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The study investigates the two different underlying ablation mechanisms of WS2 processed by femtosecond (fs) laser with different fluences. With increasing fluence, the saturable expansion of craters and the transformation of three distinct crater morphologies are found. The material response and the transfer and deposition of laser energy are tracked by using a plasma model based on the classical single rate equation model and the Drude model. The results of the numerical simulation and time-resolved transient reflectivity reveal the two different ablation mechanisms, which are coulomb explosion and phase explosion. The mechanism of material removal is distinguished by the critical threshold of 0.85 J/cm2. In addition, the internal ablation region exhibits a high concentration of defects and WO3 according to the results of Raman spectra, X-ray photoelectron spectra, and morphology-dependent photoluminescence mapping. Due to the high concentration with high fluence, the device of WS2/Si p-n junction exhibits a 2.6 times enhancement on the current under forward bias. The findings would be of value to engineer structures to tailor the optoelectronic response of WS2 and to develop potential future optoelectronic devices. [ABSTRACT FROM AUTHOR]

The wetting and sticking phenomena are the principal factors that lead to dislocation, parasitic grain nucleation, cracking, and other issues during crucible-based crystal growth of Cd-based crystals (CdTe/Cd1−xZnxTe). The trace amount of moisture in raw materials is an important factor influencing the sticking process, but this has not been sufficiently studied. Here, we investigate the chemical reactions between trace moisture and raw Cd materials by introducing H2O intentionally. The X-ray photoelectron spectra of the sticky surface indicate that residual moisture can react with raw Cd and generate more CdO compared with the untreated Cd. The reactive gas atmosphere process (RAP) method with a self-designed crucible was modified for the removal of moisture and reaction products. The waste products of the RAP method were successfully separated and determined to be CdCl2, CdCO3, CdO, and SiO2. The whole chemical process of oxidation and the RAP method was proposed accordingly. The purified Cd showed a spherical shape derived from the surface tension and de-wetting with the bare quartz crucible. These studies provide a comprehensive description of the moisture-driven oxidation behavior of Cd responsible for the sticking problem of the Cd/SiO2 system, which may guide high-quality Cd-based crystal growth techniques. [ABSTRACT FROM AUTHOR]

The present study discusses the synthesis and characterization of Co-doped CeO2 quantum dots obtained via the chemical precipitation technique. The crystalline nature, optical properties, nanostructure, and magnetic behavior of the prepared samples have been investigated using various experimental techniques. The face-centered cubic structure of the Co-doped CeO2 quantum dots was demonstrated by the structural confirmation. The crystallite size was observed to decrease from 10.11 to 5.84 nm when the cobalt dopant concentration increased from 0 to 6%. Optical analysis revealed a significant blue shift in the UV absorption spectrum from 246 to 220 nm, resulting in a bandgap increase from 5.04 to 5.64 eV. The photoluminescence analysis indicates that the added Co dopant decreased the emission intensity. The peak shift from 512 to 532 cm−1 in Fourier transform infrared spectra confirmed the cobalt ion doping. The displacement of the Raman peak from 462 to 441 cm−1 further confirmed the space group Fm 3 ¯ m of CeO2. TEM images revealed that the CeO2 samples without Co were spherical, but those with Co were nanorods. Energy-dispersive x-ray spectrum and x-ray photoelectron spectra confirmed the Co dopant. The vibrating sample magnetometer study confirmed the magnetic transition from weak to strong ferromagnetic transition due to Co dopant. Electron spin resonance spectra established the ferromagnetic character of undoped and Co-doped cerium oxide quantum dots. [ABSTRACT FROM AUTHOR]

This work presents pulsed UV laser treatment (355 nm, 2 Hz) of TiO2 nanotubes decorated with chromium oxides. The modification was performed in a system equipped with a beam homogenizer, and during the irradiation, the samples were mounted onto the moving motorized table. In such a system, both precisely selected areas and any large area of the sample can be modified. Photoelectrochemical tests revealed photoresponse of laser-treated samples up to 1.37- and 18-fold under the illumination with ultraviolet-visible and visible light, respectively, in comparison to bare titania. Optimal beam energy fluence regarding sample photoresponse has been established. Scanning electron microscopy images, X-ray diffraction patterns, along with Raman and X-ray photoelectron spectra, suggest that the enhanced photoresponse results from changes solely induced in the layer of chromium oxides. It is believed that the results of the present work will contribute to a wider interest in laser modification of semiconductors exhibiting improved photoelectrochemical activity. [ABSTRACT FROM AUTHOR]

Hydrogen sulfide (H2S) detection is extremely necessary due to its hazardous nature. Thus, the design of novel sensors to detect H2S gas at low temperatures is highly desirable. In this study, a series of nanocomposites based on MoS2 octahedrons and ZnO-Zn2SnO4 nanoparticles were synthesized through the hydrothermal method. Various characterizations such as X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectrum (XPS) have been used to verify the crystal phase, morphology and composition of synthesized nanocomposites. Three gas sensors based on the nanocomposites of pure ZnO-Zn2SnO4 (MS-ZNO-0), 5 wt% MoS2-ZnO-Zn2SnO4 (MS-ZNO-5) and 10 wt% MoS2-ZnO-Zn2SnO4 (MS-ZNO-10) were fabricated to check the gas sensing properties of various volatile organic compounds (VOCs). It showed that the gas sensor of (MS-ZNO-5) displayed the highest response of 4 to 2 ppm H2S and fewer responses to all other tested gases at 30 °C. The sensor of MS-ZNO-5 also displayed humble selectivity (1.6), good stability (35 days), promising reproducibility (5 cycles), rapid response/recovery times (10 s/6 s), a limit of detection (LOD) of 0.05 ppm H2S (Ra/Rg = 1.8) and an almost linear relationship between H2S concentration and response. Several elements such as the structure of MoS2, higher BET-specific surface area, n-n junction and improvement in oxygen species corresponded to improving response. [ABSTRACT FROM AUTHOR]

• Cu ions were implanted in TiO 2 NPNF matrix at fluence of 5 × 1012, 5 × 1013, 5 × 1014 and 5 × 1015 ions.cm−2. • Formation of substitutional Cu+ and Cu2+ was detected at lower and higher fluence respectively. • Photoanode with Cu2+ ion suffered from poor dye loading and higher recombinations. • Photoanode with Cu+ ion exhibits enhanced light harvesting and minimal charge recombinations. • DSSCs with maximum Cu+ content (5 × 1014 ions.cm−2) exhibited 7.35% PCE as compared to 6.22% of pristine DSSCs. Among noble metals, doping of copper (Cu) in TiO 2 for dye sensitized solar cells (DSSCs) has always been controversial exhibiting both positive and negative results throughout the literature due to its relatively lesser known doping mechanism. We, hereby, have tried to resolve the controversy and provide detailed information on conditions under which Cu can increase performance of DSSCs. Firstly, for Cu doping, a very controlled and precise doping technique of ion implantation was employed in TiO 2 photoanodes at variable fluence. From the X-ray diffraction spectra, Cu ions were found to be present at substitutional sites in TiO 2 matrix. Interestingly X-ray photoelectron spectra reveal that lower Cu fluences result in production of Cu+ ion whereas at higher fluence Cu2+ ion starts dominating. Further, optical studies reveal that introduction of Cu2+ at higher fluence suffer from poor dye loading and higher recombinations due to distorted morphology and improper band alignment. Hence, DSSC prepared with maximum Cu+ content (fluence of 5 × 1014 ions.cm−2) exhibits efficiency of 7.35 % as compared to 6.22 % of pristine unimplanted DSSC, due to higher light harvesting, upward fermi level and lower recombinations. Further, DSSC with Cu2+ ion show poor performance (5.61 %) due to lower electron injection efficiency, despite of superior open circuit voltage values. [ABSTRACT FROM AUTHOR]

