related to the partial etching of the carbon shell, which renders the TiO 2 surface accessible to the reactants in the solution and allows for an efficient hole scavenging. Given the simplicity of the hybrid carbon spherogel (HCS) composite fabrication, the high degree of control of their morphological characteristics, and the striking effects of CO 2 -activation on performance, we believe that our results will contribute to the development of similar carbon-inorganic composites. [Display omitted] [ABSTRACT FROM AUTHOR]

The design and development of porphyrinic POM-based MOFs (POMMOFs) represents an advanced approach to building materials that seamlessly integrate the collective strengths of POMs, porphyrins, and MOFs into a single framework. POMMOFs thus showcase their ability to combine predictable redox chemistry and biomimetic functions with the exceptional porosity of the resulting matrix. This review outlines the synthesis techniques and diverse catalytic applications of these materials, paving the path for further exploration and advancement of POMMOFs. [Display omitted] • This article demonstrates the incorporation of POMs, either encapsulated within the cavity or embedded within the structural framework of porphyrinic MOFs. • The possibility of integration of multiple metalloporphyrin linkers within POM-based MOFs is highlighted. • A detailed discussion of the innovative synthetic approaches utilized in crafting POM-based porphyrinic MOFs, along with their various applications in heterogeneous catalysis, is provided. • Despite being fabricated infrequently up to now, the impact of existing POMMOFs on shaping the future design of such materials is highlighted. The ever-increasing appearance of inorganic–organic hybrid materials incorporating organic metalloporphyrins (MPs) and inorganic polyoxometalates (POMs) – separately, two groups of effective molecular catalysts – which combine to form the ground-breaking class of metal–organic frameworks (MOFs), has allowed this class to participate in numerous kinds of chemical reactions and mimic the activity of heterogeneous bio-, photo- and electrocatalysts. Recent results have shown that the integration of POMs and MPs in a porous structure not only maintains the characteristic functionalities of both components, but can also generate novel and unparalleled features including augmented stabilities, remarkable selectivity, improvable porosity, and novel and more favorable topologies. Furthermore, the immobilization of these component species (POMs and MPs) within a unified framework can prevent their catalytic deactivation, which mostly arises from suicidal self-oxidation of porphyrin moieties. It has also been established that the introduction of POMs – owing to their broad range of size, structure, and highly negative charge distribution throughout the cluster – can further expand their structural diversity and greatly influence the stability and catalytic performance of porous porphyrinic MOFs. What is more, the incorporation of POMs inside the pores or their use as secondary building units (SBUs) within the framework can give rise to an increase in their original reusability, perpetuity, and adsorption ability. Moreover, their incorporation can also boost the transfer of electrons (e.g., photoexcited charge carriers) through the network. Therefore, POM-based porphyrinic MOFs (porphyrinic POMMOFs) are materials that can simultaneously take advantage of the combined uniqueness of the individual traits of POMs, porphyrins and MOFs, which display rich redox photochemistry, biomimetic ability, and porosity, respectively. This review aims to represent the latest progress in porous porphyrinic POMMOFs, encompassing their categorization, fabrication and exploitation in the catalysis field. To the best of our knowledge, hitherto no specific attempt has been made to cover this topic, and our review would be the first systematic scrutiny of these porous materials. Last but not least, the POMs that have been templated to synthesize porphyrinic POMMOFs are still mostly limited to a few types of POMs. Moreover, the porphyrin linkers which were used to create such MOFs have also been confined to only a few kinds. Thus, we suggest that other POMs ((iso-) heteropolyoxometalates) and porphyrin-based linkers could be explored, with an eye to creating new state-of-the-art porphyrinic POMMOFs. In the short term, it is anticipated that this review will encourage scientists to substantially extend the frontiers of knowledge about these systems, not only in the area of catalysis, but also in such versatile and underexplored domains as magnetism, gas sorption, sensing, biomedicine, and electrochemical and photocatalytic utilizations. For these reasons, we strongly believe that this comprehensive review will not only provide a better overview of the subject, but also open up promising directions of research and stimulate scientific interest and enthusiastic curiosity. It will also pave the way to generating important new ideas for the future of the synthesis and applications of these invaluable types of MOFs. [ABSTRACT FROM AUTHOR]

Abstract: We synthesized highly porous composite films of vertically aligned carbon nanotubes (CNTs) and polypyrrole (PPy) by employing a simple in situ electropolymerisation process from aqueous pyrrole solutions. By contacting the entire CNT array, each CNT acts as a highly active anode that facilitates uniform deposition and immediate polymerization of pyrrole directly on the CNT surface. As a result, each individual CNT was coated with a thin layer of PPy with a tunable thickness between 4 and 38nm. At the same time the vertical array structure of the CNTs was preserved. A major advantage of this route is that the resulting composite film is highly porous and can be post-filled with other polymers, metals or ceramics to create new multifunctional composites and hybrid structures. [Copyright &y& Elsevier]

