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Recently, fluoride ceramics have gained much interest because of their low permittivities and high Q×f values at microwave frequencies, coupled with relatively low sintering temperatures. In this paper, we have explored the effects of the particle-size and O contamination of LiF raw material, sintering/annealing atmosphere on the mechanosynthesis, structural stability, and microwave dielectric properties of BaLiF 3 ceramic. Using a fine LiF raw material would facilitate the mechanical synthesis of BaLiF 3 , being densified at lower temperatures than the coarse one. A high concentration of oxygen contamination in LiF raw material and partial pressure of O 2 in the sintering atmosphere would lead to the formation of BaF 2 due to the instability of the fluoride perovskite with an increase in the concentration of F-vacancies caused by the partial oxidization during the sintering at high temperature (850 °C/2h). The oxidization of fluoride perovskite preferably occurs at the surface and grain boundaries via O diffusion, which reduces the Q×f value from 83175 to 70228 GHz with little change in ε r (∼11) and τ f values (∼-71 ppm/°C). [ABSTRACT FROM AUTHOR]

The performance and stability of perovskite solar cells rely crucially on the purity of their active perovskite phase. While the two‐step method has emerged as a well‐known technique for fabricating high‐performance cells, it suffers from significant PbI2 phase impurities at the buried layer due to inefficient diffusion of cationic molecules into the preprepared PbI2 layer. Herein, a simple yet highly effective method is presented to boost phase purity within the buried layer by introducing formamidinium iodide (FAI) seed molecules into the underlying PbI2 layer. X‐Ray diffraction analysis result reveals that this process significantly reduces the PbI2 phase and enhances the purity of the perovskite's phase. It is also observed that this technique can produce perovskite layer with a remarkably smooth surface structure and large interconnected crystal grains, forming a continuous layer. These characteristics are subjected to further enhancement when hexamethylenetetramine molecules are concurrently introduced with FAI into the PbI2 layer. Solar cells fabricated using this method, with an active area of 0.1 cm2, achieve a remarkable power conversion efficiency of up to 24.52% with Voc as high as 1.18 V, representing a substantial improvement over cells produced using the standard two‐step method, which attains only 22.18% efficiency. With its simple yet impactful approach, the present method should find widespread adoption in the production of high‐performance perovskite solar cells. [ABSTRACT FROM AUTHOR]

Abstract REBCO has been used extensively as coated conductors applied to superconducting magnets due to its exceptional superconducting properties. As a REBCO superconductor, YbBa2Cu3O7−y (Yb123) has a low melting temperature, making it suitable for use as an intermediate medium connector while preparing the superconducting joint. However, there is still uncertainty about the formation mechanism of Yb123 and the synthesis of this superconductor has not been fully understood. Therefore, this study systematically investigated the phase transformation process of Yb123 during heat treatment in flowing oxygen. The results indicated that Yb123 sample with the highest phase purity could be obtained by annealing at 927 °C or 937 °C but not in between, respectively. Furthermore, a quantitative phase analysis revealed that the sample annealed at 937 °C had a phase purity greater than 80 wt%. Additionally, a strong c-axis texture was observed in the bulk Yb123 superconductor prepared at 937 °C. Meanwhile, the superconducting results revealed that the bulk sample’s Tc was 89.9 K, and its self-field critical current densities at 4.2 K and 77 K were 1.3 × 105 A/cm2 and 5.0 × 103 A/cm2, respectively. Based on the results mentioned above, the phase transformation process and formation mechanism of Yb123 in flowing oxygen were elaborated.

TiO2(B) is a promising anode material for lithium‐ion batteries (LIBs) due to its fast lithiation/delithiation kinetics, however, its thermodynamic metastable nature makes it difficult to synthesize pure phase, which significantly affects its lithium storage capability. Herein, the structural evolution from precursor to TiO2(B) is systematically investigated and it is revealed that the formation of high‐purity monoclinic HTO (hydrogen titanate) precursor is the key to preparing TiO2(B) with high purity, which can be achieved via tailored‐design the solvent structures of Ti4+ in the precursor solution. Glycolic acid (GA) is favorable for the synthesis of high‐purity HTO, benefiting from its simplest spatial structure and coplanar carboxyl and hydroxyl groups for Ti4+ coordination, further leading to the formation of TiO2(B) with a high phase purity of 98.83% that exhibits excellent rate capability (80.5% capacity retention with current densities increased from 1 to 30 C), thus making it a promising candidate for simultaneous energy and power density LIBs anode. [ABSTRACT FROM AUTHOR]