Core–shell structure Cu@Pd/C catalysts were prepared in two steps combining microwave-assisted glycol reduction and chemical impregnation method for the first time. Compared with the traditional one-step synthesis of PdCu/C alloy catalysts by microwave (marked as M-PdCu/C) and impregnation (denoted by I-PdCu/C) method, respectively. The Cu@Pd/C catalysts were prepared in two-step show better catalytic performance toward formic acid oxidation, due to its special core–shell structure and better dispersion. On this basis, different proportions of Cux@Pdy/C (x:y = 1:1, 1:2, 1:3, 1:4 and 1:5) catalysts were synthesized by the two-step strategy. The relationship between lattice strain, electron distribution and catalytic performance were explored by physical and chemical characterization. X-ray diffraction and X-ray photoelectron spectra analyses showed that the introduction of Cu lead to the lattice contraction and modified electronic structure of Pd. The electrochemical test showed that Cu@Pd3/C sample has the highest activity toward formic acid electro-oxidation. Its mass activity is about 3.3 times that of Pd/C catalyst that was synthesized by impregnation method (labelled as I-Pd/C). At the same time, the Cu@Pd3/C catalyst also demonstrated improved stability. The low-palladium catalyst with a Pd–Cu shell–core structure was synthesized by two-step method and has excellent catalytic activity and stability for formic acid electro-oxidation. [ABSTRACT FROM AUTHOR]

The structure of carbon materials can be controlled using a magnetic field, enhancing their functional properties. Most of the magnetic-field effects on carbon material growth were found to originate from the magnetic-field orientation. However, we observed that the magnetic-field orientation did not affect the growth of single-walled carbon nanotubes (SWCNTs); instead, under a magnetic field of 10 T, the preferential growth of metallic SWCNTs (1-nm diameter) was observed using chemical vapor deposition and liquid decomposition, suggesting chirality selectivity. Raman and X-ray photoelectron spectra showed that the defect structure and oxygen content of SWCNTs increased with increasing magnetic-field intensity. Therefore, thin metallic nanotubes can be selectively grown by applying a high magnetic field in environments where nanotubes are relatively difficult to form. [ABSTRACT FROM AUTHOR]

A famous winged sandstone sculpture named Bixie of the Wei and Jin Dynasties (220 ~ 420 AD) is placed on the right side of the Chongqing Three Gorges Museum, accompanied by serious weathering on its surface. To explore the structural and compositional properties of the weathered, exfoliated, repaired cement, and yellow crust samples, scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray fluorescence spectrometer (XRF), Fourier transform infrared spectroscopy (FTIR), thermal analysis (TGA/DTG), and X-ray photoelectron spectrum (XPS) were applied to determine the efflorescence that occurred on the surface of sandstone sculpture and repair cement. The results show that a high concentration of gypsum was detected in the weathering sample, which indicated that the deterioration of the stone body of Bixie was caused by the combined action of internal salt crystallisation and external air pollution. Both SO2 in the atmosphere and SO2-4 in acid rain react with substances containing calcium in sandstone to form anhydrite that causes expansion in volume, resulting in loosening and crisp powder on the surface of sandstone. The formation of the Fe-rich concretions and stagnant Fe2+-rich water on the surface, reacting with sulphur oxides in the atmosphere, will cause the stone carving surface to turn yellow. Cement is prone to corrosion due to carbonization and corrosion of gypsum, so it is necessary to replace the cement in the subsequent repair. This study reveals the properties of the surficial stain above the sandstone sculpture in the Chongqing China Three Gorges Museum, providing important information for their protection and restoration. [ABSTRACT FROM AUTHOR]

We present machine learning models based on kernel-ridge regression for predicting x-ray photoelectron spectra of organic molecules originating from the K -shell ionization energies of carbon (C), nitrogen (N), oxygen (O), and fluorine (F) atoms. We constructed the training dataset through high-throughput calculations of K -shell core-electron binding energies (CEBEs) for 12 880 small organic molecules in the bigQM7 ω dataset, employing the Δ-SCF formalism coupled with meta-GGA-DFT and a variationally converged basis set. The models are cost-effective, as they require the atomic coordinates of a molecule generated using universal force fields while estimating the target-level CEBEs corresponding to DFT-level equilibrium geometry. We explore transfer learning by utilizing the atomic environment feature vectors learned using a graph neural network framework in kernel-ridge regression. Additionally, we enhance accuracy within the Δ-machine learning framework by leveraging inexpensive baseline spectra derived from Kohn–Sham eigenvalues. When applied to 208 combinatorially substituted uracil molecules larger than those in the training set, our analyses suggest that the models may not provide quantitatively accurate predictions of CEBEs but offer a strong linear correlation relevant for virtual high-throughput screening. We present the dataset and models as the Python module, cebeconf , to facilitate further explorations.

High resolution X-ray photoelectron spectra of a series of substituted pyridines (pyridine, 2-fluoropyridine, and 2,6-difluoropyridine) have been recorded and rationalized by means of a quantum mechanical approach based on the density functional theory including vibronic effects at the Franck-Condon level. The significant chemical shifts of the C1s binding energies induced by fluorine atoms are reproduced quantitatively by our computational model, as well as the vibrational fine structure and the band shapes. Nonsymmetric normal modes play an important role due to the core-hole localization in the presence of equivalent carbon atoms in pyridine and 2,6-difluoropyridine. [ABSTRACT FROM AUTHOR]

Sn-doped In 2 O 3 (ITO) nanoparticles with various Sn doping concentrations were successfully fabricated using a liquid phase coprecipitation method. Similar to sputtered ITO thin films, Sn doping reaches a maximum carrier density (1.52 × 10 21 cm − 3) at 10 at. % in ITO nanoparticles, which was estimated from the bulk plasmon energy based on a scanning ellipsometry (SE) simulation. Interestingly, the X-ray photoelectron emission spectra (XPS) of In 3d core levels show a clear asymmetric peak with a shoulder on the high-binding-energy side for degenerated ITO nanoparticles, which may be associated with the influence of the surface plasmon or plasmonic coupling. Our results suggest that combining the SE simulation and XPS measurements effectively provides a new way to understand the difference between bulk plasmons and surface plasmons for transparent conductive oxide nanoparticles. [ABSTRACT FROM AUTHOR]

The article discusses a groundbreaking research study on the precise design of titanium (Ti) sites for catalytic oxidation reactions. The researchers achieved the precise location of highly accessible and active TiO6 single sites on the mesopore surface using an innovative method involving monitoring the electrostatic interface during the synthesis of mesoporous materials. The study found that TiO6 sites have superior activity in the oxidation of certain alkenes and thiophenic sulfurs compared to TiO4 sites. The developed mesoporous titanium silicate materials exhibited extraordinary oxidative desulfurization (ODS) performance, achieving complete removal of thiophenic sulfurs from model fuels. The study highlights the potential for sustainable industrial processes with highly enhanced efficiency. [Extracted from the article]

Herein, phytosynthesized copper doped cerium oxide nanoparticles (NPs) are synthesized and their application potential in antibacterial activity is investigated. The compensative effect of Cu2+ occupying Ce4+/Ce3+ site and redox conversion of Ce4+ to Ce3+ are found to facilitate the antibacterial activity of the doped NPs. The preliminary characterizations are done using X‐ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, and energy‐dispersive analysis of X‐ray spectroscopy. The particle size distribution curves from field‐emission scanning data give the mean particle sizes to be ≈20.4, 19.9, and 18.8 nm, respectively, for pure, lightly doped, and heavily doped NPs. The transmission electron microscopy manifests tetra‐ and hexa‐shaped particles, indicating the presence of Ce2O3/Ce1−xCuxO2 along with ceria in pure and lightly doped and an additional presence of CuO in the heavily doped. The X‐ray photoelectron spectra of Ce 3d deconvolute to 10 peaks corresponding to Ce3+ and Ce4+ yielding Ce3+/Ce4+ % ratio <1 and Cu 2p and O 1s spectra are fitted to assess variation in Cu% and oxygen vacancies with doping. The Cu‐doped CeO2 samples show a commendable improvement over pure ceria, in the antibacterial activity against pathogenic bacteria Escherichia coli, Staphylococcus aureus, and Bacillus cereus. [ABSTRACT FROM AUTHOR]