[Display omitted] • Acetate ion functionalized polar ionic liquid (IL), 1-allyl-3-methylimidazolium acetate (AMIMOAc), has firstly been used not only as an additive in MAPbI 3 perovskite film but also as an interfacial modification layer between SnO 2 and MAPbI 3 in carbon counter electrode-based perovskite solar cells. • The appropriate content of IL can reduce the number of trap states in MAPbI 3 perovskite film to inhibit non-radiative recombination and increase carrier lifetime, further improve the PCE to 15.16%. • The stability of the devices has been improved remarkably. The device with AMIMOAc IL has retained 93% of its initial PCE after storing for 500 h. The potential of perovskite solar cells as a representative alternative to silicon-based solar cells has become significant owing to their unparalleled advancement in efficiency. However, the intrinsic instability of perovskite still hinders their large-scale commercial application, particularly of the decomposition of perovskite during device operation. To address this issue, an acetate-ion-functionalized polar ionic liquid, 1-allyl-3-methylimidazolium acetate (AMIMOAc), is used as an additive in MAPbI 3 film. FTIR spectroscopy measurements show that AMIMOAc can anchor the organic cations via hydrogen bonding and enhance the Pb–O interaction in modified MAPbI 3 , leading to a continuous and dense morphology to increase the stability of MAPbI 3. After optimizing the concentration of AMIMOAc, an additional interfacial modification layer accelerates the electron extraction and transport. By the synergy of both additive engineering and interface modification, the device not only achieves a high efficiency of 15.16%, but also maintains 93% of the initial PCE after 500 h, showing significantly improved stability. These results pave the way to a new strategy to improve efficiency and long-term stability of carbon counter electrode-based PSCs. [ABSTRACT FROM AUTHOR]

Hole transport layers (HTLs) play a key role in perovskite solar cells (PSCs), particularly in the inverted PSCs (IPSCs) that demand more in its stability. In this study, samarium‐doped nickel oxide (Sm:NiOx) nanoparticles are synthesized via a chemical precipitation method and deposited as a hole transport layer in the IPSCs. Sm3+ doping can reduce the formation energy of Ni vacancy and naturally increase the density of Ni vacancies, thereby rendering increased hole density. Thenceforth, the electronic conductivity is enhanced significantly, and work function enlarged in the Sm:NiOx film in favor of extracting holes and suppressing charge recombination. Consequently, the Sm:NiOx‐based IPSCs attain outstanding power conversion efficiencies as high as 20.71%. Even when it is applied in flexible solar cells, it still outputs efficiency as high as 17.95%. More importantly, the Sm:NiOx is compatible with large‐scale processing whereby the large area IPSCs of 1.0 cm2 and 40 × 40 mm2 deliver high efficiencies of 18.51% and 15.27%, respectively, all are among the highest for the inorganic HTLs based IPSCs. This research demonstrates that, while revealing the doping effect in depth, Sm:NiOx can be a promising hole transport material for fabricating efficient, large‐area, and flexible IPSCs in the future. [ABSTRACT FROM AUTHOR]

Over seventy years ago, Niels Bohr described how the charge state of an atomic ion moving through a solid changes dynamically as a result of electron capture and loss processes, eventually resulting in an equilibrium charge state. Although obvious, this process has so far eluded direct experimental observation. By peeling a solid, such as graphite, layer by layer, and studying the transmission of highly charged ions through single-, bi- and trilayer graphene, we can now observe dynamical changes in ion charge states with monolayer precision. In addition we present a first-principles approach based on the virtual photon model for interparticle energy transfer to corroborate our findings. Our model that uses a Gaussian shaped dynamic polarisability rather than a spatial delta function is a major step in providing a self-consistent description for interparticle de-excitation processes at the limit of small separations. Ion-solid interactions are governed by a range of complex processes the direct experimental observation of which pose their own set of challenges. Here, the authors present a joint experimental and first-principles approach to study and describe the underlying mechanism of electron capture for an ion travelling through layers of graphene with monolayer precision. [ABSTRACT FROM AUTHOR]

Suspended membranes of two-dimensional (2D) materials are of interest for many applications. Much of their characterization relies on scanning probe microscopy (SPM) techniques such as atomic force microscopy (AFM) or scanning tunneling microscopy (STM). Unlike rigid samples, the suspended atomically thin 2D membranes are, however, flexible and do not remain mechanically undisturbed during SPM measurements. Local deformations can occur at the location of the scanning tip and thus result in measurements that misrepresent actual membrane topography and nanomechanical properties. Exact levels of such SPM tip-induced deformations in 2D membranes remain largely unknown, as they are to date only indirectly accessible via dual probe microscope concepts that either are not mechanically independent (e.g., SPM-SPM setups resulting in complicated imaging crosstalk) or suffer from intrinsically limited lateral resolution (e.g., optical far-field techniques as the second probe). Circumventing these shortcomings, we here demonstrate that by coupling an AFM with a scanning electron microscope (SEM) as the second, mechanically independent probe, we can directly and in situ visualize by SEM at high resolution 2D membrane deformations that result from controllable AFM tip manipulations in the nN range. Employing few-layer graphene as model membranes, we discuss the experimental realization of our coupled in situ AFM-SEM approach. [ABSTRACT FROM AUTHOR]

