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Diamond-like carbon (DLC)/poly-α-olefin (PAO) composite system attracts much attention in reducing the tribo-induced risks for mechanical mobility systems and energy saving. However, the coupled effect of applied load and PAO viscosity on the tribological behavior of the DLC/PAO system, which normally causes the transition between different lubrication states of mated surfaces, and the corresponding synergistic mechanism remain unclear. Here, we fabricated the DLC/PAO composite system, and the evolutions of microstructure, morphologies, and tribological properties induced by both PAO viscosity and applied load were investigated systematically. Results indicated that under low applied load, the system with moderate PAO viscosity exhibited the best tribological performance, while the PAO with high viscosity was suggested with increasing the applied load. Moreover, the variations of PAO viscosity and applied load seriously affected the distribution and load-bearing capacity of oil, interfacial graphitization degree, and formation of lubricating oil film, which brought complicated effects on the tribological properties of composite systems. The present results guide the selection and design of an advanced DLC/PAO lubrication system according to the working conditions. [ABSTRACT FROM AUTHOR]

Cr doping is a new strategy to enhance the OER (Oxygen Evolution Reaction) performance of NiFe-LDH (NiFe-Layered Double Hydroxides) by optimizing surface states and offering a scalable production process. However, as an additive element, Cr itself has weak OER performance, so its promotion on the Ni- and Fe-active site by electron perturbation and structural stabilization in NiFeCr-LDH has been the focus. Herein, a one-step hydrothermal method is used to incorporate Cr into NiFe-LDH, systematically investigating the relationship between Cr content and the material's microstructure. The results of physical characterization show that Cr ion plays a leading role in the electron perturbation Ni/Fe-active center, which causes the increasing of Fe3+ and Ni3+ content. Furthermore, variations in Cr content resulted in the lattice stretching and morphology evolving synchronously. The optimized NiFeCr-LDH exhibited significantly enhanced OER activity and durability compared to undoped NiFe-LDH and outperformed commercial RuO 2 catalysts. Additionally, a microstructure comparison was made between the initial- and long-term used-NiFeCr-LDH. The findings reveal that the material's distinctive structural evolution behavior confers it with exceptional self-adaptability to the OER reaction, which results in a consistent enhancement of activity lasting up to 12 h during long-term I-t test showing a new idea for the design of high performance NiFeCr-LDH. • A series of NiFeCr-LDH-x were designed to study Cr doping' optimal ratio and effect. • NiFeCr-LDH-0.36 has a 0.40% activity loss after 12 h of OER operation and a 0.2% change after 5000 C V cycles. • Cr' threshold effect affects the electrochemical properties and microstructure of catalyst. • The self-adaptation induced by Cr improves the activity and stability of the catalyst. [ABSTRACT FROM AUTHOR]

Downsizing Pt-based catalysts to generate a higher surface-to-volume ratio and maximize atom utilization efficiency has been recognized as an effective strategy to achieve high mass activity. However, the synthesis of homogeneous, ultra-small bimetallic nanoclusters remains a significant challenge due to the difficulties in controlling stoichiometry and surface state control, large miscible gaps between different metals and surface state changes induced by the reaction gas environment. In this paper, bimetallic Pt-based nanoclusters such as PtPd, PtRu, PtCu deposited on carbon black (Vulcan XC72R) were fabricated by the reduction of H 2 plasma.The structure and morphology of those prepared catalysts were revealed by HAADF-STEM, HR-TEM, EDS and XPS. The results indicated the prepared Pt-based nanoclusters displayed high dispersibility and small size owning to the non-equilibrium characteristics of non-thermal plasma (NTPs). The average sizes of PtPd, PtRu and PtCu were 2.06 ± 0.68 nm, 3.66 ± 1.34 nm and 1.98 ± 0.7 nm, respectively. Meanwhile, the synthesized PtPd nanoclusters with the ratio of 3:4 exhibited high catalytic activity in the hydrogen evolution reaction (HER). The Pt 3 Pd 4 /VR-P displayed a low overpotential (19 mV) at 10 mA/cm2 and achieved a high mass activity of 5.4 A/mg for HER in 0.5 M H 2 SO 4 solution, which was 13.8 times higher than those of the commercial Pt/C catalysts. Moreover, the Pt 3 Pd 4 /VR-P demonstrated excellent stability with a negatively shifting about 40 mV after 10,000 cycles at a current density of 10 mA/cm2, which was close to that of JM-Pt/C (32 mV). The results prove NTPs technology is effective for the preparation of bimetallic Pt-based nanoclusters. Non-thermal plasma is an innovative method to prepare Pt-based nanoclusters with high dispersibility and small size. The synthesized Pt 3 Pd 4 nanoclusters with an average size of 2.06 ± 0.68 nm displayed a low overpotential (19 mV) at 10 mA/cm2 and achieved a high mass activity of 5.4 A/mg for HER in 0.5 M H 2 SO 4 solution, which was 13.8 times higher than that of the commercial Pt/C catalysts. [Display omitted] • A plasma fabrication technique for synthesis of Pt-based nanoclusters with high dispersibility and small size was developed. • The average sizes of the prepared PtPd, PtRu and PtCu nanoclusters are 2.06 ± 0.68 nm, 3.66 ± 1.34 nm and 1.98 ± 0.7 nm. • The prepared Pt 3 Pd 4 /VR-P exhibits a low overpotential (19 mV) at 10 mA cm−2 and a high mass activity (5.4 A mg−1) for HER. [ABSTRACT FROM AUTHOR]