REBCO has been used extensively as coated conductors applied to superconducting magnets due to its exceptional superconducting properties. As a REBCO superconductor, YbBa2Cu3O7−y (Yb123) has a low melting temperature, making it suitable for use as an intermediate medium connector while preparing the superconducting joint. However, there is still uncertainty about the formation mechanism of Yb123 and the synthesis of this superconductor has not been fully understood. Therefore, this study systematically investigated the phase transformation process of Yb123 during heat treatment in flowing oxygen. The results indicated that Yb123 sample with the highest phase purity could be obtained by annealing at 927 °C or 937 °C but not in between, respectively. Furthermore, a quantitative phase analysis revealed that the sample annealed at 937 °C had a phase purity greater than 80 wt%. Additionally, a strong c-axis texture was observed in the bulk Yb123 superconductor prepared at 937 °C. Meanwhile, the superconducting results revealed that the bulk sample's Tc was 89.9 K, and its self-field critical current densities at 4.2 K and 77 K were 1.3 × 105 A/cm2 and 5.0 × 103 A/cm2, respectively. Based on the results mentioned above, the phase transformation process and formation mechanism of Yb123 in flowing oxygen were elaborated. [ABSTRACT FROM AUTHOR]

Bronze phase titanium dioxide (TiO2(B)) could be a promising high-power anode for lithium ion battery. However, TiO2(B) is a metastable material, so the as-synthesized samples are inevitably accompanied by the existence of anatase phases. It has been found that the TiO2(B)'s purity is positively correlated with its electrochemical performance. Herein, we have established an accurate quantification of the TiO2(B)/anatase ratio, by figuring out the function between the purity of TiO2(B) phase in the high purity range and its Raman spectra features in combination of the calibration by the synchrotron radiation X-ray diffraction (XRD). Compared with the time-consuming electrochemical method, the rapid, sensitive and non-destructive features of Raman spectroscopy have made it a promising candidate for determining the purity of TiO2(B). Further, the correlations developed in this work should be instructive in synthesizing pure TiO2(B) and furthermore optimizing its electrochemical charge storage properties.

α‐Alumina is a non‐porous metal oxide with applications in ceramics and catalysis. Introducing pores into this material to create catalytically relevant surface area is challenging due to phase transitions over a wide temperature range. Current synthesis strategies involve hard templates such as synthetic polymers, e. g. polymethylmethacrylate (PMMA). Here, we compare cellulose and carbonized glucose as low‐cost and natural alternative templates for high surface area α‐alumina with a two‐step heating method. Quantitative XRD was used to methodically investigate alumina phase purity. Increasing the template size in the range of 220–1000 nm improved α‐alumina purity from 75 to 98 %, while maintaining high surface areas (21–29 m2 g−1). Phase purity increases substantially by prolonging the calcination time. The synthesized high surface area α‐alumina was studied as support for silver catalysts in the epoxidation of ethylene and allowed high silver loadings. Ethylene oxide selectivity increased with enhanced α‐alumina phase purity. Our 30 wt % silver catalyst on pure high surface area α‐alumina did not show loss in selectivity compared to a 15 wt % silver catalyst on commercial non‐porous α‐alumina. This shows the potential of carbohydrate templates, the importance of templating parameters and the benefits of pure high surface area α‐alumina as support for silver catalysts. [ABSTRACT FROM AUTHOR]

Tranexamic acid (TNA) is an anti‐fibrinolytic hemostatic drug widely used in various medical treatments. Six new salts and five cocrystals of TNA are reported here and the crystal structures of the obtained multicomponent compounds were determined using single‐crystal X‐ray diffraction (SC‐XRD) techniques. TNA formed salts with coformers maleic acid (MEA), nicotinic acid, dl‐mandelic acid and saccharin. Salt formation with MEA resulted in three different solid forms, namely TNA–MEA (1:1), TNA–MEA (2:1) and TNA–MEA–H2O (1:1:1). All synthesized TNA salt structures were crystallized as anhydrous except for TNA–MEA–H2O (1:1:1). TNA formed cocrystals with phenolic coformers such as catechol (CAT), resorcinol, hydroquinone, pyrogallol (PRG) and phloroglucinol. All cocrystal structures crystallized as hydrates except for TNA–PRG (1:1). The detailed structural investigation using SC‐XRD revealed the presence of robust N—H...O and O—H...O hydrogen bonds in TNA salts and cocrystals. In TNA cocrystals, except for TNA–CAT–H2O (1:1:1), the coformer molecules interact with TNA molecules via bridged water molecules. In all the salt structures, TNA exists as cations, in which both carboxylic and amino groups are protonated (–COOH and –NH3+), while in cocrystals TNA exists as zwitterions with total charge zero. All synthesized multicomponent compounds were further characterized by differential scanning calorimetric, thermogravimetric and Fourier transform infrared analyses, and the formation of new multicomponent compounds were assessed based on the melting temperatures, percentage weight loss and stretching frequencies, respectively, corresponding to TNA/coformer molecules. A powder X‐ray diffraction study confirmed the bulk purity of the synthesized crystalline multicomponent compounds. [ABSTRACT FROM AUTHOR]