• Fe 2 P catalyst induces electrochemical reduction of N 2 to NH 3 in alkaline medium. • Combination of Fe0 and P sites form active centers at the electrocatalytic interface. • Fe 2 P is characterized by reasonable selectivity with respect to hydrogen evolution. • Fe 2 P also exhibits catalytic properties toward electroreduction of O 2 , NO 3 − and NO 2 −. • The NH 3 product can be detected by voltammetric oxidation at Pt nanoparticles. A catalytic system based on iron phosphide (Fe 2 P) has exhibited electrocatalytic activity toward N 2 -reduction reaction in alkaline medium (0.5 mol dm−3 NaOH). Based on voltammetric stripping-type electroanalytical measurements, Raman spectroscopic and spectrophotometric data, it can be stated that the Fe 2 P catalyst facilitates conversion of N 2 to NH 3 , and the process is fairly selective with respect to the competing hydrogen evolution. A series of diagnostic electrocatalytic experiments (utilizing platinum nanoparticles and HKUST-1) have been proposed and performed to control purity of nitrogen gas and to probe presence of potential contaminants such as ammonia, nitrogen oxo-species and oxygen. On the whole, the results are consistent with the view that the interfacial reduced-iron (Fe0) centers, while existing within the network of P sites, induce activation and reduction of nitrogen, parallel to the water splitting (reduction) to hydrogen. It is apparent from Tafel plots and impedance measurements that mechanism and dynamics of nitrogen reduction depends on the applied electroreduction potential. The catalytic system exhibits certain tolerance with respect to the competitive hydrogen evolution and gives (during electrolysis at -0.4 V vs. RHE) the Faradaic efficiency, namely, the selectivity (molar) efficiency, toward production of NH 3 on the level of 60%. Under such conditions, the NH 3 -yield rate has been found to be equal to 7.5 µmol cm−2 h−1 (21 µmol m−2 s−1). By referring to classic concepts of electrochemical kinetic analysis, the rate constant in heterogeneous units has been found to be on the moderate level of 1-2*10−4 cm s−1 (at -0.4 V). The above mentioned iron-phosphorous active sites, which are generated on surfaces of Fe 2 P particles, have also been demonstrated to exhibit strong catalytic properties during reductions of other electrochemically inert reactants, such as oxygen, nitrites and nitrates. [ABSTRACT FROM AUTHOR]

Many applications of 2D materials require deposition of non‐2D metals and metal‐oxides onto the 2D materials. Little is however known about the mechanisms of such non‐2D/2D interfacing, particularly at the atomic scale. Here, atomically resolved scanning transmission electron microscopy (STEM) is used to follow the entire physical vapor deposition (PVD) cycle of application‐relevant non‐2D In/In2O3 nanostructures on graphene. First, a "quasi‐in‐situ" approach with indium being in situ evaporated onto graphene in oxygen‐/water‐free ultra‐high‐vacuum (UHV) is employed, followed by STEM imaging without vacuum break and then repeated controlled ambient air exposures and reloading into STEM. This allows stepwise monitoring of the oxidation of specific In particles toward In2O3 on graphene. This is then compared with conventional, scalable ex situ In PVD onto graphene in high vacuum (HV) with significant residual oxygen/water traces. The data shows that the process pathway difference of oxygen/water feeding between UHV/ambient and HV fabrication drastically impacts not only non‐2D In/In2O3 phase evolution but also In2O3/graphene out‐of‐plane texture and in‐plane rotational van‐der‐Waals epitaxy. Since non‐2D/2D heterostructures' properties are intimately linked to their structure and since influences like oxygen/water traces are often hard to control in scalable fabrication, this is a key finding for non‐2D/2D integration process design. [ABSTRACT FROM AUTHOR]

Polyoxometalates (POMs) are molecular metal oxide clusters that feature a broad range of structures and functionalities, making them one of the most versatile classes of inorganic molecular materials. They have attracted widespread attention in homogeneous catalysis. Due to the challenges associated with their aggregation, precipitation, and degradation under operational conditions and to extend their scope of applications, various strategies of depositing POMs on heterogeneous substrates have been developed. Recent ground‐breaking developments in the materials chemistry of supported POM composites are summarized and links between molecular‐level understanding of POM‐support interactions and macroscopic effects including new or optimized reactivities, improved stability, and novel function are established. Current limitations and future challenges in studying these complex composite materials are highlighted, and cutting‐edge experimental and theoretical methods that will lead to an improved understanding of synergisms between POM and support material from the molecular through to the nano‐ and micrometer level are discussed. Future development in this fast‐moving field is explored and emerging fields of research in POM heterogenization are identified. [ABSTRACT FROM AUTHOR]

2D SBU, charge separation, hydrogen, mechanism, photocatalysis, Ti-MOF Upon photoexcitation, this unique structure enables efficient charge separation and extraction, displaying a ligand to metal charge transfer mechanism and boosting H SB 2 sb formation. Keywords: 2D SBU; charge separation; hydrogen; mechanism; photocatalysis; Ti-MOF EN 2D SBU charge separation hydrogen mechanism photocatalysis Ti-MOF 1 1 1 08/22/23 20230818 NES 230818 B Hydrogen Evolution Reaction b In article number 2300961, Dominik Eder and co-workers test a visible light responsive titanium-based metal-organic framework (MOF) comprised of 2D secondary building units for the hydrogen evolution reaction. [Extracted from the article]

Graphical abstract Highlights • CS nanoparticles loaded with oxacillin and DNase (CSNP-DNase-Oxa) were fabricated. • CSNP-DNase-Oxa exhibited the best antibiofilm activity in all in-vitro tests. • CSNP-DNase-Oxa reduced the biofilm matrix, thickness and the amount of viable cells. • CSNP-DNase-Oxa showed the highest eradication of clinical isolates biofilms. Abstract Bacterial biofilms play a key role during infections, which are associated with an increased morbidity and mortality. The classical antibiotic therapy cannot eradicate biofilm-related infections because biofilm bacteria display high drug resistance due to biofilm matrix. Thus, novel drug delivery to overcome biofilm resistance and eliminate biofilm-protected bacteria is needed to be developed. In this study, positively charged chitosan nanoparticles (CSNP) loaded with oxacillin (Oxa) and Deoxyribonuclease I (CSNP-DNase-Oxa) were fabricated. The antibiofilm activity was evaluated against Staphylococcus aureus biofilms. Biofilm architecture on silicone surfaces was investigated by scanning electron microscopy (SEM). Confocal laser scanning microscopy (CLSM) was used to examine live/dead organisms within biofilm. CSNP-DNase-Oxa exhibited higher antibiofilm activity than Oxa-loaded nanoparticles without DNase (CSNP-Oxa) and free Oxa (Oxa and Oxa + DNase) at each concentration in all in-vitro tests. CSNP-DNase-Oxa inhibited biofilm formation in-vitro and eradicated mature biofilm effectively. CSNP-DNase-Oxa could disrupt the biofilm formation through degradation of eDNA, reduced biofilm thickness and the amount of viable cells on silicone. Repeated treatment with CSNP-DNase-Oxa for two days resulted in 98.4% biofilm reduction. Moreover, CSNP-DNase-Oxa was not only able to affect the biofilm of a standard S. aureus strain, but also showed the highest eradication of biofilms of clinical isolates compared with control groups. These results suggest the potential applicability of NPs for the treatment of biofilm-related infections and provide a platform for designing novel drug delivery with more functions. [ABSTRACT FROM AUTHOR]