Tin dioxide (SnO 2) is widely utilized for the cost-effective electron transport layer (ETL) in perovskite solar cells (PSCs) owing to its excellent optoelectronic properties. However, the surface defect states present in SnO 2 ETL prepared by conventional solution methods seriously hinder the further improvement of device photovoltaic performance. It is urgently essential to develop a facile strategy to effectively minimize the adverse effects of SnO 2 ETL on PSCs. Herein, a phosphorus hetero-phenanthrene flame retardant, DOPO, is introduced as a multifunctional surface modifier to improve the interfacial properties between SnO 2 ETL and perovskite. Through systematic characterization analysis, the P O group in DOPO not only passivates the defective states on the surface of SnO 2 ETL, but also provides chemical chelation sites for the uncoordinated Pb2+ ions in the upper perovskite structure to improve the film crystalline quality. Eventually, the photoelectric conversion efficiency (PCE) of the optimized device is improved from an initial 19.74 %–22.57 %, along with significantly improved device stability. This work provides an important reference for the development of new multifunctional interface modification materials required for SnO 2 -based planar PSCs with excellent properties. [ABSTRACT FROM AUTHOR]

Enhancing the electronic and ionic conductivity of Li 4 Ti 5 O 12 electrode materials, as well as suppressing the interface reaction between Ti4+ on the surface of Li 4 Ti 5 O 12 and the electrolyte, is one of the key factors in preparing high-power and long-life Li 4 Ti 5 O 12 lithium-ion batteries. To tackle these challenges, fluorine ions with strong electronegativity was chosen as dopants to engineer fluorine-doped Li 4 Ti 5 O 12 electrode materials. Fluorine ion doping changes the surface state of Li 4 Ti 5 O 12 , increases the interface compatibility, suppresses the reactivity between Li 4 Ti 5 O 12 and the electrolyte, and forms a uniform SEI film during cycling. Moreover, fluorine ion doping induces the generation of oxygen vacancies and improves the crystallinity of Li 4 Ti 5 O 12 , thereby fostering improved electronic and ionic transport kinetics. The above appealing features enables the prepared fluorine-doped Li 4 Ti 5 O 12 material demonstrates exceptional high-rate performance, delivering specific capacities of 175 mAh·g−1/0.5C, 159 mAh·g−1/10C, and 138 mAh·g−1/50C. In essence, the fluoride ion doping strategy holds profound implications for enhancing electrode interface characteristics, transport kinetics, and the fabrication of high-power lithium-ion batteries. [ABSTRACT FROM AUTHOR]