The rapid reaction between lead iodide (PbI 2 ) and formamidinium iodide (FAI) complicates the fabrication of high-quality formamidinium lead iodide (FAPbI 3 ) films. Conventional methods, such as using nonvolatile small molecular additives to slow the reaction, often result in buried interfacial voids and molecule diffusion, compromising the devices' operational stability. In this study, we introduced a molecular "thruster"-a hypervalent iodine (III) compound with three carbonyl groups and a C - -I + bond-that possesses coordination and dissociation abilities, enabling programed modulation of perovskite-film growth kinetics. Initially, the three carbonyl groups coordinate with PbI 2 to slow the reaction between FAI and PbI 2 , preventing δ-phase formation. As temperature rises, the C - -I + bond dissociates, promoting perovskite growth and the dissociated product iodobenzene will promote solvent volatilization, thus avoiding buried interfacial voids. Another product, a carbene compound with eight lone pair electrons sufficiently passivate the undercoordinated Pb 2+ defects and anchors at grain boundaries without diffusion. Consequently, the resultant FAPbI 3 film displays high-quality with enhanced phase purity, compact morphology, and reduced defects. Evidently, 0.062- and 1.004-cm 2 pero-SCs achieve power conversion efficiencies (PCEs) of up to 26.06 % (25.79 % certified) and 24.65 %, respectively. This approach also controls perovskite-film growth on plastic substrates, resulting in flexible pero-SCs with an impressive PCE of 25.12 %., (© 2024 Wiley-VCH GmbH.)

This article evaluates the impact of the addition of zinc (Zn) and magnesium (Mg) on the structural, morphological, and antibacterial characteristics of β-tricalcium phosphates (hereafter called Zn/Mg-βTCP) prepared using the microwave (MW) assisted wet precipitation method in which the Ca deficient apatite [Ca9-(x+y)MgxZny(HPO4)(PO4)5 (OH)] was calcined for 2 h at 1000 °C. The prepared samples were characterized using XRD, FTIR, and FESEM measurements. The XRD patterns of the samples showed a steady decrease in the lattice parameters with an increase in Mg2+ and Zn2+ content. The FESEM images of the samples disclosed the morphological changes due to the Mg2+/Zn2+ co-doping. The inclusion of Mg2+ and Zn2+ into the βTCP was shown to induce excellent bioactivities that were absent in the pristine βTCP. Enhancement, coupled with good antimicrobial properties against Escherichia coli (E. coli), suggests that Mg2+/Zn2+ co-doping TCP can be developed further into antibacterial bone cement. As synthesized, it would be considered a potential biomaterial for orthopedic applications.

We have devised a highly efficient methodology for the synthesis of high-purity Mn 4 C, involving arc-melting, subsequent homogenization, and water-quenching steps. This approach overcomes previous constraints associated with limited batch sizes and low purity, enabling the fabrication of substantially larger quantities. In pursuit of achieving the high-purity Mn 4 C phase, we conducted optimization studies on the stoichiometry of Mn/C in the raw materials, as well as on the homogenization temperature and time. Through this optimization process, we successfully produced highly pure Mn 4 C ingots by subjecting Mn 4.7 C alloys to homogenization at temperatures ranging from 1050 to 1200 ℃ for 5 hours, followed by rapid water quenching. The utilization of water quenching served to stabilize the Mn 4 C phase formed at high temperatures during the homogenization process, thus preventing its transformation into undesired low-temperature phases. The magnetic and physical properties of the samples with highly pure Mn 4 C phase, quenched from various temperatures, were investigated, revealing subtly distinct characteristics. The pure Mn 4 C sample obtained by quenching from 1100 °C exhibited a Néel temperature of approximately 950 K, a saturation magnetization of 8.4 Am2/kg, and a positive temperature coefficient (α) of magnetization of 0.0113 Am2/kg·K, respectively. Notably, the abnormal augmentation of thermomagnetic properties over a wide temperature range, from 5 to approximately 650 K, underscores the potential of high-purity Mn 4 C as a promising candidate for devices where the thermal stability of magnetic properties is of paramount importance. • A methodology for pure Mn 4 C addressing previous complexities and inefficiencies. • Enabled exploration of potentially functional properties for pure Mn 4 C bulk. • Smaller cell (3.862 Å) compared to (3.8682 Å) [13] suggests more stable structure. • Lager α (0.0113 Am2/kg·K) indicates pure phase compared to 0.0072 Am2/kg·K [13]. • Findings offer potential for controlling the thermomagnetic properties of magnets. [ABSTRACT FROM AUTHOR]

The design and development of efficient electrocatalysts for water splitting, particularly for thermodynamically unfavorable oxygen evolution reaction (OER), is one of the foremost requirements to develop sustainable hydrogen production technologies. This requires a thorough understanding of various characteristics of an electrocatalyst that can influence its performance. Layered hydroxides, such as β-Co-(OH)2, are promising OER electrocatalysts; however, they tend to transform to the CoOOH phase during synthesis. In this work, we have evaluated the influence of the oxyhydroxide impurity phase on the OER activity of two-dimensional β-Co-(OH)2. Our study reveals that the CoOOH impurity in β-Co-(OH)2 nanosheets improves the thermodynamics of OER (overpotentials of 322 and 369 mV at a 10 mA·cm–2 current density in the presence and absence of impurity), while adversely impacting the reaction kinetics (Tafel slopes of 142.3 and 96.5 mV·dec–1, respectively). These concurrent synergistic and antagonistic behaviors of the CoOOH phase are interesting and emphasize the importance of well-controlled synthesis conditions and thorough catalyst characterization to develop sustainable catalytic technologies. [ABSTRACT FROM AUTHOR]