In the present work, the channels of metallicity-sorted metallic single-walled carbon nanotubes (SWCNTs) have been filled with silver chloride. The data of high-resolution scanning transmission electron microscopy proved the filling of the nanotube channels and formation of few-atom-thick crystals of silver chloride. The electronic properties of the filled SWCNTs were investigated by Raman spectroscopy, X-ray photoelectron spectroscopy, and ultraviolet photoelectron spectroscopy. Our results indicate the p-doping of nanotubes by silver chloride accompanied by the charge transfer from the nanotubes to the encapsulated compound and the downshift of the Fermi level by 0.36 eV. The calculated number of transferred electrons per nanotube carbon atom and the charge transfer density per nanotube length amounted to 0.0024 e− per carbon and 0.0406 e−/Å, respectively. It was found that the band gap opens up in the band structure of the filled SWCNTs resulting in their transition from metallic into a semiconducting state. This work reveals a direct influence of the incorporated silver chloride on the electronic properties of metallicity-sorted metallic SWCNTs and demonstrates the potential of precise Fermi level engineering of SWCNTs by filling their channels and achieving high doping levels, thus providing a platform for designing next-generation nanoelectronic devices. [ABSTRACT FROM AUTHOR]

This work demonstrates the fabrication of a high-efficiency, hole-conductor-free, solid-state perovskite solar cell with TiO 2 -nanorod arrays (NRAs) as photoanodes and commercial carbon ink as counter-electrodes. TiO 2 -NRA films of various thicknesses were deposited on FTO electrodes through hydrothermal method for different reaction durations. The effect of the thickness of TiO 2 -NRA films on device performance was investigated in detail. The TiO 2 NRAs/CH 3 NH 3 PbI 3 /C devices based on 688 nm-thick TiO 2 -NRA films exhibited the optimal performance and power conversion efficiency (PCE) of as high as 8.56%. This value is comparable with the PCE of the recently reported TiO 2 NRA/Perovskite/HTM/Au solar cell. [ABSTRACT FROM AUTHOR]

Abstract: Nanocarbon–metal oxide hybrids are among the most promising functional materials in many cutting‐edge environmental and energy applications where efficient charge separation and extraction are keys to success. The next level of hybrid structures will be achieved once one learns how to control and tune charge/energy transfer processes at the interfaces. However, little is yet known about the nature and extent of these interfacial dynamics in nanocarbon hybrids. Here a model is designed in which ultrathin dielectric layers (Al2O3, ZrO2) between the hybrid's components (ZnO, TiO2) and carbon nanotubes allow for evaluating and tuning of interfacial charge transfer over an unusually long distance of at least 50 nm. Surprisingly, the transfer efficiency correlates linearly with the barrier layer thickness, indicating that electron conduction through the barrier layer constitutes the rate‐limiting step. It is also demonstrated that the charge transfer efficiency can be tuned by the type of interlayer and its degree of crystallinity, thus controlling the hybrid's performance in the photocatalytic production of hydrogen. It is believed that this model system will help to understand and decipher the fundamentals regarding interfacial charge and energy transfer in nanocarbon hybrids with the aim to further advance these hybrid structures for a wide range of energy applications. [ABSTRACT FROM AUTHOR]

The organic–inorganic perovskite compound (CH 3 NH 3 ) 3 Bi 2 I 9 (MBI) has lower toxicity and higher stability than lead-based perovskite. In this work, we fabricated MBI perovskite-based solar cells (PSCs) through a two-step sequential-solution process by using rutile TiO 2 nanorod array (NRA) films as the electron transporting layer (ETL) for the first time. The thickness, roughness, and crystal structure of the rutile TiO 2 NRAs prepared by hydrothermal method with different reaction times were thoroughly characterized and correlated with the photovoltaic performance of PSCs. Results of morphological and structural analyses, as well as time-resolved photoluminescence studies, indicated the effect of TiO 2 NRA film thickness on the carrier recombination and photovoltaic performance of MBI-based PSCs. The MBI-based device was also stable in an environment with >50% humidity for more than 67 days. [ABSTRACT FROM AUTHOR]

Hierarchical hollow microspheres (HHMSs) constitute a very popular class of materials for use as drug-delivery carriers, photocatalysts and electrode materials in batteries, owing to their large, porous surface area and mechanical integrity during intercalation reactions. Here, we used a template- and additive-free hydrothermal route to prepare an unusually shaped SnO2 material that comprises a hollow spherical morphology with uniform diameters and very thin petal-like nano-sheets grown perpendicularly on the sphere's surface, resembling a “chestnut cupule”. We thoroughly investigated the formation mechanism by 119Sn Mössbauer spectroscopy, powder X-ray diffraction and X-ray photoelectron spectroscopy. Key to this process is the ultrasonic pre-treatment of an aqueous SnCl2 solution, followed by Ostwald “inside-out” ripening upon hydrothermal processing. This unique morphology has greatly improved the storage capacity and cycling performance of SnO2 as an anode material for lithium and sodium ion batteries compared with conventional SnO2 materials. [ABSTRACT FROM AUTHOR]