Surface atomic arrangement and physical properties of aluminum ultrathin layers on c-Si(111)-7 × 7 and hydrogen-terminated c-Si(111)-1 × 1 surfaces deposited using molecular beam epitaxy were investigated. X-ray photoelectron spectroscopy spectra were collected in two configurations (take-off angle of 0° and 45°) to precisely determine the surface species. Moreover, 3D atomic force microscopy (AFM) images of the air-exposed samples were acquired to investigate the clustering formations in film structure. The deposition of the Al layers was monitored in situ using a reflection high-energy electron diffraction (RHEED) experiments to confirm the surface crystalline structure of the c-Si(111). The analysis of the RHEED patterns during the growth process suggests the settlement of aluminum atoms in Al(111)-1 × 1 clustered formations on both types of surfaces. The surface electrical conductivity in both configurations was tested against atmospheric oxidation. The results indicate differences in conductivity based on the formation of various alloys on the surface. [ABSTRACT FROM AUTHOR]

In the present work, we have systematically investigated the microstructure, optical, and photocatalytic properties of Ce1−xGdxO2 (0 ≤ x ≤ 0.20) nanostructures. All samples were synthesized using the sol–gel combustion method and characterized by various analytical techniques. The Rietveld refined x-ray diffraction (XRD) patterns confirm face-centered cubic (fcc) fluorite structure of CeO2 with Fm-3m space group in which Ce atom is located at the 4a position surrounded by the eight O (located at 8b) positions. It also endorses the incorporation of Gd3+ at the Ce3+/Ce4+ site by keeping the same crystal structure. The FTIR spectroscopy ensures bending/stretching vibrational modes associated with the functional groups at different wavenumbers. The average particle sizes from transmission electron microscopy (TEM) images for pristine and 7% Gd-doped samples are found to be 14 nm and 30 nm, respectively. X-ray photoelectron spectra (XPS) predict the electronic states, bond energies, suitable stoichiometry, and oxidation states of the compositions. The XPS spectra of Ce 3d, O 1s, and Gd 4d exhibit the creation of oxygen vacancies to maintain the charge neutrality when Ce4+ changes to Ce3+. The UV–visible data analysis shows significant variation in the bandgap (2.21–2.84 eV) as the Gd content increases in CeO2. However, a decrease in photoluminescence intensity is related to the changes in oxygen vacancies responsible for the electron–hole recombination rate. The effect of Gd doping on the properties of CeO2 is discussed on the basis of the defects and oxygen vacancies. The photocatalytic activity shows an increase in the degradation of MB dye with the increase in Gd concentration and the maximum degradation is observed as 87.72% for the 20% Gd-doped CeO2. [ABSTRACT FROM AUTHOR]

In order to reduce the noble metal palladium dosage in the preparation of CL-20 so as to reduce its production cost, several carbon supports were prepared successfully using the hydrothermal carbonization method in the absence or presence of urea using microcrystalline cellulose (MC) as the carbon source, and the corresponding Pd(OH)2/C catalysts were fabricated using the deposition–precipitation method, which showed high activity in the debenzylation reaction of hexabenzylhexaazaisowurtzitane (HBIW) and tetraacetyldibenzylhexaazaisowurtzitane (TADB). It was found that all the catalysts showed a high efficiency in the debenzylation of HBIW, indicating that the structure of the used carbon supports had a limited impact on the catalyst performance in this reaction. On the contrary, the activities of the catalysts in the debenzylation of TADB were quite different. The results of the nitrogen sorption isotherm measurement (BET), scanning electron microscope (SEM), scanning transmission electron microscopy (STEM), powder X-ray diffraction (XRD), element analysis and temperature programmed desorption (TPD), as well as X-ray photoelectron spectra (XPS) characterizations of the supports and catalysts, showed that the relatively high activity of Pd/HTC in the debenzylation of TADB was related to the high Pd dispersion and novel mesoporous structure, while the further higher activity and stability of Pd/HTC-N1:1 in the same reaction were related with its high Pd dispersion, high total oxidized Pd species, and high surface pyridinic N contents as well as the eggshell distribution of Pd species on the support. [ABSTRACT FROM AUTHOR]

Coal is a readily available and inexpensive material. However, its direct use as a catalyst is still rare, but attractive for practical application. In this paper, coal was directly used as a catalyst for the selective oxidative dehydrogenation of propane to propene. It exhibited a high selectivity over 90% with a yield of 8.4% at a high space velocity (12,000 mL·(h·g-cat)−1). The productivity up to 2.84 gC3H6 gcat−1 h−1 was obtained with propene selectivity above 80% (20,000 mL·(h·g-cat)−1). The kinetic showed first-order dependence with respect to propane or oxygen partial pressures. Meanwhile, electron paramagnetic resonance (EPR) and X-ray photoelectron spectrum (XPS) demonstrated that the carbonyl groups act as active sites for oxidative dehydrogenation of propane to propene. This work expands the use of earth-abundant and low-price coal in catalysis with expectable scale application. [ABSTRACT FROM AUTHOR]

Co3O4 catalysts modified with SrCO3 with various Sr:Co molar ratios were synthesized by a co-precipitation method and their catalytic behavior was examined for the gas-phase oxidation of vinyl chloride. The physical-chemical properties of the samples were thoroughly characterized by means of ICP-AES, BET measurements, XRD, H2-TPR, XPS and SEM-EDX. The obtained results revealed that the incorporation of strontium carbonate introduced changes in the textural and structural properties as well as modifications in the surface chemical composition of the catalysts. The performance of the samples was found to be controlled by the concentration of active species on the surface (Co2+/Co3+ and Oads/Olatt ratios) and the reducibility of the samples. As for the stability of the catalysts, clear evidences of deactivation (more severe when increasing the SrCO3 content) were noticed, probably caused by the decomposition of the SrCO3 phase and the formation of SrCl2 accompanied by a loss of textural properties and active surface oxygen species. [ABSTRACT FROM AUTHOR]

Sodium-ion batteries (SIBs) are potential replacements for lithium-ion batteries owing to their comparable energy density and the abundance of sodium. However, the low potential and low stability of their cathode materials have prevented their commercialization. Prussian blue analogs are ideal cathode materials for SIBs owing to the numerous diffusion channels in their 3D structure and their high potential vs. Na/Na+. In this study, we fabricated various Fe-V-incorporated hexacyanoferrates, which are Prussian blue analogs, via a one-step synthesis. These compounds changed their colors from blue to green to yellow with increasing amounts of incorporated V ions. The X-ray photoelectron spectroscopy spectrum revealed that V3+ was oxidized to V4+ in the cubic Prussian blue structure, which enhanced the electrochemical stability and increased the voltage platform. The vanadium ferrocyanide Prussian blue (VFPB1) electrode, which contains V4+ and Fe2+ in the Prussian blue structure, showed Na insertion/extraction potential of 3.26/3.65 V vs. Na/Na+. The cycling test revealed a stable capacity of ~70 mAh g−1 at a rate of 50 mA g−1 and a capacity retention of 82.5% after 100 cycles. We believe that this Fe-V-incorporated Prussian green cathode material is a promising candidate for stable and high-voltage cathodes for SIBs. [ABSTRACT FROM AUTHOR]

High‐performance bilayer In2O3/IGZO thin‐film transistors (TFTs) fabricated by pulsed laser deposition are reported. The TFTs exhibit an on/off current ratio of 109, a reversed subthreshold slope (ss) of 0.08 V dec−1, and a high saturation mobility of 47.9 cm2 V−1 s−1. The reliability of the mobility values is critically validated and assessed by four‐probe measurements, the transfer‐length method, and the temperature‐dependence. X‐ray photoelectron spectra are combined with C–V measurements to characterize the interface, and the results show that a two‐dimensional electron gas (2DEG)‐like state accumulates at the In2O3/IGZO interface. However, this state only forms in the subthreshold region and does not cause the high carrier mobility in the region above the threshold. Instead, the enhanced carrier mobility results from the intrinsic high mobility of the In2O3, the smooth surface, and the low‐defect states in the In2O3/IGZO bilayer with a good percolation transport path. [ABSTRACT FROM AUTHOR]