Various concentration of manganese metal ions (x = 0.01, 0.02, 0.03, 0.04, 0.05 mol%) doped Sodium Magnesium Phosphate (SMP) NaMg4(PO4)3 compounds were made through combustion-reaction method. The powder X-ray diffraction (XRD) pattern confirms that Mn2+ ions were incorporated into the NaMg4(PO4)3 host lattice forming a complete solid solution. Elemental analysis and surface morphology were examined from the EDX spectrum and corresponding element mapping by scanning electron microscopy. The Photoluminescence spectra of Mn-doped SMP samples exhibited a strong visible emission peak at the wavelength of 617 nm, which indicated that spinforbidden transition takes place from 4T1g (G) to 6A1g (S) with inversion symmetry. The photoluminescence profiles exhibited the quenching in emission intensity above 0.03 mol% of Mn(NO3)2 due to the availability of more octahedral Mn2+ ions. These outputs show that Mn2+ activated NaMg4(PO4)3 material can fulfill application in redemitting phosphor-based LEDs devices. [ABSTRACT FROM AUTHOR]

Embedding all-inorganic cesium lead halide CsPbX 3 (X=Cl, Br, I) perovskite quantum dots (PQDs) PQDs into glass is one of the most effective strategies to improve their optical, thermal and chemical stabilities. Herein, by using PbO instead of PbBr 2 as the lead source, it is effective to lower the melting temperature and reduce the volatilization pollution from lead halide raw materials. Thus, a high-purity CsPbBr 3 PQDs embedded glass with 71.5 % PLQY was successfully prepared. The thermal stability, and photo-aging properties were also improved. By simply changing the halogen element, the red and blue CsPbX 3 PQDs embedded glasses were successfully prepared. The white LED fabricated by coating obtained green/red CsPbX 3 PQDs embedded glass on a blue chip displays high color gamut of 121.9 % NTSC standard and >91.1 % Rec. 2020 standard, which embodies the great potential of PQDs embedded glass in lighting and display fields. [ABSTRACT FROM AUTHOR]

Inorganic perovskites with cesium (Cs+) as the cation have great potential as photovoltaic materials if their phase purity and stability can be addressed. Herein, a series of inorganic perovskites is studied, and it is found that the power conversion efficiency of solar cells with compositions CsPbI1.8Br1.2, CsPbI2.0Br1.0, and CsPbI2.2Br0.8 exhibits a high dependence on the initial annealing step that is found to significantly affect the crystallization and texture behavior of the final perovskite film. At its optimized annealing temperature, CsPbI1.8Br1.2 exhibits a pure orthorhombic phase and only one crystal orientation of the (110) plane. Consequently, this allows for the best efficiency of up to 14.6% and the longest operational lifetime, TS80, of ≈300 h, averaged of over six solar cells, during the maximum power point tracking measurement under continuous light illumination and nitrogen atmosphere. This work provides essential progress on the enhancement of photovoltaic performance and stability of CsPbI3 − xBrx perovskite solar cells. [ABSTRACT FROM AUTHOR]

The rational creation of two-component conjugated polymer systems with high levels of phase purity in each component is challenging but crucial for realizing printed soft-matter electronics. Here, we report a mixed-flow microfluidic printing (MFMP) approach for two-component π-polymer systems that significantly elevates phase purity in bulk-heterojunction solar cells and thinfilm transistors. MFMP integrates laminar and extensional flows using a specially microstructured shear blade, designed with fluid flow simulation tools to tune the flow patterns and induce shear, stretch, and pushout effects. This optimizes polymer conformation and semiconducting blend order as assessed by atomic force microscopy (AFM), transmission electron microscopy (TEM), grazing incidence wide-angle X-ray scattering (GIWAXS), resonant soft X-ray scattering (R-SoXS), photovoltaic response, and field effect mobility. For printed all-polymer (poly[(5,6-difluoro-2-octyl-2H-benzotriazole-4,7-diyl)-2,5-thiophenediyl[ 4,8-bis[5-(2-hexyldecyl)-2-thienyl]benzo[1,2-b:4,5-b']dithiophene- 2,6-diyl]-2,5-thiophenediyl]) [J51]:(poly{[N,N'-bis(2-octyldodecyl) naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5'-(2,2'-bithiophene)}) [N2200]) solar cells, this approach enhances short-circuit currents and fill factors,with power conversion efficiency increasing from 5.20% for conventional blade coating to 7.80% for MFMP. Moreover, the performance of mixed polymer ambipolar [poly(3- hexylthiophene-2,5-diyl) (P3HT):N2200] and semiconducting:insulating polymer unipolar (N2200:polystyrene) transistors is similarly enhanced, underscoring versatility for two-component π-polymer systems. Mixedflow designs offer modalities for achieving high-performance organic optoelectronics via innovative printing methodologies. [ABSTRACT FROM AUTHOR]