Defects at the surface and grain boundaries of three-dimensional (3D) organic-inorganic metal halide perovskite films lead to the non-radiative recombination of charge carriers and accelerate perovskite decomposition. In turn, this deteriorates the power conversion efficiency (PCE) and stability of perovskite solar cells (PSCs). Herein, p -methylphenylmethylammonium iodide (p -MePMAI) was reacted with a 3D perovskite to in - situ form a two-dimensional (2D) perovskite upper layer. This upper layer passivated the surface and grain boundary defects of the 3D perovskite film, improving its surface hydrophobicity. As a result, a carbon counter electrode (CE)-based 2D/3D PSC achieved a maximum PCE of up to 15.63%, which was much higher than that of an unmodified 3D MAPbI 3 PSC (12.16%). Moreover, the unencapsulated 2D/3D device maintained 80% of its initial PCE after exposure to air for 700 h with a relative humidity (RH) of 40 ± 5%. This research opens a new pathway for the successful construction of stable and efficient 2D/3D PSCs with organic ammonium salts. [Display omitted] • The p -MePMAI treatment can effectively passivate surface/interface defects and improve the performance of PSCs. • The champion device has a PCE of 15.63% with J sc of 22.15 mA cm−2, V oc of 1.101 V, and FF of 0.64. • The 2D hybrid passivation layer can further increase the stability by preventing contact of water with the 3D perovskite. [ABSTRACT FROM AUTHOR]

A series of five decavanadates (V 10) using a simple, one-pot synthesis, adhering to the model template: transition metal ion – decavanadate – ligands :(H nicotinamide) 2 {[Co(H 2 O) 3 (nicotinamide) 2 ] 2 [ μ -V 10 O 28 ]}.6H 2 O (1) , {[Co(H 2 O) 4 (isonicotinamide) 2 ] 3 }V 10 O 28 ·4H 2 O (2) , {[Co(H 2 O) 4 ] 2 [Co(H 2 O) 2 (μ - pyrazinamide) 2 ][ μ -V 10 O 28 ]}·4H 2 O (3) {[Co(H 2 O) 4 (μ - pyrazinamide)] 3.V 10 O 28 }·4H 2 O (4) , and (NH 4) 2 {[Ni(H 2 O) 4 (2 -hydroxyethylpyridine)] 2 }V 10 O 28 ·2H 2 O (5) was synthesized. X-ray analysis reveals that 1 and 3 are decavanadato complexes, while 2 , 4 and 5 are decavanadate complex salts. Moreover, 3 is the first example of a polymeric decavanadato complex, employing direct coordination with the metal center and the organic ligand, in toto. From the solution studies using 51V NMR spectroscopy, it was decoded that 1 and 3 stay stable in the model buffer solution and aqueous media. Binding to model proteins, cytotoxicity and water oxidation catalysis (WOC) was studied primarily for 1 and 3 and concluded that neither 1 nor 3 have an interaction with the model proteins thaumatin, lysozyme and proteinase K, because of the presence of the organic ligands in the Co(II) center, any further interplay with the proteins was blocked. Cytotoxicity studies reveal that 1 is 40% less toxic (0.05 m M) and 26% less toxic (0.1 m M) than the uncoordinated V 10 with human cell lines A549 and HeLa respectively. In WOC, 1 performed superior activity, by evolving 143.37 nmol of O 2 which is 700% (9-fold) increase than the uncoordinated V 10. SYNOPSIS Coordination of decavanadate anion to cobalt(II) complex cations with organic ligands enhanced its stability in solutions allowing in-depth study of synthesis conditions, water oxidation catalysis reaction, cytotoxicity and protein binding. [Display omitted] • Five new decavanadates with transition metal complex cations were prepared. • The coordination of decavanadate to cobalt(II) stabilizes it in solution. • Free decavanadate is more toxic than a coordinated for HeLa and A549 cell lines. • Coordination by cobalt(II) center with isonicotinamide ligand increases WOC activity. [ABSTRACT FROM AUTHOR]

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. As a result, the development of long-term and effective POP removal techniques is critical. In water, adsorption removal and photocatalytic degradation of POPs have been identified as energy and cost-efficient solutions. Both technologies have received a lot of attention for their efforts to treat the world's wastewater. Photocatalytic removal of POPs is a promising, effective, and long-lasting method, while adsorption removal of persistent POPs represents a simple, practical method, particularly in decentralized systems and isolated areas. It is critical to develop new adsorbents/photocatalysts with the desired structure, tunable chemistry, and maximum adsorption sites for highly efficient removal of POPs. As a class of recently created multifunctional porous materials, Metal-organic frameworks (MOFs) offer tremendous prospects in adsorptive removal and photocatalytic degradation of POPs for water remediation. This review defines POPs and discusses current research on adsorptive and photocatalytic POP removal using emerging MOFs for each type of POPs. [Display omitted] • Well-organized categorizing of Persistent Organic Pollutants (POPs). • Comprehensive exploring of photocatalytic and adsorption techniques for POPs removal from wastewater by MOFs. • Investigation of removal mechanisms, challenges, and strategies to improve performance of MOFs. • Covering and discussing the most recent advances and achievements in the field of POP removal by MOFs. [ABSTRACT FROM AUTHOR]