PTCDI-C8 molecules are vapor-deposited onto reconstructed Si(100)—(2 × 1) surface under ultra-high vacuum. X-ray photoelectron spectra reveal a bond formation between oxygen atoms of the molecules' carboxylic groups and Si dangling bonds of the substrate. Following PTCDI—C8 film growth, ultraviolet photoelectron spectra show a drop in the HOMO level with respect to the Fermi level from 1.8 eV to 2.0 eV and a monotonic work function increase from 2.5 eV up to 3.3 eV. For a film thickness of 6.0 nm, a difference of 1.5 eV between the HOMO level of the film and the valence band maximum of the substrate is accomplished. [ABSTRACT FROM AUTHOR]

Propane dehydrogenation (PDH), as one of the most promising strategies for propylene synthesis, has attracted tremendous attention with the increase of shale gas exploitation. The exploration of green and sustainable catalytic materials to replace the high-price (Pt-Sn/Al 2 O 3) and environmentally unfavorable (Cr 2 O 3 /Al 2 O 3) catalysts will drive the rapid development of PDH technology. Porous carbon-based materials have been proposed as ideal PDH catalysts due to their abundant surface quinone/ketone C O groups for C-H bond activation and well-developed pore structures for mass transfer. However, the facile preparation of carbon-based catalysts with controllable surface properties and unique architectures remains a challenge. And the structure-function relationship of carbon-based catalysts in PDH is also under debate. Herein, we report a simple and efficient synthetic method to prepare the porous carbon-based PDH catalysts with cheap and readily available petroleum pitch as carbon source. The surface chemical properties and architectures of the porous carbon-based catalysts can be precisely tailored by varying the activation temperature during the synthesis process. Various characterizations including X-ray photoelectron spectra, temperature-programmed pyrolysis curves, thermogravimetric analysis and morphology observations clarify that the plentiful surface quinone/ketone C O groups and appropriate adsorption/desorption strengths of reactant/products derived from the great specific surface area are vital factors that guarantee the excellent C-H bond activation capability (propane conversion 45.6%) and alkenes selectivity (73.9%, propylene and ethylene) of the petroleum pitch-derived porous carbon catalyst. This work not only provides a promising alternative catalyst for the PDH process but also enriches the application fields of the carbon-based catalysts. [Display omitted] • The catalysts are prepared with readily available petroleum pitch as raw material. • The preparation is simple and efficient, which is conducive to mass production. • The porous carbon catalysts are efficient to catalyze the propane dehydrogenation. • PDH performance can be regulated by controlling the preparation conditions [ABSTRACT FROM AUTHOR]

A novel p-n heterostructural film photocatalyst of oriented NiS/TiO2 nanosheets arrays was designed and successfully fabricated via a simple spin coating technique and its photodegradation activities of hydrogen (H2) evolution were investigated in detail. The physical and chemical properties of the as-obtained NiS/TiO2 nanosheets samples were investigated by a variety of analytical techniques such as X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), Raman, UV–Vis spectra, photoluminescence (PL), N2 adsorption–desorption and X-ray photoelectron spectra (XPS). Combining p-type NiS with n-type TiO2 nanosheets to construct distributed p-n heterojunctions, the absorption edge of NiS/TiO2 red-shifted to about 481 nm and its photoresponse in visible range significantly enhanced and the optical band gap in reduced from 3.14 to 2.55 eV. The 10-NiS/TiO2 composite films showed higher surface area (112.3 m2/g) than compared with pristine NiS (66.5 m2/g) and TiO2 (77.1 m2/g). The optimum NiS loading content was found to be 10 wt% and the corresponding hydrogen production rate is ca.7481.1 μmolh−1 g−1, being about 17 times higher than that of pure TiO2 (450.4 μmolh−1 g−1). Correlation analysis suggests that the excellent H2 photocatalytic activity of the NiS/TiO2 p-n heterostructures would stem from the synergy effects between the high efficient charge separation and transfer driven by the built-in electric field at interfaces of NiS/TiO2. [ABSTRACT FROM AUTHOR]

In this study, cotton e-textiles were obtained using two types of graphene oxide. The first type of graphene oxide was synthesized using the Hummers' method. The second type was obtained by the electrochemical exfoliation of graphite in an ammonium salt solution. It was shown that e-textiles based on electrochemically exfoliated graphene have a higher electrical conductivity (2 kΩ/sq) than e-textiles based on graphene oxide obtained by the Hummers' method (585 kΩ/sq). In addition, textiles based on electrochemically exfoliated graphene exhibit better washing and mechanical stress stability. The electrical resistance of the e-textiles increased only 1.86 times after 10 cycles of washing, compared with 48 times for the Hummers' method graphene oxide textiles. The X-ray photoelectron spectra of the two types of graphene oxides showed similarity in their functional compositions after reduction. Studies of individual graphene flakes by atomic force microscopy showed that graphene oxide of the second type had a smaller lateral size. Raman spectroscopy showed a higher degree of sp2 structure regeneration after reduction for the second type of graphene. These properties and the tendency to form agglomerated particles determine the mechanochemical stability and high electrical conductivity of e-textiles based on electrochemically exfoliated graphene. [ABSTRACT FROM AUTHOR]

Carbon xerogels co-doped with nitrogen (N) and phosphorus (P) or sulfur (S) were synthesized and employed as catalysts for the electrocatalytic reduction of p-nitrophenol (p-NP). The materials were prepared by first synthesizing N-doped carbon xerogels (NDCX) via the pyrolysis of organic gels, and then introducing P or S atoms to the NDCX by a vapor deposition method. The materials were characterized by various measurements including X-ray diffraction, N2 physisorption, Transmission electron microscopy, Fourier Infrared spectrometer, and X-ray photoelectron spectra, which showed that N atoms were successfully doped to the carbon xerogels, and the co-doping of P or S atoms affected the existing status of N atoms. Cyclic voltammetry (CV) scanning manifested that the N and P co-doped materials, i.e., P-NDCX-1.0, was the most suitable catalyst for the reaction, showing an overpotential of −0.569 V (vs. Ag/AgCl) and a peak slop of 695.90 μA/V. The material was also stable in the reaction and only a 14 mV shift in the reduction peak overpotential was observed after running for 100 cycles. [ABSTRACT FROM AUTHOR]

Due to people's pursuit of healthy and green life, soy protein isolate (SPI) is occupying a larger and larger market share. However, the low solubility of SPI affects its development in the field of food and medicine. This paper aimed to investigate the effects of sodium trimetaphosphate (STMP) on the functional properties and structures of phosphorylated SPI and its lutein‐loaded emulsion. After modification by STMP, the phosphorus content of phosphorylated SPI reached 1.2–3.61 mg/g. Infrared spectrum and X‐ray photoelectron spectrum analysis confirmed that PO43− had phosphorylation with –OH in serine of SPI molecule. X‐ray diffraction analysis showed that phosphorylation destroyed the crystal structure of protein molecules. Zeta potential value of phosphorylated SPI decreased significantly. When STMP addition was 100 g/kg, particle size of protein solution decreased to 203 nm, and solubility increased to 73.5%. Furthermore, emulsifying activity and emulsifying stability increased by 0.51 times and 8 times, respectively. At the same protein concentration (1%–3% [w/w]), lutein‐loaded emulsion prepared by phosphorylated SPI had higher absolute potential and smaller particle size. The phosphorylated protein emulsion at 2% concentration had the best emulsion stability after storage for 17 days. Practical Application: Phosphorylation significantly improved the emulsifying properties and solubility of SPI. Phosphorylated SPI significantly improved the stability of lutein‐loaded emulsion. It provides theoretical basis for the application of phosphorylated SPI as emulsifier in delivery system and broadens the development of lutein in food and medicine field. [ABSTRACT FROM AUTHOR]