[Display omitted] Owing to the outstanding properties provided by nontrivial band topology, topological phases of matter are considered as a promising platform towards low-dissipation electronics, efficient spin-charge conversion, and topological quantum computation. Achieving ferroelectricity in topological materials enables the non-volatile control of the quantum states, which could greatly facilitate topological electronic research. However, ferroelectricity is generally incompatible with systems featuring metallicity due to the screening effect of free carriers. In this study, we report the observation of memristive switching based on the ferroelectric surface state of a topological semimetal (TaSe 4) 2 I. We find that the surface state of (TaSe 4) 2 I presents out-of-plane ferroelectric polarization due to surface reconstruction. With the combination of ferroelectric surface and charge-density-wave-gapped bulk states, an electric-switchable barrier height can be achieved in (TaSe 4) 2 I-metal contact. By employing a multi-terminal-grounding design, we manage to construct a prototype ferroelectric memristor based on (TaSe 4) 2 I with on/off ratio up to 103, endurance over 103 cycles, and good retention characteristics. The origin of the ferroelectric surface state is further investigated by first-principles calculations, which reveal an interplay between ferroelectricity and band topology. The emergence of ferroelectricity in (TaSe 4) 2 I not only demonstrates it as a rare but essential case of ferroelectric topological materials, but also opens new routes towards the implementation of topological materials in functional electronic devices. [ABSTRACT FROM AUTHOR]

[Display omitted] The Bloch band theory and Brillouin zone (BZ) that characterize wave-like behaviors in periodic mediums are two cornerstones of contemporary physics, ranging from condensed matter to topological physics. Recent theoretical breakthrough revealed that, under the projective symmetry algebra enforced by artificial gauge fields, the usual two-dimensional (2D) BZ (orientable Brillouin two-torus) can be fundamentally modified to a non-orientable Brillouin Klein bottle with radically distinct manifold topology. However, the physical consequence of artificial gauge fields on the more general three-dimensional (3D) BZ (orientable Brillouin three-torus) was so far missing. Here, we theoretically discovered and experimentally observed that the fundamental domain and topology of the usual 3D BZ can be reduced to a non-orientable Brillouin Klein space or an orientable Brillouin half-turn space in a 3D acoustic crystal with artificial gauge fields. We experimentally identify peculiar 3D momentum-space non-symmorphic screw rotation and glide reflection symmetries in the measured band structures. Moreover, we experimentally demonstrate a novel stacked weak Klein bottle insulator featuring a nonzero Z 2 topological invariant and self-collimated topological surface states at two opposite surfaces related by a nonlocal twist, radically distinct from all previous 3D topological insulators. Our discovery not only fundamentally modifies the fundamental domain and topology of 3D BZ, but also opens the door towards a wealth of previously overlooked momentum-space multidimensional manifold topologies and novel gauge-symmetry-enriched topological physics and robust acoustic wave manipulations beyond the existing paradigms. [ABSTRACT FROM AUTHOR]

Grinding of hardened components always bears the risk of detrimental thermo-mechanical modifications in the surface/sub-surface region. For the non-destructive detection of these damages also known as grinding burns, micromagnetic methods have found increasing interest. Existing studies on the detectability of grinding burn by Barkhausen noise evaluation point out the need for a combination of different characteristic values to distinguish between damage-free surfaces and different pronounced damages. Besides Barkhausen noise, the 3MA-II-method offers three additional measurement techniques that were also investigated in this study. Results show the potential of a combination of Incremental permeability and Harmonic analysis for the detection and distinction of different classes of grinding damages. On the other hand, no clear definition exists to categorize different levels of damages. The classification provided by the observed grey-scale after nital etching is often used, which is rather subjective and cannot be quantitatively described in terms of surface-near properties. Therefore, the present study gives a new attempt to define a parameter that describes quantitatively the existing surface state and its level of damage based on X-ray diffraction analysis. It describes the surface state characterized by the peak width, related to hardness and residual stresses in one single parameter. The investigations show that this approach could be validated for different workpieces and heat treatment conditions, and could allow a quantitative classification of damages thus making non-destructive analysis easier to apply. [ABSTRACT FROM AUTHOR]