We demonstrate a unique route towards hierarchical assemblies of mesoporous TiO 2 and CNT/TiO 2 photocatalysts by a combination of electrospinning and sol–gel methods. The resulting materials exhibit a mesoporous network of highly crystalline, well-connected inorganic nanocrystals with an order of magnitude higher photocatalytic activity than individualised TiO 2 nanoparticles. The in-situ combination of small amounts of MWCNTs with TiO 2 to form an electrospun CNT/TiO 2 hybrid further enhanced the oxide photoactivity considerably, reaching hydrogen evolution rates of 1218 μmol/h in water splitting in the presence of sacrificial reagents under UV irradiation. We also discuss the effect of oxygen vacancies on the oxide crystallisation and phase transformation. These vacancies lead to inter-bandgap states and a lower flat band potential that facilitates the photocatalytic process. [ABSTRACT FROM AUTHOR]

An effective biomimetic method for preparation of hydroxyapatite/graphene oxide (HA/GO) hybrid coating on AZ91 magnesium alloy was firstly proposed. AZ91 Mg alloy was first dip coated by GO, which was further used as matrix substrate for biomimetic mineralization of hydroxyapatite (HA) in modified simulated body fluid (m-SBF). It has been found that GO greatly promotes nucleation and crystallization for rapid HA growth, forming uniform and dense HA/GO hybrid coating comprised by flake-like HA crystals with high Ca/P ratio (1.65). Meanwhile, the as-formed HA/GO bio-coating could dramatically improve the corrosion resistance of Mg alloys. The corrosion current density of treated Mg alloys was decreased by one order of magnitude as compared to untreated one. Furthermore the effects of various experimental parameters toward the growth of the HA/GO coating on Mg alloys were also investigated. [ABSTRACT FROM AUTHOR]

Abstract: Hybridizing carbon nanotubes with complex inorganic nanostructures provides a new route to designing next-generation photocatalysts. These hybrids utilize charge transfer processes through the interface, which reduce the electron–hole recombination rate in the photocatalyst. This work presents the first complex CNT hybrid, using titanium-silicate (TS-1), with dramatically improved photocatalytic activity for the degradation of organic compounds compared with the corresponding nanocomposite and the individual components. [ABSTRACT FROM AUTHOR]

Scanning electron microscopy (SEM) and profilometry of the crater morphology and ablation efficiency upon femtosecond laser ablation of Au-coated Ni targets in various fluids revealed a pronounced dependence on the ablation medium. For ethanol, a sufficient ablation efficiency was obtained, whereas for 2-butanol a higher efficiency indicated stronger laser–target interaction. Hierarchical features in the crater periphery pointed to asymmetrical energy deposition or a residual effect of the Coulomb-explosion-initiating ablation. Significant beam deviation in 2-butanol caused maximum multiple scattering at the crater bottom. The highest values of microstrain and increased grain size, obtained from Williamson–Hall plots, indicated the superposition of mechanical stress, defect formation and propagation of fatigue cracks in the crater circumference. For n-hexane, deposition of frozen droplets in the outer crater region suggested a femtosecond-laser-induced phase explosion. A maximum ablation depth occurred in water, likely due to its high cooling efficiency. Grazing incidence micro X-ray diffraction (GIXRD) of the used target showed residual carbon and partial surface oxidation. The produced nanoparticle colloids were examined by multiangle dynamic light scattering (DLS), employing larger scattering angles for higher sensitivity toward smaller nanoparticles. The smallest nanoparticles were obtained in 2-butanol and ethanol. In n-hexane, floating carbon flakes originated from femtosecond-laser-induced solvent decomposition. [ABSTRACT FROM AUTHOR]

• We unravelled the impact of ligand composition on photocatalytic hydrogen evolution over Ti-based MOFs. • MIL-125-Ti outperforms NH2-containing counterparts by up to 38 times in methanol • Photoluminescence spectroscopy shows effective hole scavenging by methanol in MIL-125-Ti. • Triethanolamine leads to corrosion of the MOFs within the first few hours through partial ligand exchange. • We propose three mechanisms for photocatalytic hydrogen evolution for both single-ligand and mixed-ligand MOFs. We synthesized a series of isostructural MIL-125-Ti with various terephthalic: amino-terephthalic acid ratios and evaluated their photostability and performance for photocatalytic hydrogen evolution in aqueous solutions with different hole scavengers. We demonstrate that the commonly used triethanolamine corroded the MOFs under photocatalytic conditions, in contrast to methanol. The combination of MIL-125-Ti and methanol outperformed the photocatalytic activity of NH 2 -MIL-125-Ti by 45 times under broad UV irradiation. Photoluminescence spectroscopy under simulated photocatalytic conditions and in solid-state as well as time-resolved emission studies reveal that the holes residing in the metal-oxo cluster can be effectively scavenged by methanol, leading to high HER activity, while the holes residing in the NH 2 -groups in the ligand favour charge recombination and are thus detrimental to the photocatalytic performance. The mixed-ligand MOFs follow a dual-excitation pathway, introducing new states and transitions. These results are expected to advance our understanding of MOF-based photocatalysis. [ABSTRACT FROM AUTHOR]

Single-crystalline sillenite-type bismuth titanate nanowires with photocatalytic properties have been synthesized viaa simple solution-phase synthesis route. [ABSTRACT FROM AUTHOR]