Coal thermochemical conversion processes unavoidably generate gaseous pollutants, endangering the environment or influencing synthetic processes downstream. In order to display the differences in release behaviours of nitrogen among different coal thermochemical conversion stages, the nitrogen release characteristics of Shenhua bituminous coal under Ar, CO2, and air atmospheres were investigated using X‐ray photoelectron spectrum (XPS) and thermogravimetry‐mass spectrometry (TG‐MS). Results indicate that the reaction atmosphere has an important influence on nitrogen release. The total released mass of nitrogen when using 100 g raw coal in the whole experiment under Ar, CO2, and air atmospheres is 0.54, 0.64, and 0.75 g, respectively. The organic forms of nitrogen in raw coal and coal char are pyridine nitrogen (N‐6), pyrrole nitrogen (N‐5), quaternary nitrogen (N‐Q), and nitrogen oxide (N‐X). While in the coal ash, the sub‐peaks of N‐Q and N‐X disappear entirely, leaving only N‐5 and N‐6 sub‐peaks. The released nitrogen‐containing gas consists of NH3, HCN, NO, and NO2 during experiments in CO2 and air atmospheres. However, only NH3 and HCN are detected during experiments in the Ar atmosphere. The revolution characteristics of NH3 and HCN under Ar and CO2 atmospheres are similar. [ABSTRACT FROM AUTHOR]

Activated carbons (AC) play a key role in enabling the reaction kinetic of cathodes in lithium ion batteries (LIBs). However, the charge transfer dynamics and reaction kinetics mechanism of AC composited cathodes along their thickness direction are still poorly understood. Herein, we systematically compare the internal reactive process evolutions of AC modified LiNi 0.6 Co 0.2 Mn 0.2 O 2 (NCM622) cathodes and pristine NCM622 cathodes at high C-rates. The charge transfer dynamic is revealed by the time of flight secondary ion mass spectrometry and X-ray photoelectron spectra analyzes. The addition of AC endows the NCM622 cathode regions close to the current collector possess higher lithium ion concentrations, meanwhile more Ni2+ can be converted into Ni3+. The results of COMSOL Multiphysics simulations based on the porous electrode theory is analyzed to explore reaction kinetics mechanism. AC in NCM622 cathodes homogenizes the reaction distributions, contributing to the boosted reaction kinetic, eventually, resulting in the high utilization of active materials. These findings provide a direct way to reduce solid-state diffusion resistances and accelerate reaction kinetics of electrodes, which is critical for developing batteries with long cycle stability and rate performance at high rates. [Display omitted] [ABSTRACT FROM AUTHOR]

In this work, a core‐shell structured magnetic covalent organic framework (Fe3O4@TpPDA) was synthesized through simple in‐situ growth method by using 1,3,5‐triformylphloroglucinol (Tp) and 1,4‐phenylenediamine (PDA) as precursors, and used as adsorbents for the efficient adsorption and removal of Congo red from aqueous solution. The as‐prepared Fe3O4@TpPDA was characterized by Fourier transform infrared spectroscopy, X‐ray powder diffraction, X‐ray photoelectron spectroscopy spectra and transmission electron microscopy. The influence of initial concentration, adsorption time, and temperature was evaluated. The adsorption of Congo red onto Fe3O4@TpPDA was investigated by adsorption models including Langmuir, Freundlich, pseudo‐first‐order and pseudo‐second‐order kinetic models. The adsorption behavior was fitted well with the Langmuir isotherm and consistent with the pseudo secondary dynamics model. The maximum adsorption capacity was found to be 179.4 mg/g. According to thermodynamic analysis, Congo red adsorption is a spontaneous endothermic reaction. Furthermore, the reusability of Fe3O4@TpPDA was determined by recycling it up to seven times. Thus, Fe3O4@TpPDA was considered to be an excellent adsorbent for the quick and efficient adsorption of Congo red from environmental water. [ABSTRACT FROM AUTHOR]

Herein, we first design a model of reversible redox‐switching metal–organic framework single‐unit‐cell sheets, where the abundant metal single sites benefit for highly selective CO2 reduction, while the reversible redox‐switching metal sites can effectively activate CO2 molecules. Taking the synthetic Cu‐MOF single‐unit‐cell sheets as an example, synchrotron‐radiation quasi in situ X‐ray photoelectron spectra unravel the reversible switching CuII/CuI single sites initially accept photoexcited electrons and then donate them to CO2 molecules, which favors the rate‐liming activation into CO2δ−, verified by in situ FTIR spectra and Gibbs free energy calculations. As an outcome, Cu‐MOF single‐unit‐cell sheets achieve near 100 % selectivity for CO2 photoreduction to CO with a high rate of 860 μmol g−1 h−1 without any sacrifice reagent or photosensitizer, where both the activity and selectivity outperform previously reported photocatalysts evaluated under similar conditions. [ABSTRACT FROM AUTHOR]

In this work, adsorbents based on hydrochars and steam activated hydrochars developed from flax shives were used to adsorb carbamazepine (CBZ) from simulated contaminated water. The adsorption kinetics was investigated at various temperatures (293–313 K) and times (2–96 h). Four different kinetic models were used to analyze the experimental CBZ adsorption kinetic data. Among the tested various models, the pseudo-second-order kinetic model provided the best simulation to the kinetic data of both adsorbents with R2 of being 0.98 and above, and activation energy of 31.8 and 16.45 kJ/mol, respectively. The determined adsorption rate constant of the steam activated hydrochars ((5.88–9.09) × 10−5) was much higher than that of the hydrochars ((2.81–6.44) × 10−6). Further, X-ray photoelectron spectra and Near-Edge X-Ray Absorption Fine Structure (NEXAFS) Spectroscopy analysis were done before and after loading with CBZ. The results show π-π electron donor-acceptor interaction played an important role on the adsorption mechanism of CBZ on the above-mentioned adsorbents. Hydrophobic interaction also contributed while the roles of hydrogen bonding and electrostatic attraction between CBZ and adsorbents with opposite charges is insignificant. Pore filling may contribute. Desorption of CBZ from CBZ-loaded adsorbents was investigated with various organic solvents, and water at different pH (2, 6 and 10), among which ethanol was the most effective solvent to desorb CBZ. Overall, the results demonstrated that flax shives are promising feedstocks to be made into adsorbents for treatment of wastewater contaminated by antibiotics and additional pharmaceuticals. [Display omitted] • Flax shive adsorbents were used to adsorb carbamazepine (CBZ). • The adsorption kinetics was investigated at various temperatures and times. • The mechanisms of CBZ adsorption were elucidated. • Desorption of CBZ from CBZ-loaded adsorbents was investigated with various organic solvents and water at different pH. [ABSTRACT FROM AUTHOR]

Transition metal carbonitrides (MXenes) are promising catalysts due to their special structures. Recently, many studies have shown that MXenes have a catalytic effect on the thermal decomposition of ammonium perchlorate (AP). However, the catalytic effects have not been extensively investigated. Therefore, it is important to illustrate the catalytic mechanisms of pure MXene in AP thermal decomposition. Herein, the catalytic properties of Ti2CTx for ammonium perchlorate (AP) thermal decomposition were investigated by numerous catalytic experiments. The results showed that the high-temperature decomposition (HTD) decreased by 83 °C, and the decomposition heat of AP mixed with Ti2CTx increased by 1897.3 J/g. Moreover, the mass spectrum (MS) data showed that the NH3, H2O, O2, N2O, NO, HCl, and NO2 were formed. In addition, according to the X-ray diffraction (XRD), Raman spectrum, high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), and X-ray photoelectron spectra (XPS) results, the Ti2CTx nanosheets can adsorb the gaseous products and react with them in-situ, generating anatase-TiO2 and carbon layers. The Ti2CTx, as-resulted anatase-TiO2, and carbon can synergize and further catalyze the thermal decomposition of AP when both electron and proton transfers are accelerated during AP decomposition. [ABSTRACT FROM AUTHOR]

The derivatization of graphene to engineer its band structure is a subject of significant attention nowadays, extending the frames of graphene material applications in the fields of catalysis, sensing, and energy harvesting. Yet, the accurate identification of a certain group and its effect on graphene's electronic structure is an intricate question. Herein, we propose the advanced fingerprinting of the epoxide and hydroxyl groups on the graphene layers via core-level methods and reveal the modification of their valence band (VB) upon the introduction of these oxygen functionalities. The distinctive contribution of epoxide and hydroxyl groups to the C 1s X-ray photoelectron spectra was indicated experimentally, allowing the quantitative characterization of each group, not just their sum. The appearance of a set of localized states in graphene's VB related to the molecular orbitals of the introduced functionalities was signified both experimentally and theoretically. Applying the density functional theory calculations, the impact of the localized states corresponding to the molecular orbitals of the hydroxyl and epoxide groups was decomposed. Altogether, these findings unveiled the particular contribution of the epoxide and hydroxyl groups to the core-level spectra and band structure of graphene derivatives, advancing graphene functionalization as a tool to engineer its physical properties. [ABSTRACT FROM AUTHOR]