Inorganic lead halide perovskite CsPbBr 3 offers attractive photophysical properties and phase stability for high-performance optoelectronic devices. However, CsPbBr 3 films produced by the classic solution-based two-step method are always accompanied with impurity phases of CsPb 2 Br 5 and Cs 4 PbBr 6 , which represents a major efficiency-limiting factor for future advances of CsPbBr 3 -based devices. The challenge lies in the complexity of the Cs-Pb-Br phase system, requiring both spatially and temporally precise control of the precursor stoichiometry during solution-phase growth of CsPbBr 3 films. By adopting 2-methoxyethanol as the solution conversion medium instead of commonly applied methanol, the reaction between CsBr and PbBr 2 can be finely controlled to yield single phase CsPbBr 3 films within a few minutes; extending the solution-conversion step to 24 h does not alter the phase purity of resulting CsPbBr 3 films. The present work paves the way to regulate the crystal growth behaviors of two-step solution-processed CsPbBr 3 films by simple solvent engineering. [ABSTRACT FROM AUTHOR]

This work demonstrates for the first time that switching from sol-electrospinning to sol-electrospraying using PVP as a carrier polymer leads to enhanced purity of rhombohedral zinc titanate (Rh-ZTO) after calcination. Unlike in sol-electrospinning, the purity systematically increases and crystallite size decreases as PVP concentration is increased in sol-electrospraying. 100% pure Rh-ZTO powders were prepared with PVP fraction of 31.25 wt%. After careful characterization by XRD, rheology, zeta potential measurements, and SEM, we conclude that the interaction of multipole moments of the incipient sol-clusters with the electrostatic field influences the purity. We propose that in electrospinning the sol clusters spatially separate to yield multiple crystalline phases whereas in electrospraying they intermix due to polymeric cages in droplets and yield a single crystalline phase. The highest purity samples were found to enhance photo-reduction of 4-nitrophenol in presence of visible light, with rate constant increasing from 0.000415 to 0.00104 min−1. This could result from complex formed between oxygen vacancy and the shallow donor states of Ti3+ as confirmed by DRS, XPS, and PL. [Display omitted] • Rhombohedral ZTO fraction goes up with PVP in electrospraying but not in spinning. • Increasing PVP in the sol gives smaller crystallites and higher bandgap. • Polymer chains prevent cluster separation and promote homogenization in spraying. • Electrospraying with polymers can be a good way to achieve phase purity in oxides. • Pure Rh-ZTO prepared this way reduces 4-nitrophenol in presence of visible light. [ABSTRACT FROM AUTHOR]

In a systematic investigation, the synthesis of metal–organic frameworks (MOFs) with MIL‐140 structure was studied. The precursors of this family of MOFs are the same as for the formation of the well‐known UiO‐type MOFs although the synthesis temperature for MIL‐140 is significantly higher. This study is focused on the formation of Zr‐based MIL‐140 MOFs with terephthalic acid (H2bdc), biphenyl‐4,4′‐dicarboxylic acid (H2bpdc), and 4,4′‐stilbenedicarboxylic acid (H2sdc) and the introduction of synthesis field diagrams to discover parameters for phase‐pure products. In this context, a MIL‐140 network with H2sdc as linker molecule is first reported. Additionally, an important aspect is the reduction of the synthesis temperature to make MIL‐140 MOFs more accessible even though linkers with a more delicate nature are used. The solvothermal syntheses were conducted in highly concentrated reaction mixtures whereby a targeted synthesis to yield the MIL‐140 phase is possible. Furthermore, the effect of the often‐used modulator approach is examined for these systems. Finally, the characteristics of the synthesized MOFs are compared with physisorption measurements, thermogravimetric analyses, and scanning electron microscopy. [ABSTRACT FROM AUTHOR]

In this study, for the synthesis of calcium hydroxyapatite (Ca10(PO4)6(OH)2; CHAp), an environmentally-friendly water-based sol–gel chemistry approach using food products as calcium and phosphorus precursors has been developed. In the sol–gel processing, the food products having the greatest calcium and phosphorus concentrations and the calculated calcium and phosphorus molar ratio closest to Ca/P = 1.67 were selected as starting materials (hard cheese "Dziugas", preserved Atlantic sardines in oil, low-fat yogurt "Dobilas", and pumpkin seeds). The synthesis products were investigated by thermal analysis (TG/DTG-DSC), infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD) analysis, and scanning electron microscopy (SEM). The content of Ca and P in the food products was determined by means of ICP-OES. Highlights: An environment-friendly sol-gel chemistry approach for calcium hydroxyapatite was developed. Sol-gel processing using food products as calcium and phosphorus precursors was performed. Ca10(PO4)6(OH)2 as the main crystalline phase was formed when pumpkin seeds were used. The chemical composition of the end products depended on when the egg shells were used. Attempts to fabricate monophasic CHAp using the solid-state reaction approach were not successful. [ABSTRACT FROM AUTHOR]