We report an in-situ construction strategy of Z-type In 2 O 3 @InP hydrogen evolution reaction (HER) electrocatalyst with well-defined core-shell structure on nickel foam (In 2 O 3 @InP/NF) via sequential hydrothermal, annealing, and phosphating steps. The phosphating time dramatically affects the morphology, crystal phase, elemental composition, and optical properties of In 2 O 3 @InP. The resulting electrode obtained with 2 h of phosphating time has smaller overpotentials and Tafel slope, larger TOF and ECSA, and lower charge transfer resistance compared to In 2 O 3 /NF. The better activity reveals the promoted roles of InP that can provide more active sites, facilitate charge transfer, and accelerate the adsorption of H* species. The photo-assisted electrocatalytic activity for HER is significantly enhanced attributed to the strong light absorption capacity of InP, superior energy level configuration of In 2 O 3 and InP, and excellent transient light response of In 2 O 3 @InP. Furthermore, the electrode has favorable stability and durability, and the morphology and surface chemical state have no essential changes after the photo-assisted HER stability test. The promoting mechanism of photo-assisted HER for the Z-type In 2 O 3 @InP/NF electrode and HER activities in the dark and under AM 1.5 G light illumination. [Display omitted] • The in-situ construction strategy of In 2 O 3 @InP core-shell heterostructure is used. • The InP layer enhances surface chemical states and optical properties of In 2 O 3. • In 2 O 3 @InP has superior photo-assisted activity, stability, and durability for HER. • The promoting mechanism of photo-assisted HER for Z-type In 2 O 3 @InP is determined. [ABSTRACT FROM AUTHOR]

Vortices and bound states offer an effective means of comprehending the electronic properties of superconductors. Recently, surface-dependent vortex core states have been observed in the newly discovered kagome superconductors CsV 3 Sb 5. Although the spatial distribution of the sharp zero energy conductance peak appears similar to Majorana bound states arising from the superconducting Dirac surface states, its origin remains elusive. In this study, we present observations of tunable vortex bound states (VBSs) in two chemically-doped kagome superconductors Cs(V 1− x Tr x) 3 Sb 5 (Tr = Ta or Ti), using low-temperature scanning tunneling microscopy/spectroscopy. The CsV 3 Sb 5 -derived kagome superconductors exhibit full-gap-pairing superconductivity accompanied by the absence of long-range charge orders, in contrast to pristine CsV 3 Sb 5. Zero-energy conductance maps demonstrate a field-driven continuous reorientation transition of the vortex lattice, suggesting multiband superconductivity. The Ta-doped CsV 3 Sb 5 displays the conventional cross-shaped spatial evolution of Caroli-de Gennes-Matricon bound states, while the Ti-doped CsV 3 Sb 5 exhibits a sharp, non-split zero-bias conductance peak (ZBCP) that persists over a long distance across the vortex. The spatial evolution of the non-split ZBCP is robust against surface effects and external magnetic field but is related to the doping concentrations. Our study reveals the tunable VBSs in multiband chemically-doped CsV 3 Sb 5 system and offers fresh insights into previously reported Y-shaped ZBCP in a non-quantum-limit condition at the surface of kagome superconductor. [ABSTRACT FROM AUTHOR]

Cutting and abrasive processes affect the surface layer state of the components treated. This determines their performance in service. An adjustment of the surface layer properties would allow for enhanced performance. This paper introduces the influences of named processes on the surface layer state and their systematics. Models and sensor concepts for surface conditioning are described and combined to soft sensors which are the basis for active control within the processes. A validation study and actual applications of the conditioning concept are shown, allowing for further technological and scientific understanding of surface conditioning and its contribution to material and energy efficiency. [ABSTRACT FROM AUTHOR]

Compared to conventional Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3-δ (BSCF) and La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ (LSCF), BaCo 0.4 Fe 0.4 Zr 0.1 Y 0.1 O 3-δ (BCFZY) with special surface species and structure can exhibit a distinctive compromise between the redox activity and cell stability. The X-ray photoelectron spectroscopy (XPS), temperature-programmed desorption (TPD) and infrared spectrum (IR) results suggest that besides the oxygen species of BSCF and LSCF, the OH-related species can be detected on BCFZY, which can play a promoting role in oxygen catalysis activity. The O2− -conducting solid oxide fuel cell (SOFC) with BCFZY cathode shows the superior power densities at intermediate temperatures (750-650 °C), which are 1.2–1.6 times than those of BSCF cell, and 1.8–2.1 times than those of LSCF cell. Distribution of relaxation times (DRT) analysis on three symmetric cells and three single cells reveal that BCFZY cathode shows superior oxygen adsorption and dissociation, which can be ascribed to the peculiar OH-related species and multiscale structure on the surface. The cell with BCFZY cathode can remain the stable performance during the discharge testing at 650 °C for 240 h, indicating a reliable surface state to promote both oxygen catalysis activity as well as the performance stability for O2− -conducting SOFC. • BCFZY demonstrates considerable activity vs BSCF and LSCF on O2--conducting SOFC. • BCFZY cell achieves high power density (1.99–1.40 W cm−2) at 750-650 °C. • BCFZY cathode exhibits superior oxygen exchange processes on surface. • The special surface state of BCFZY cathode improves O 2 catalysis and stability. [ABSTRACT FROM AUTHOR]