The plasma pyrolysis and plasma catalysis of methane coupling were performed under room temperature and atmosphere. The coupling of methane through gliding arc plasma with different H 2 /CH 4 ratios and N 2 flow rates exhibited conversion from 25% to 40% and high selectivity of acetylene above 90%. Plasma emission spectra displayed lowest I Hβ /I Hα ratio at H 2 /CH 4 ratio of 3, while I Hβ /I Hα ratio decreased with increasing N 2 feed rate from 0 to 2 L/min, which had similar variation with selectivity of acetylene. X-ray photoelectron spectra for reduced catalysts demonstrated that metallic Pd species (335.4 eV) were transferred to electron-rich Pd species (334.8eV and 334.1 eV) with increasing Pd loading and Ag/Pd ratio, corresponding to red shift of linear adsorbed CO stretching frequency from 2060 to 2068 cm−1 to 2055-2015 cm−1. Superior plasma catalytic behavior over 0.1Pd0.5Ag/Al 2 O 3 catalyst has been reached with 86.5% selectivity of ethene and 36.2% conversion of methane. • Methane coupling to ethene can achieve high yield of 30.2% through plasma catalysis. • Gliding arc plasma made high gas temperature leading to more acetylene production. • Proper AgPd catalyst exhibited great suitability for plasma catalysis process. [ABSTRACT FROM AUTHOR]

Graphitic carbon nitride (g-C3N4) has received much interest as a visible-light-driven photocatalyst for degrading pollutants such as organic dyes and antibiotics. However, g-C3N4 bulk activity could not meet expectations due to its rapid recombination of photogenerated electron–hole pairs and low specific surface area. In our study, melamine was thermally treated one-step in the presence of NH4Cl to produce g-C3N4 nanosheets. The characterizations of surface morphology and optical properties of all g-C3N4 samples were investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectrum (XPS), transmission electron microscopy (TEM), and UV–visible diffuse reflectance spectroscopy. Compared to bulk g-C3N4, g-C3N4 nanosheets demonstrated excellent photocatalytic activities, with approximately 98% RhB removal after 210 min of visible light irradiation. Furthermore, the effect of catalyst dosage, pH, and RhB concentration on the removal percentage dye of g-C3N4 nanosheets was also investigated. h+ and •O2− species were demonstrated as the key reactive species for the RhB. Besides, ECN exposed a tetracycline degradation efficiency of 80.5% under visible-light irradiation for 210 min, which is higher than BCN (60.8%). The improved photocatalytic activity of g-C3N4 nanosheets is due to the restriction of the recombination of photogenerated electrons/hole pairs, as provided by photoluminescence spectra and Nyquist plot. As a result, our research may offer an effective approach to fabricating g-C3N4 nanosheets with high photocatalytic activity and high stability for environmental decontamination. [ABSTRACT FROM AUTHOR]

Towards solving the poor electrochemical performance of LiCoPO 4 as a cathode in Lithium-ion batteries, here we propose a novel durable one-pot technique. Mil-88a metal-organic framework (MOF) nanoparticles have been incorporated through LiCoPO 4 synthesis to form a metal-carbon layer after calcination. The structure of our novel cathode has been investigated using XRD, XRF, and TEM. The TEM images showed that the increase in the concentration of Mil-88a to 3% and annealed under air led to forming of a homogeneously distributed shell layer from porous carbon and doped with iron oxide nanoparticles (10–40 nm). The X-ray photoelectron spectra of LiCoPO4@Mil-88a verifies the presence of a Fe-rich surface layer on the nanoparticle surface of LiCoPO 4. The electrochemical studies assured that the 1st cycle yielded a discharge-specific capacity of 138 mAhg−1. The Mil-88a MOF is a basis for metal atoms and carbon, increasing the bulk conductivity. [ABSTRACT FROM AUTHOR]

Variable-pressure electron-beam lithography (VP-EBL) employs an ambient gas at subatmospheric pressures to reduce charging during electron-beam lithography. VP-EBL has been previously shown to eliminate pattern distortion and provide improved resolution when patterning poly(methyl methacrylate) (PMMA) on insulating substrates. However, it remains unknown how water vapor affects the contrast and clearing dose nor has the effect of water vapor on the negative-tone behavior of PMMA been studied. In addition, water vapor has recently been shown to alter the radiation chemistry of the VP-EBL process for Teflon AF. Such changes in radiation chemistry have not been explored for PMMA. In this work, VP-EBL was conducted on conductive substrates to study the effect of water vapor on PMMA patterning separately from the effects of charge dissipation. In addition, both positive and negative-tone processes were studied to determine the effect of water vapor on both chain scission and cross-linking. The contrast of PMMA was found to improve significantly with increasing water vapor pressure for both positive and negative-tone patterning. The clearing dose for positive-tone patterning increases moderately with vapor pressure as would be expected for electron scattering in a gas. However, the onset set dose for negative-tone patterning increased dramatically with pressure revealing a more significant change in the exposure mechanism. X-ray photoelectron spectra and infrared transmission spectra indicate that water vapor only slightly alters the composition of exposed PMMA. Also, electron scattering in water vapor yielded a much larger clear region around negative-tone patterns. This effect could be useful for increasing the range of the developed region around cross-linked PMMA beyond the backscattered electron range. Thus, VP-EBL for PMMA introduces a new means of tuning clearing/onset dose and contrast, while allowing additional control over the size of the cleared region around negative-tone patterns. [ABSTRACT FROM AUTHOR]

The "battery type" inorganic electrode has been demonstrated the highly efficient sodium ion intercalation capacity for capacitive deionization. In this work, the CoMn2O4 (CMO) microspheres with porous core‐shell structure are prepared via co‐precipitation and followed by annealing. The effects of annealing temperatures on the morphology, pore structure, valence state, and electrochemical behavior of CMO are explored. As electrode for capacitive deionization, the salt removal capacity and current efficiency of optimized AC || CMO device reaches up to 60.7 mg g−1 and 97.6%, respectively, and the capacity retention rate is 74.1% after 50 cycles. Remarkably, both the in‐situ X‐ray diffraction and ex‐situ X‐ray diffraction analysis features that the intercalation/de‐intercalation of sodium ions are governed by (103) and (221) crystal planes of CMO. Accordingly, the density functional theory calculations realize that the adsorption energies of Na+ onto (103) and (221) crystal planes are higher than that of any other crystal planes, manifesting the priorities in adsorption of sodium atoms. Furthermore, the X‐ray photoelectron spectra of pristine and post‐CMO electrode highlights that the reversible conversion of Mn3+/Mn4+ couple is resulted from the intercalation/de‐intercalation of Na+, while this is irreversible for Co3+/Co2+ couple. Beyond that, the CMO electrode has been proven the selectivity removal of Na+ over K+ and Mg2+ in a multi‐cation stream. [ABSTRACT FROM AUTHOR]

In optical crystals, photodarkening will occur after they were irradiated with high-energy particles, and such induced optical loss generally results in significant performance degradation whether they are used as passive or active optical elements. In the present study, the effects of neutron irradiation on the optical response of the Nd3+-doped Gd3Sc2Al3O12 (Nd:GSAG) single crystal has been revealed in real-time and in-situ. Transient and permanent transmittance reduction in the crystal induced by neutron radiation has been observed and the reduction mechanisms have been analyzed. The XRD characterization method demonstrated that the crystal structure remained constant both before and after neutron irradiation. Importantly, the X-ray photoelectron peak of the O 1s core level shifts to high binding energy, indicating that oxygen vacancies were produced in the crystal after irradiation with neutrons. Thus, the permanent reduction in the transmittance of the crystal after irradiation with neutrons can be attributed to the generation of oxygen vacancies in the crystal. To the best of our knowledge, it is the first time the damage types in rare earth oxide laser crystals caused by neutron irradiation were revealed. [ABSTRACT FROM AUTHOR]