With a stacking-layered architecture, the bilayer two-dimensional-three-dimensional (2D-3D) perovskite heterostructure (PHS) not only eliminates surface defects but also protects the 3D perovskite matrix from external stimuli. However, these bilayer 2D-3D PHSs suffer from impaired interfacial charge carrier transport due to the relatively insulating 2D perovskite fragments with a random phase distribution. Over the past decade, substantial efforts have been devoted to pioneering molecular and structural designs of the 2D perovskite interlayers for improving their charge carrier mobility, which enables state-of-the-art perovskite solar cells with high power conversion efficiency and exceptional operational stability. Herein, this review offers a comprehensive and up-to-date overview on the recent progress of bilayer 2D-3D PHSs, encompassing advancements on spacer cation engineering, interfacial charge carrier modification, advanced deposition protocols, and characterization techniques. Then, the evolutionary trajectory of bilayer 2D-3D PHSs is outlined by summarizing its mainstream development trends, followed by a perspective discussion about its future research opportunities toward efficient and durable perovskite solar cells.

Abstract The synthesis of ZIF-11 in N , N -Diethylformamide (DEF) at varying reaction temperatures, times and different molar compositions of the reaction mixture was investigated in detail in order to identify ranges of the formation of phase-pure ZIF-11. Since it is known that water in the solvent DEF leads to the formation of the phase impurity ZIF-7-III during the ZIF-11 synthesis, all reactions were carried out in DEF exhibiting water contents below 0.1 wt%. The variations of the molar ratio of substrates Zn:bIm:DEF = 1:x:y as well as the synthesis temperature and time revealed a number of phase transitions within the ZIF-11 synthesis. Highly crystalline ZIF-11 was obtained for a molar ratio Zn:bIm:DEF of 1:15:1400 already after 3 h of reaction at 60 °C and 100 °C. Depending on the reaction vessel, the water content of the solvent as well as the temperature, ZIF-11 transformed to the dense phase ZIF-7-III within different reaction times. It was concluded that ZIF-11 represents a metastable reaction product. SEM images of the samples obtained after different synthesis times showed that ZIF-11 undergoes successive dissolution-recrystallization cycles in combination with heterogeneous nucleation. For a reduced amount of solvent, the formation of ZIF-11 proceeded faster, but ZIF-11 with lower maximum relative crystallinity was formed. For lower ratios of solvent to zinc, the time range of stable ZIF-11 formation was smaller as compared to higher solvent amounts. The variations of the ratio of zinc to the linker benzimidazole showed that ZIF-11 formation was slower for lower molar ratios, e.g. 1:2:1400 and 1:4:1400. ZIF-11 with the highest relative crystallinity and a pore volume of 0.43 cm3 g−1 was formed after 3–12 h of reaction at molar ratios Zn:bIm:DEF of 1:8:1400 and 1:12:1400. Another phase transition was observed for synthesis times of 6–96 h for a molar ratio of 1:2:1400. Under those conditions, an unidentified layered crystalline product was found and similarities to the layered ZIF-L were identified. Graphical abstract Image 1 Highlights • A systematic study on ZIF-11 formation at different synthesis conditions in N , N -Diethylformamide is provided. • Phase-transition products occuring during the ZIF-11 synthesis are characterized in detail. • Optimum parameters for obtaining highly crystalline, pure-phase ZIF-11 are given. [ABSTRACT FROM AUTHOR]

Highlights • Sn loss was suppresed using stack Cu/Sn/Cu at 500 °C. • The formation of single phase CTS was obtianed at 500 °C and 1 Pa. • The Cu-poor composition is preferable for deposition of single phase M-CTS. Abstract In this study, the deposition of Cu 2 SnS 3 (CTS) thin films was carried out at different sulfurization temperatures in the range of 350–550°C under high vacuum of 1 Pa using the sputtered Cu/Sn/Cu metal precursor layers in the sulfur vapor atmosphere. In order to reduce the Sn loss, a particular metal stack of Cu/Sn/Cu was used. Single phase monoclinic (M)-CTS thin film was obtained at 500 °C. The high intensity Raman modes at 292 cm−1 and 350 cm−1 further confirmed the formation of M-CTS. The M-CTS thin film sulfurized at 500 °C showed a composition of Cu/Sn = 1.89 and an optical band gap energy of 0.94 eV. Hall effect measurement of the film sulfurized at 500 °C with Cu/Sn ratio of 1.82 showed an electrical resistivity of 7.30 Ω-cm, carrier concentration of 6.29 × 1017 cm−3, and mobility of 1.36 cm2/Vs. Our results indicate that the copper-poor composition with a stacking order of Cu/Sn/Cu is favored in order to attain the single phase M-CTS. [ABSTRACT FROM AUTHOR]