In this paper, CoMn based nanowires were in-situ grown on foam nickel by hydrothermal method combined with calcination treatment, and a monolithic methane oxidation catalyst was obtained. The effects of hydrothermal temperature and calcination temperature on the crystal structure, micro morphology and catalytic performance of the catalysts were systematically studied. The results indicated that when the hydrothermal temperature was 160 °C and the calcination temperature was 350 °C, Mn doped Co 3 O 4 nanowires with uniform morphology can be obtained, accompanied by the appearance of CoMn 2 O 4. The introduction of Mn ions caused lattice distortion of Co 3 O 4 , achieving the regulation of adsorbed oxygen and lattice oxygen. The monolithic MnCoO/NF–H-160 °C catalyst showed the best catalytic activity (T 90 = 414 °C) for lean methane catalytic oxidation, which even surpassed the noble metal based catalyst. Its excellent catalytic activity was due to the fact that the catalyst can expose more active sites, rich active oxygen and good mass transfer characteristics. This study provides a new approach for designing efficient monolithic catalysts and has significant potential for application and development in the field of organic waste gas treatment. [ABSTRACT FROM AUTHOR]

Co-precipitation method was applied to prepare five Cu-containing spinels CuB 2 O 4 with different B-sites (CuCo 2 O 4 , CuAl 2 O 4 , CuMn 2 O 4 , CuLa 2 O 4 , CuCr 2 O 4) and the physicochemical properties of the spinels were characterized comprehensively. The Cu-containing spinels were then washcoated on Cu foams to fabricate monolithic catalysts and the catalytic performance of the catalysts under different reaction conditions was investigated in a methanol steam reforming microreactor. The effects of B-site on the structure-activity relationship and sustained release catalysis were discussed in detail. Results showed that the CuCo 2 O 4 spinel with small particles, excellent reducibility, low acidity, large specific surface area and superior surface chemical state led to the best performance of the monolithic catalyst loaded with CuCo 2 O 4. The B-site resulted in completely different characteristics of spinels, leading to diverse sustained release properties during the catalysis. Owing to the sustained release behavior, the catalytic stability of the Cu-containing spinel was significantly improved compared with the conventional Cu-based catalyst. • Cu-containing spinels with different B-sites were used for methanol steam reforming. • CuCo 2 O 4 spinel exhibited the best performance due to its excellent characteristics. • The effects of B-site on the structure-activity relationship were discussed. • The process of the sustained release catalysis was proposed. [ABSTRACT FROM AUTHOR]

Enhancing computability of cerebral recordings and connections made with human/non-human brain have been on track and are expected to propel in our current era. An effective contribution towards said ends is improving accuracy of attempts at discerning intricate phenomena taking place within human brain. Here and in two different capacities of experiments, we attempt to distinguish cerebral perceptions shaped and affective states surfaced during observation of samples of media incorporating distinct audio–visual and emotional contents, through employing electroencephalograph/EEG recorded sessions of two reputable datasets of DEAP and SEED. Here we introduce AltSpec(E3) the inceptive form of CollectiveNet intelligent computational architectures employing collective and concurrent multi-spec analysis to exploit complex patterns in complex data-structures. This processing technique uses a full array of diversification protocols with multifarious parts enabling surgical levels of optimization while integrating a holistic analysis of patterns. Data-structures designed here contain multi-electrode neuroinformatic and neurocognitive features studying emotion reactions and attentive patterns. These spatially and temporally featured 2D/3D constructs of domain-augmented data are eventually AI-processed and outputs are defragmented forming one definitive judgement. The media-perception tracing is arguably first of its kind, at least when implemented on mentioned datasets. Backed by this multi-directional approach and in subject-independent configurations for perception-tracing on 5-media-class basis, mean accuracies of 81.00% and 68.93% were obtained on DEAP and SEED, respectively. We also managed to classify emotions with accuracies of 61.59% and 66.21% in cross-dataset validation followed by 81.47% and 88.12% in cross-subject validation settings trained on DEAP and SEED, consecutively. [ABSTRACT FROM AUTHOR]