We investigated the adsorption of silver(I) from silver nitrate (AgNO3) and silver sulphate (Ag2 SO4). We compared the adsorption ability of chitosan in the form of hydrogel beads with that of chitosan acetate - an initial solution from which the beads were derived. We developed a model of adsorption kinetics, assuming the simultaneous occurrence of the diffusion process and the chemical reaction. We confirmed and described the chemical nature of adsorption based on the Fourier-transform infrared and X-ray photoelectron spectra. [ABSTRACT FROM AUTHOR]

Exposure to ultraviolet radiation induces photodamage towards cellular macromolecules that can progress to photoaging and photocarcinogenesis. The topical administration of compounds that maintain the redox balance in cells presents an alternative approach to combat skin oxidative damage. Cerium oxide nanoparticles (CNPs) can act as antioxidants due to their enzyme-like activity. In addition, a recent study from our group has demonstrated the photoprotective potential of tannic acid (TA). Therefore, this work aimed to synthesize CNPs associated with TA (CNP-TA) and investigate its photoprotective activity in L929 fibroblasts exposed to UVB radiation. CNP conjugation with TA was confirmed by UV–Vis spectra and X-ray photoelectron spectroscopy. Bare CNPs and CNP-TA exhibited particle sizes of ~5 and ~10 nm, superoxide dismutase activity of 3724 and 2021 unit/mg, and a zeta potential of 23 and −19 mV, respectively. CNP-TA showed lower cytotoxicity than free TA and the capacity to reduce the oxidative stress caused by UVB; supported by the scavenging of reactive oxygen species, the prevention of endogenous antioxidant system depletion, and the reduction in oxidative damage in lipids and DNA. Additionally, CNP-TA improved cell proliferation and decreased TGF-β, metalloproteinase-1, and cyclooxygenase-2. Based on these results, CNP-TA shows therapeutic potential for protection against photodamage, decreasing molecular markers of photoaging and UVB-induced inflammation. [ABSTRACT FROM AUTHOR]

[Display omitted] • The study confirmed the (−101) plane as the twin symmetric plane to the (001) plane in β-Ga 2 O 3. • The (−101) plane has two termination form with 1.614 × 1015/cm2 and 2.421 × 1015/cm2, respectively. • Its defect morphologies different from that of (001) plane. • The low Schottky barrier height Φsurf of 1.12 eV means easy to ohmic contact. This study confirms that the symmetric plane of (001) with respect to the twin boundary in β-Ga 2 O 3 is the ( 1 ¯ 01), and it has been systematically characterized. X-ray diffraction has determined that diffraction peaks appear only at positions where the l component of the miller indices hkl is even, and these positions coincide with the diffraction peak positions of the (001) plane. The termination atomic arrangement of the ( 1 ¯ 01) plane is not exclusively composed of gallium or oxygen atoms, it exists in two forms with hanging bond densities of 1.614 × 1015/cm2 and 2.421 × 1015/cm2, respectively. Wet etching experiments on the ( 1 ¯ 01) plane reveal distinct defect morphologies compared to the (001) plane, indicating its suitability for distinguishing between these two planes. The Raman modes of ( 1 ¯ 01) plane coincide with other crystal planes. Through optical transmission spectra, X-ray photoelectron spectra, and Ultraviolet photoelectron spectra, its bandgap width E g of 4.76 eV, the valence band maximum E VBM of 3.64 eV and the Schottky barrier height Φ surf of 1.12 eV were determined. Compared to studies of other crystal planes, it is believed that the ( 1 ¯ 01) plane also possesses similar application potential. [ABSTRACT FROM AUTHOR]

• Dependence of crystallite size and morphology of nanocrystalline ZnO on synthesis temperature. • Defect dominated photoluminescence spectra and its assignment. • Dependence of photocurrent response on crystallite size and its wavelength dependence. • Dependence of photocatalytic activity and reuse on crystallite size. Nanocrystalline zinc oxide (ZnO) samples are synthesized through a facile hydrothermal route at different temperatures. Sample synthesized at 80 °C (sample code HT80) has average crystallite size of 32 ± 2 nm and the morphology is not unform with the presence of rods, wires and discs. Sample prepared at 160 °C (sample code HT160) has rod-like morphology with an average crystallite size of 130 ± 5 nm. X-ray photoelectron spectra reveal the presence of hydroxyl groups bonded to Zn2+, oxygen vacancies and adsorbed oxygen species in both the samples. Atomic percentage of the bonded/adsorbed hydroxides and oxygen containing species is higher in HT80. Band gaps values are lower in comparison with bulk ZnO due to band bending. Photoluminescence spectra has a UV peak at ∼381 nm (3.25 eV) and a broad emission band in the visible region centred at ∼550 nm (2.25 eV) respectively corresponding to the band edge emission and defect mediated emission. The emission profile of both samples is similar indicating the presence of similar type of native point defects viz., Zn vacancies, Zn interstitials and oxygen vacancies in different charge states. Sample HT160 has more intense emission due to the better photonic absorption. The photocurrent response under wide light irradiation is also larger for HT160 with a sensitivity of 37 due to the better photonic absorption and larger crystallite size. Wavelength dependent photocurrent response for this sample shows highest sensitivity at 380 nm with a sensitivity of 152 corresponding to the band-to-band excitation. A weak photoresponse for visible light irradiation (∼600 nm) due to the desorption of adsorbed O 2 or hydroxide species caused by the direct photoexcitation of the captured electron to the conduction band is also noted. Photocatalytic efficiency of both the samples are comparable with rate constants 3.1 × 10−2 min−1 and 3.7 × 10−2 min−1 respectively for HT80 and HT160. The reusability is much better for sample HT160 which is attribute to larger average crystallite size and uniform morphology. [ABSTRACT FROM AUTHOR]

• Nano-sized Bi 2 Ti 2 O 7 was successfully prepared by glass powder crystallization. • The best heat treatment process was held at 628 °C for 70 min. • The degree of crystal exposure has a great influence on photocatalytic efficiency. • The photocatalytic efficiency of pickled glass-ceramics is higher. The low-cost glass-ceramics catalyst can promote the application of photocatalysis technology in water pollution treatment. This study successfully synthesized cost-effective glass-ceramics containing nano-sized spherical Bi 2 Ti 2 O 7 through a glass powder crystallization method. The photocatalytic efficiency of glass-ceramics catalyst prepared by different crystallization processes was evaluated by RhB dye. Furthermore, the factors affecting the photocatalytic efficiency of glass-ceramics were analyzed by crystallization mechanism, transmission electron microscope (TEM) and X-ray photoelectron spectra (XPS). Under visible light irradiation, the glass-ceramics catalyst prepared by the best crystallization process can achieve photocatalytic degradation rate of 99.3 % within 300 min. This study shows that glass-ceramics catalyst can be rendered as one of the most suitable candidates for photocatalytic degradation of organic pollutants. [ABSTRACT FROM AUTHOR]

Herein, we demonstrate a novel and feasible strategy to stabilize the LiNi 0.83 Co 0.12 Mn 0.05 O 2 (NCM) structure via the in-situ formation of a superficial spinel layer with potassium (K) doping. While K+ doped NCM is not new, the formation of the protective spinel layer gives surprising results with even a trace amount of doping, which is unique and novel, and nowhere reported. The structural transformation from layered to spinel on the surface region of NCM is achieved with a K-doping level of 0.05 mol% (NCM-0.05K) and the formed spinel layer acted as a protective pillar for stabilizing the host structure, leading to substantially improved electrochemical performance. The X-ray photoelectron spectra demonstrate a large increase in nickel (Ni2+) distribution after cycling for pristine but almost no change for the NCM-0.05K, suggesting a stable preformed spinel layer. The above results reveal that the K+ doping can strongly reduce the Ni4+ to stable Ni2+ under the spinel phase formation and improves cell performances in terms of specific capacity, capacity retention, rate capability, and Li+ diffusivity. The internal micro-cracking of host NCM is also effectively suppressed by the low amount of K doping. Excessive K-doping, in contrast, leads to a reduction in (de)lithiation rate and greater polarization. • An in-situ formation of a passive spinel layer through a trace amount of K+ doping. • K+-doping improves the structure stability of the Ni-rich NCM. • K-NCM shows excellent Li+-diffusive properties than pristine-NCM. • K-NCM also suppresses the internal micro-cracking. [ABSTRACT FROM AUTHOR]