Methylammonium bismuth iodide ((CH 3 NH 3) 3 Bi 2 I 9 , MBI) is a promising alternative to perovskite solar cells (PSCs) due to its air stability and low-toxicity. Herein, a two-stage electric-field-assisted reactive deposition method has been introduced to prepare MBI films for the first time. PSCs based on MBI films were fabricated and characterized. The influences of electric parameters (applied voltage mode, pulse and time, etc.) on the morphology and crystal structure of MBI film correlated with the photovoltaic performance of PSCs have also been investigated systematically in detail. Through adjusting the voltage mode, crystal growth can be completely controlled, leading to a compact MBI film with large grain size. Moreover, the MBI film prepared by electrochemical deposition required no annealing. This work determined that the optimal performance of PSCs is based on the MBI film deposited by square-wave (AC) voltage mode (−7.3 V/+1 V, 5 Hz, 5 min). All devices exhibited long-term stability in ambient air (humidity of >50%) for more than 300 h. This study will inspire further research on the application of electrochemical deposition technique for other lead-free PSCs. Image 1 • A two-stage electric-field-assisted reactive deposition method has been introduced to prepare (CH 3 NH 3) 3 Bi 2 I 9 films for the first time. • The influences of electric parameters on MBI film morphology and crystal structure correlating with the photovoltaic performance of PSCs have been investigated systematically. • The proposed electrochemical deposition method is facile, controllable, and repeatable, and significant to the commercial production of perovskite. • The proposed electrochemical deposition involves an annealing-free fabrication, thus simplifying the process and promoting production efficiency. [ABSTRACT FROM AUTHOR]

Single‐walled carbon nanotubes (SWCNTs) with a mean diameter of 1.4 nm are filled with rubidium iodide. The filling of nanotubes is proved by high‐resolution scanning transmission electron microscopy. The chemical composition of the filler is confirmed by X‐ray photoelectron spectroscopy (XPS). The electronic properties of the filled SWCNTs are studied by XPS and Raman spectroscopy. The encapsulated salt leads to n‐doping of nanotubes. The detailed multifrequency Raman spectroscopy investigation of the alteration of Raman modes of SWCNTs upon filling is conducted. The doping‐induced changes in the radial breathing mode and G‐band are revealed. It is found that these changes differ for the metallic and semiconducting SWCNTs. The obtained data and revealed trends are expected to be helpful for forthcoming studies to interpret the observed changes in Raman spectra of filled metallic and semiconducting SWCNTs. [ABSTRACT FROM AUTHOR]

This study aims to investigate the physical and chemical characterization of six fly ash samples obtained from different municipal solid waste incinerators (MSWIs), namely grate furnaces, rotary kiln, and fluidized bed reactor, to determine their potential for CO2 and thermochemical energy storage (TCES). Representative samples were characterized via simultaneous thermal analysis (STA) in different atmospheres, i.e., N2, air, H2O, CO2, and H2O/CO2, to identify fly ash samples that can meet the minimum requirements, i.e., charging, discharging, and cycling stability, for its consideration as TCES and CO2-storage materials and to determine their energy contents. Furthermore, other techniques, such as inductively coupled plasma optical emission spectroscopy, X-ray fluorescence (XRF) spectrometry, X-ray diffraction (XRD), scanning electron microscopy, leachability tests, specific surface area measurement based on the Brunauer–Emmett–Teller method, and particle-size distribution measurement, were performed. XRF analysis showed that calcium oxide is one of the main components in fly ash, which is a potentially suitable component for TCES systems. XRD results revealed information regarding the crystal structure and phases of various elements, including that of Ca. The STA measurements showed that the samples can store thermal heat with energy contents of 50–394 kJ/kg (charging step). For one fly ash sample obtained from a grate furnace, the release of the stored thermal heat under the selected experimental conditions (discharging step) was demonstrated. The cycling stability tests were conducted thrice, and they were successful for the selected sample. One fly ash sample could store CO2 with a storage capacity of 27 kg CO2/ton based on results obtained under the selected experimental conditions in STA. Samples from rotary kiln and fluidized bed were heated up to 1150 °C in an N2 atmosphere, resulting in complete melting of samples in crucibles; however, other samples obtained from grate furnaces formed compacted powders after undergoing the same thermal treatment in STA. Samples from different grate furnaces showed similarities in their chemical and physical characterization. The leachability test according to the standard (EN 12457-4 (2002)) using water in a ratio of 10 L/S and showed that the leachate of heavy metals is below the maximum permissible values for nonhazardous materials (except for Pb), excluding the fly ash sample obtained using fluidized bed technology. The leachate contents of Cd and Mn in the fly ash samples obtained from the rotary kiln were higher than those in other samples. Characterization performed herein helped in determining the suitable fly ash samples that can be considered as potential CO2-storage and TCES materials. [ABSTRACT FROM AUTHOR]

Crystalline Ni/Au bimetallic oxide nanoparticles with various forms of crystallographic systems and defects were generated by femtosecond laser ablation of nickel–gold target in alcoholic solvents. The nature of the liquid can influence the chemical composition, stability, and size distribution of laser-synthesized nanoparticles. In ethanol, bimodal crystalline bimetallic Ni/Au oxide nanoparticles with median size of 15 nm were synthesized. The laser ablation of Ni/Au target in isopropanol and butanol led to nearly monomodal size distribution with median size of 10 and 13 nm, respectively. High-resolution transmission electron microscopy of Ni/Au oxide nanoparticles in butanol, revealed a graphitic shell of a few atomic layers. In this context, two suggested mechanisms were considered. First of all, the high photon intensity of femtosecond laser pulses can induce direct photolysis of liquid media. Secondly, the formation of supercritical temperature solvent due to the interaction of solvent with molten metal layer at liquid–metal interface can trigger pyrolysis of solvent. These mechanisms can contribute to butanol decomposition and encapsulation of Ni/Au oxide bimetallic nanoparticles with graphite shell. Graphite shell can create a better colloidal stability by preventing nanoparticles from further growth and agglomeration. [ABSTRACT FROM AUTHOR]