In this work, we have prepared a series of Pd catalysts on a CN x support for the liquid phase decomposition of formic acid. The structured CN x support was obtained through thermal pyrolysis of melamine foam and the pyrolysis conditions were optimized to achieve high surface area. The resulting support contains high amount of nitrogen with a contribution of pyridinic component. Several Pd catalysts were prepared and under optimized conditions, we were able to obtain small (2.7 ± 0.9) nm Pd particles by using the oxidized support in powdery form. The activity of the optimized catalyst was studied under different conditions in the fresh and the used form. The fresh catalyst did not show significant activity. However, we found that the catalyst activated after use. Activation was understood in terms of the variation of surface Pd oxidation states under the effect of formic acid/sodium formate solutions. We found that the best activity is achieved under an optimal proportion of Pd0/PdII surface states according to previous reports. Under the best conditions, the activity of the best catalyst (8.6Pd/CN 0.3) was as high as 9245 h−1, attributable to the small particle size, the Pd0/PdII ratio, the amount of pyridinic nitrogen, and the testing conditions, which included the preadsorption of sodium formate. [Display omitted] • We prepared CN x -supported Pd catalysts for the decomposition of formic acid. • The CN x support was obtained by thermal pyrolysis of melamine foam at 700 °C. • We obtained 2.7nm Pd particles on the oxidized CN 0.3 support under optimized conditions. • The optimized 8.6Pd/CN 0.3 catalyst was not very active but activated upon use. • Activation understood in terms of the variation of surface Pd0/PdII states after use. [ABSTRACT FROM AUTHOR]

Enamel coating has potential application in steel rebar protection due to its high durability, excellent corrosion resistance, and strong coating/concrete interface bond. The newly developed low temperature enamel (LTE) coating has a substantially lower sintering temperature than that of traditional enamel coatings, whereas its adhesion mechanism to the substrate is expected to vary dramatically. In this study, abrasives of various particle sizes were used to blast steel substrates to create various surface states, to investigate the influence of substrate surface roughening on the interfacial properties of LTE coating. The surface roughness of substrates was quantitatively characterized by a 3D optical profiler. The adhesion, impact resistance, and abrasion resistance of LTE coating under different substrate surface states were investigated by pull-off, falling weight impact, and Taber abrasion test, respectively. The results showed that with increasing substrate surface roughness, the adhesion strength and impact resistance of the LTE coating were greatly improved. Within the investigated range, the substrate surface roughness had negligible influence on abrasion resistance. Overall, appropriate substrate surface roughening can provide the LTE coating with sufficient interface adhesion, impact resistance, and abrasion resistance. [ABSTRACT FROM AUTHOR]

In this study, a methodological approach is pursued to gain an elaborated understanding concerning the Devanathan-Stachurski technique. Different experimental test parameters such as the polarization potential at the exit side, the applied charging current density, the electrolyte, the oxygen content, the sample roughness and the electrolyte composition, are modified to evaluate their influence. It is found that the surface roughness and possible contaminations from of the electrolyte are of high importance for realizing a stable entrance surface state. Furthermore, the partial transient procedure can be used for determining a diffusion coefficient which approaches the lattice diffusion coefficient. • ParaMetric evaluation of the electrochemical hydrogen permeation technique. • Role of sample roughness is key for a stable hydrogen entry flux. • Impact of the electrolyte purity revealed leading mismatch with ideal Fick's law. • Consecutive charging cannot be done when surface sides are not constant. • Methodology developed yielding a perfect with between experiment and theory. [ABSTRACT FROM AUTHOR]