Transition metal oxide (TMO) thin films exhibit large bandgap and hold great potential for enhancing the performance of silicon heterojunction (SHJ) solar cells by increasing the short-circuit current density significantly. On the other hand, achieving precise control over the electrical properties of TMO layers is crucial for optimizing their function as efficient carrier-selective layer. This study demonstrates a general and feasible approach for manipulating the quality of several TMO films, aimed at enhancing their applicability in silicon heterojunction (SHJ) solar cells. The core of our method involves precise engineering of the interface between the TMO film and the underlying hydrogenated intrinsic amorphous silicon passivation layer by managing the reaction of the TMO on the surface. X-ray photoelectron spectroscopy spectra demonstrate that our methods can modify the oxygen content in TMO films, thereby adjusting their electronic properties. By applying this method, we have successfully fabricated WO x -based SHJ solar cells with 23.30 % conversion efficiency and V 2 O x -based SHJ solar cells with 22.04 % conversion efficiency, while keeping n -type silicon-based electron-transport layer at the rear side. This research paves the way for extending such interface engineering methods to other TMO materials used as hole-transport layers in SHJ solar cells. • Controlling the TMO/(i)a-Si:H interface using three methods: noPT, PT, and PTB. • PT method preserves oxygen content in TMO layers better than PTB and noPT methods. • PTB method maintains optimal TMO oxygen content regarding conversion efficiency. • PTB method enables 23.30 % efficiency and 80.80 % FF in WO x -based SHJ solar cells. • PTB method enables 22.04 % efficiency and 74.88 % FF in V 2 O x -based SHJ solar cells. [ABSTRACT FROM AUTHOR]

A new 3D octamolybdate-based metal–organic complex was synthesized by using a rigid nitrogen heterocyclic carboxylic acid ligand 1-(4-carboxyphenyl)-3-(pyrazine-2-yl)-pyrazole. It displays good electrocatalysis reduction activities toward BrO 3 − and NO 2 − and can be used as a nitrite amperometric sensor. In addition, its photocatalytic degradation and antibacterial properties have also been investigated. [Display omitted] • An octamolybdate-based metal–organic complex was synthesized using a rigid nitrogen heterocyclic carboxylic acid ligand. • The compound displays good electrocatalysis reduction activities and can be used as a nitrite amperometric sensor. • The compound has good photocatalytic efficiency for MB, MO and RhB. • The antibacterial properties were investigated. The hydrothermal reaction of 1-(4-carboxyphenyl)-3-(pyrazine-2-yl)-pyrazole (HX) with AgNO 3 in the presence of [PMo 12 O 40 ]3− anions results in a new 3D octamolybdate-based metal–organic complex, [Ag 2 (HX)(X)(H 2 Mo 8 O 26) 0.5 ]·H 2 O (1). 1 was characterized using X-ray photoelectron spectra, scanning electron microscopy, powder X-ray diffraction, elemental mapping, IR spectroscopy, thermogravimetric analysis and single-crystal X-ray diffraction. In compound 1 , [H 2 Mo 8 O 26 ]2− was in situ generated from the Keggin-type [PMo 12 O 40 ]3−. Compound 1 is a 3D framework composed of 2D metal–organic layers [Ag 2 (HX)(X)] n n+ and [H 2 Mo 8 O 26 ]2− clusters. Its electrochemical properties were investigated and the results showed that 1 could serve as an electrochemical sensor to detect NO 2 −. Compound 1 exhibits photocatalytic activity in the degradation of methylene blue, methyl orange and Rhodamine B. The mechanism of the photocatalytic degradation was also studied. Additionally, the antibacterial properties against Escherichia coli, Ralstonia solanacearum and Xanthomonas axonopodis pv. Citri were investigated. [ABSTRACT FROM AUTHOR]

The crystal chemistry of uranium sulfides is characterized by a large diversity in composition, crystal structures, oxidation states and physical properties. This holds also for TiU 8 S 17 and U 36 Lu 21 S 93 I 3 , of which large single crystals up to several mm in length were grown by chemical vapor transport using iodine as a transport agent. TiU 8 S 17 crystallizes with the monoclinic CrU 8 S 17 structure type (C 2/ m , a = 13.3477(2) Å, b = 8.4927(2) Å, c = 10.4836(2) Å, β = 101.207(2)°) featuring distorted octahedra [TiS 6 ] and bicapped trigonal prisms [US 8 ]. Interatomic distances and X-ray photoelectron spectra indicate tetravalent uranium. Disordered U 36 Lu 21 S 93 I 3 represents a new structure type (R 3 ¯ m , 13.3841(2) Å, 20.6447(2) Å) with an average crystal structure exhibiting square antiprisms [LuS 8 ], bi- and tricapped trigonal prisms [US 8 ] and [US 9 ] and distorted octahedra [IU 6 ]. Lutetium and sulfur atoms are disordered similar to Ce 53 Fe 12 S 90 X 3 , La 53 Fe 12 S 90 X 3 (X = Cl, Br, I) and La 52 Fe 12 S 90. This might be caused by positional shifts of iodine atoms away from the center of the polyhedron, thus avoiding unusually long U–I distances and severely disrupting the order of neighboring lutetium and sulfur atoms. The results of chemical analyses (ICP-MS, EDX), electron microscopy (TEM) and X-ray photoelectron spectroscopy support the composition and crystal structure of U 36 Lu 21 S 93 I 3 and indicate mixed valency of uranium and charge balance according to the crystal chemical formula (U+III) 18 (U+IV) 18 (Lu+III) 21 (S-II) 93 (I–I) 3. A combination of diffraction methods and XPS revaled the unusual structure of a new mixed-valent quaternary uranium sulfide iodide featuring a rare positional disorder of lutetium atoms. [Display omitted] • Reaction of the elements yields large single crystals of a new compound U 36 Lu 21 S 93 I 3. • A complex network of uranium-centered sulfur polyhedra exhibits two types of cavities – one for iodine, the other for sulfur. • An unusual positional disorder of Lu-atoms towards the sulfur-containing cavity is observed over five distinct positions. • XPS hints towards a mixed valency of this compound following the ionic formula (U3+) 18 (U4+) 18 (Lu3+) 21 (S2−) 93 (I−) 3. • The structure of TiU 8 S 17 is redetermined from single-crystal data and discussed in detail. [ABSTRACT FROM AUTHOR]

The development of hard magnetic properties in Nd-Fe-B films with a thickness below 50 nm has been studied and the effect of the film strain on the spin reorientation transition temperature (T SR) evaluated. A value of 35 nm is found to be the lowest thickness threshold in the films grown by DC magnetron sputtering in this study for the full development of both the Nd 2 Fe 14 B phase and the broadening of the out of plane hysteresis loops. Large perpendicular magnetic anisotropy is obtained for a film of 40 nm in thickness, reaching a coercivity of 8 kOe at room temperature. A detailed characterization of epitaxial Nd 2 Fe 14 B with high magnetic anisotropy has been done by Grazing Incidence X-Ray Diffraction, lattice parameters are reported and the chemical states of Nd 3d and Fe 2p have been stablished by the analysis of Hard X-Rays Photoelectron Spectroscopy spectra. The spin reorientation transition temperature has been estimated to a value of 124.2 K. Based on experimental results, lattice strain is attributed as the main reason for the deviation of T SR by comparison with the theoretical value (135 K). No evidence of tetragonal distortion in the lattice is found below T SR in this system in contrast to previous considerations. [Display omitted] • Magnetron sputtering is a suitable technique for the fabrication of low dimensional thin films of Nd-Fe-B (below 40 nm). • There is a minimum thickness threshold for the development of large coercivity and perpendicular magnetic anisotropy. • Optimum magnetic performance is determined by Nd 2 Fe 14 B texture and an efficient distribution of the secondary phases. • It is possible to tune the spin reorientation transition temperature of NdFeB in a thin film architecture. • Changes in spin reorientation transition temperature are associated to lattice strain in Nd 2 Fe 14 B induced during synthesis. [ABSTRACT FROM AUTHOR]