Abstract Characterization of U 3 Si 2 fresh fuel pellets is important for quality assurance and validation of the finished product. Grain size measurement methods; phase identification methods, using scanning electron microscopes equipped with energy dispersive spectroscopy, and x-ray diffraction; and phase quantification methods, via image analysis, have been developed and implemented on U 3 Si 2 pellet samples. A wide variety of samples were characterized that fall into 3 fabrication periods: 1. Representative pellets from an initial irradiation experiment, 2. Small scale batches that improved upon experience from the first period, and 3. Pellets fabricated at a slightly larger scale using optimized methods to enhance phase purity. The average grain size for pellets from the first period of fabrication was between 16 and 18 μm. The typical average grain size for pellets from the second period of fabrication was between 20 and 30 μm. In the third period of fabrication samples exhibited irregular grain growth with a bimodal grain size distribution consisting of coarsened grains (>80 μm in most samples) surrounded by the typical (20–30 μm) grain structure around the surface. Phases identified in the first period uranium silicide pellets included: U 3 Si 2 as the main phase composing about 80 vol %, Si rich phases (USi and U 5 Si 4) composing about 13 vol %, and UO 2 composing about 5 vol %. U 3 Si 2 pellet samples from the second period of fabrication had similar phases and phase quantities. Pellet batches from the third period of fabrication did not contain Si rich phases, and had between 1 and 5% UO 2 : achieving U 3 Si 2 phase purity between 95 vol % and 98 vol % U 3 Si 2. The amount of UO 2 in sintered U 3 Si 2 pellets is correlated to the length of time between U 3 Si 2 powder fabrication and pellet formation. These measurements provide information necessary to optimize fabrication efforts and a baseline for future work on this fuel compound. [ABSTRACT FROM AUTHOR]

Smectite is widely used in many industrial fields and material applications. Although the high phase purity and yield of synthetic smectite are paramount for advanced applications, few studies have investigated these aspects. In this work, the phase purity and yield of synthetic smectite were estimated for the first time using a quantitative phase analysis through X-ray diffraction and Rietveld method software. The Taguchi method was used to optimize the phase purity and yield of synthetic smectite, and the effects of synthesis factors are discussed. Based on the trioctahedral smectite formula Na 2x (Al 2(1-x) Mg 2x □)Si 4 O 10 (OH) 2 , an Na 2 O-MgO-Al 2 O 3 -SiO 2 -H 2 O system was used for smectite synthesis at temperatures of 200 °C and 220 °C, for durations of 48–96 h and pH values of 7, 9, and 11. The results indicate that the duration, starting material, and type of mineralizer are the three most important factors affecting the phase purity and yield of synthetic smectite. For the synthesis conditions optimized by the Taguchi method in this study, the phase purity and yield of the synthetic smectite can reach up to 92.5% and 88.3%, respectively. These results can contribute to an improved understanding of the factors that control the phase purity and yield of synthetic smectite and provide an efficient method for the synthesis of high-quality smectite for advanced applications. [ABSTRACT FROM AUTHOR]

This study is the first application of Bayesian optimization to the synthesis process of superconducting materials. As a model case, the phase purity of BaFe 2 (As,P) 2 polycrystalline bulks, which affects their superconducting properties, was improved by optimizing only the heat-treatment temperature using Bayesian optimization. We determined the optimal temperature among 800 candidates in 13 experiments, and a phase purity of 91.3 % was achieved. Moreover, the phosphorus doping level of the best sample approached the optimal doping level owing to a reduction in the impurity phase. Visualization of the Bayesian optimization process showed that a well-balanced global search and local optimization allowed us to obtain a rough correlation between the superconducting properties and experimental conditions and finely optimal experimental conditions over a wide range. These results demonstrate that Bayesian optimization is promising for optimizing the synthesis process of superconducting materials. • Bayesian optimization was applied to the synthesis process of P-doped Ba122. • The phase purity of P-doped Ba122 polycrystalline bulk was achieved at 91.3 %. • The heat treatment temperature was optimized to 863 °C from a range of 200–1000 °C. • Synthesis of superconducting materials was accelerated by Bayesian optimization. [ABSTRACT FROM AUTHOR]