In this work, we employed a step-by-step sol-gel process to controllably deposit ultra-thin layers of Si O 2 on anatase nanoparticles in the range between 0 and 1 nm. The deposition was confirmed by TEM, EDX, and ATR-FTIR (e.g., Ti-O-Si band at 960 c m - 1 ). Zeta potential measurements unravelled a continuous change in surface charge density with increasing silica shell thickness. The photocatalysts were evaluated towards adsorption and degradation of positively-charged and negatively-charged dyes (methylene blue, methyl orange) under UV illumination. The growth mechanism follows the Stranski–Krastanov model with three thickness regimes: (a) Flat islands (first step), (b) mono/bilayers (second/third step), and (c) regular thick films (fourth/fifth step). The results suggest different rate limiting processes for these regimes: (a) For the thinnest scenario, acidic triple-phase boundaries (TPBs) increase the activity for both dyes with their accessibility being the rate limiting step; (b) for continuous mono/bilayers, dye adsorption on the negatively-charged S i O 2 shells becomes the rate liming step, which leads to a stark increase in activity for the positively-charged MB and a decrease for MO; (c) for thicker shells, the activity decreases for both dyes and is limited by the charge transport through the isolating shells. [ABSTRACT FROM AUTHOR]

We have investigated the electronic properties of single-walled carbon nanotubes (SWCNTs) filled with lead chloride, lead bromide (PbBr2) and lead iodide (PbI2). The filling of SWCNTs and formation of encapsulated one-dimensional nanocrystals of the salts were directly confirmed by high-resolution scanning transmission electron microscopy. The chemical composition of the encapsulated nanocrystals was proven by X-ray photoelectron spectroscopy (XPS). The electronic properties of the filled SWCNTs were characterized by Raman spectroscopy and XPS. All the three lead halogenides result in p-doping of SWCNTs and, consequently, there is a downshift of the SWCNTs' Fermi level due to the charge transfer towards the salts. The effect is stronger with metallic than semiconducting nanotubes. The efficiency of doping depends on the type of lead halogenide. The doping effect is the strongest for PbI2 and the weakest for PbBr2. [ABSTRACT FROM AUTHOR]

Pure and Nb‐doped TiO2 photocatalysts with highly ordered alternating gyroid architecture and well‐controllable mesopore size of 15 nm via co‐assembly of a poly(isoprene)‐block‐poly(styrene)‐block‐poly(ethylene oxide) block copolymer are synthesized. A combined effort by electron microscopy, X‐ray scattering, photoluminescence, X‐ray photoelectron spectroscopy, Raman spectroscopy, and density functional theory simulations reveals that the addition of small amounts of Nb results in the substitution of Ti4+ with isolated Nb5+ species that introduces inter‐bandgap states, while at high concentrations, Nb prefers to cluster forming shallow trap states within the conduction band minimum of TiO2. The gyroidal photocatalysts are remarkably active toward hydrogen evolution under UV and visible light due to the open 3D network, where large mesopores ensure efficient pore diffusion and high photon harvesting. The gyroids yield unprecedented high evolution rates beyond 1000 µmol h−1 (per 10 mg catalyst), outperforming even the benchmark P25‐TiO2 more than fivefold. Under UV light, the Nb‐doping reduces the activity due to the introduction of charge recombination centers, while the activity in the visible triple upon incorporation is owed to a more efficient absorption due to inter‐bandgap states. This unique pore architecture may further offer hitherto undiscovered optical benefits to photocatalysis, related to chiral and metamaterial‐like behavior, which will stimulate further studies focusing on novel light–matter interactions. Superior hydrogen evolution is achieved by using highly ordered mesoporous pure and Nb‐doped TiO2 with alternating gyroid architecture due to their large pores and 3D connectivity. The incorporation of Nb5+ has different effects on visible and UV‐based photocatalysis. [ABSTRACT FROM AUTHOR]

In this paper, we have performed the filling of single‐walled carbon nanotubes (SWCNTs) with mean diameters of 1.4 and 1.9 nm synthesized by the arc‐discharge and chemical vapor deposition (CVD) methods, respectively, with silver chloride. The doping effect of the encapsulated compound on SWCNTs is studied by Raman spectroscopy and X‐ray photoelectron spectroscopy. It is shown that the filling of nanotubes with silver chloride leads to p‐doping of SWCNTs accompanied by charge transfer from the SWCNTs to the salt and downshift of their Fermi level. It is found that the filling of SWCNTs synthesized by different methods results in different doping levels of nanotubes. The arc‐discharge 1.4 nm‐diameter SWCNTs have larger doping level than CVD 1.9 nm‐diameter nanotubes. The obtained information about the influence of the filler on the electronic properties of SWCNTs synthesized by different methods is elemental for applications of nanotubes in nanoelectronic devices. Kharlamova et al. perform the filling of single‐walled carbon nanotubes (SWCNTs) synthesized by the arc‐discharge and chemical vapor deposition methods with silver chloride. The electronic properties of the filled nanotubes are characterized by Raman spectroscopy and X‐ray photoelectron spectoscopy. The authors reveal different doping levels of SWCNTs synthesized by the different methods. [ABSTRACT FROM AUTHOR]