In this study, the authors synthesised gold nanoparticles (Au NPs) by a green approach using an aqueous extract of empty cotton boll peels (ECBPs) which was rapid, simple and inexpensive eco‐friendly method compared to chemical and physical methods. The ECBP aqueous extract played a vital role in the reduction of Au+3 ions into Au NPs which was further confirmed by analytical characterisation. The phase purity and crystallinity of Au NPs were confirmed by X‐ray diffraction analysis. The characteristic functional groups of synthesised Au NPs were identified by Fourier transform infrared analysis. The surface morphology and topography of Au NPs were studied by scanning electron microscopy and transmission electron microscopy analysis. Size with dispersion stability of Au NPs was determined by dynamic light scattering and zeta potential studies. In this study, the authors performed a catalytic activity of Au NPs using different pollutant organic dyes such as methylene blue and methyl orange. It also showed good antioxidant activity compared to standard ascorbic acid by using the standard 1,1‐diphenyl‐2‐picryl‐hydrazil method. Hence, this study concluded that ECBP mediated Au NPs could act as a promising material for degradation of dyes and antioxidant activity. [ABSTRACT FROM AUTHOR]

Phase-pure MnCrFeO4 particles were synthesized by the controlled precipitation and the effect of calcination on different properties were investigated. XRD results showed intermediate phases in the particles calcined at 800 °C, while complete transformation into spinel phase at 1000 °C. The particle size increased linearly with calcination temperature. The increase in AC conductance with frequency showed the involvement of small polarons in the conduction mechanism. The dielectric constant and loss tangent steeply decreased while remained constant over the high frequency range. The phase-pure MnCrFeO4 particles showed lowest dielectric losses that make them a promising candidate for application in highfrequency devices. [ABSTRACT FROM AUTHOR]

Cu 2 ZnSnS 4 (CZTS) absorber layers were synthesized by electrodeposition of Cu-Zn-Sn (CZT) alloys using horizontally or vertically oriented electrodes, followed by sulfurization. A significant improvement in compositional homogeneity was observed for the horizontal vs. vertical deposition configuration, most probably due to the absence of buoyancy-induced convection and the improved uniformity of the current distribution in the former. The morphology of the two CZT films is similar, but the films grown from the horizontal, facing down electrode, show some pinholes related to the adhesion of hydrogen bubbles. The horizontally grown and sulfurized CZTS films show also a better homogeneity and improved phase purity, as demonstrated by EDS mapping and imaging. The disorder due to anti-site defects in as-sulfurized CZTS films is decreased by gentle annealing, which also results in improved crystallinity. Liquid junctions were utilized to measure film photoactivity, showing that the horizontally grown films exhibit twice as much the photocurrent from the vertically grown ones; the dark current however was higher in the former, probably owed to the presence of pinholes that provide a short circuit between the electrolyte and substrate. [ABSTRACT FROM AUTHOR]

The LSGM powders by doping 0–2.5 at.% of MoO 3 were synthesized and investigated. The microstructure and electrical properties of the samples were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) and electrochemical impedance spectroscopy (EIS) respectively. The results showed that the phase purity, densification and conductivity of the LSGM samples could be improved by a proper addition of MoO 3 . The LSGM specimen by doping 2 at.% MoO 3 exhibited the best phase purity, the best density, the largest grain size and the lowest activation energy. Moreover, it was found that the conductivity of the LSGM by doping 2 at.% MoO 3 was 3.91 × 10 −4 S cm −1 at 450 °C, which was 2.82 times as high as LSGM without MoO 3 doping. Moreover, the thermal expansion coefficient of the LSGM-2Mo sample changed little by MoO 3 doping. Therefore, the MoO 3 doped LSGM may be a potential electrolyte material for anode-supported solid oxide fuel cells (SOFCs) without requiring buffer layer between anode and electrolyte. [ABSTRACT FROM AUTHOR]

The phase pure hollow Zn 2 SnO 4 and green emitting ZnO-SnO 2 -Zn 2 SnO 4 composite fiber have been prepared by post calcining the as formed fiber by electrospin technique. Depending upon the calcination temperature, the as prepared fiber exhibited a striking variation in composition, microstructure, optical and photo-electrochemical properties. The composition dependent dissimilarity in photovoltaic performance and photocatalytic activity has been established in this work. A relatively enhanced open circuit voltage (Voc) of 0.76 V, fill factor (FF) of 59.78%, short circuit current (Jsc) of 4.2 mA/cm 2 and an overall conversion efficiency (ɳ) of 1.93% have been achieved for the phase pure Zn 2 SnO 4 porous fiber obtained at the elevated calcination temperature of 1000 °C. On the contrary, a relatively reduced Voc, FF, J SC and ɳ of 0.70 V, 42.54%, 3.8 mA/cm 2 and 1.17%, respectively, have been achieved for the 800 °C calcined dense fiber consisting of a mixture of three distinct phases ZnO, SnO 2 and Zn 2 SnO 4 . Unlike photovoltaic behaviour the trend in photocatalytic performance interestingly got reversed for the ZnO-SnO 2 -Zn 2 SnO 4 composite fiber owing to its superior photo-induced charge separation ability followed by generation of larger amount of active hydroxyl radicals (OH . ). Our results establish the composite fiber as a preferred photocatalyst in comparison to phase pure Zn 2 SnO 4 towards the textile dyes Methylene blue and Congo red and non absorbing organic pollutants such as Phenol and Bisphenol A under UV illumination. [ABSTRACT FROM AUTHOR]