Bismuth vanadate (BiVO 4) has attracted wide attention as photoanode in water-splitting photoelectrochemical (PEC) devices. However, its catalytic performance is greatly limited by the serious charge recombination on the surface states. Herein, borate modified BiVO 4 plus additional CoPi cocatalyst (B-BVO/CoPi) is developed as photoanode for PEC cell via a simple soaking and electrodeposition process. Based on the electrochemistry tests and material characteristics, the borate groups [B(OH) 4 ] – is able to effectively prevent the charge recombination, while the outer CoPi cocatalyst enhance the activity toward oxygen evolution reaction. Therefore, the designed B-BVO/CoPi photoanode could obtain a high current density of 2.67 mA cm−2 at 1.23 V RHE with an onset potential of 0.29 V RHE , much higher than pristine BiVO 4 (0.78 mA cm−2, 0.52 V RHE). This work may provide a new insight for constructing multifunctional modified photoanodes for efficient solar conversion. [Display omitted] • A facile immersion method was employed to enhance the charge separation efficiency on BiVO 4 photoanode surface. • Synergistic effect of borate groups [(B(OH)-)] and CoPi cocatalyst can facilitate charge transfer in the interface. • The integrated photoanodes well improve photoelectrochemical performance compared to pristine BiVO 4 photoanode. [ABSTRACT FROM AUTHOR]

[Display omitted] Catalytic descriptors of electrocatalysts such as d -band center are the important indicators that connect the physiochemical interaction and catalytic performance and have been used for rational design of the catalysts and performance optimizations. However, these descriptors developed in traditional electrocatalysts are invalid in recent emerged topological catalysis. Here, we identify topological surface state (TSS) density at the Fermi level can serve as the universal catalytic descriptor in the family of metal diborides, the materials hosting fantasying topological nodal-net states. The catalytic activity for hydrogen evolution reaction (HER) is linearly correlated with the projected TSSs on corresponding surfaces, which are independent on the material types. The findings are further proven by the weakened HER performance under topological phase transition where the TSS density at Fermi level is reduced, and the revival of d -band center once all the TSSs are removed. Our work will open a new route for developing high-performance catalysts from the quantum topological point of view. [ABSTRACT FROM AUTHOR]

Tungstate-based scheelite structures have attracted much attention for the photocatalytic, adsorption and luminescence. To improve their performance, several ways have been considered, such as morphology control, thermal treatment and nanostructuring materials. In this work, three uniform and homogeneous morphologies, such as spindles, spheres and flowers, of self-assembled three-dimensional Na 0.5 Ce 0.5 WO 4 were used as photocatalysts for methylene blue dye photodegradation under solar irradiation. Depending on morphology, they required different temperatures to reach crystallization. Thermal treatments at 500 °C and 800 °C resulted in changes in crystallite size, porosity, surface state, but also in bandgap and emission properties. Thus, the crystallite sizes are about 50 nm for samples (spindles and flowers) treated at 500°Cand 87–167 nm for those treated at 800 °C. Their respective bandgap values measured by diffuse reflectance were 2.85 eV beyond 3.15 eV. The samples treated at 500 °C showed a lower emission and a longer charge carrier lifetime. A strong trend to adsorption was revealed, especially at low pH value and for the samples treated at 500 °C, reaching 100% at a pH value of 2.5. With decreasing pH, the photocatalysis activity increases (up to 50%), being also more efficient with catalysts treated at low temperature. It follows that the degradation efficiency of spindles treated at 500 °C is clearly higher compared to other morphologies treated at different temperature, and suitable for solar photocatalysis. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pd/UiO-66(Ce) catalysts were prepared for the degradation of single and mixed VOCs. • The competitive adsorption between mixed VOCs was systematically studied. • Revealed the degradation mechanism of VOCs on Pd/UiO-66(Ce)-Na catalyst. Herein, Pd/UiO-66(Ce) catalysts were successfully synthesized by N 2 H 4 , H 2, and NaBH 4 reduction methods with UiO-66(Ce) as support. The best catalyst was selected via utilizing o -xylene as the probe molecule, and its degradation performance of mixed VOCs was further investigated. It was found that the reduction methods greatly influenced the size of Pd nanoparticles, the state of surface Pd, and the support structure in the catalysts, which in turn affected their catalytic performance. Among them, Pd/UiO-66(Ce)-Na exhibited the best o -xylene degradation activity (T 90 = 192 °C) due to its smaller average Pd particle size (Pd Average = 2.93 nm) and higher surface Pd0 content (Pd0/Pd total = 0.79). The performance and interaction of Pd/UiO-66(Ce)-Na catalyst for degradation of mixed VOCs (o -xylene and toluene/benzene) were investigated by DFT adsorption energy calculation, in situ DRIFTS and GC–MS. Results suggested that the single adsorption energy of o -xylene was −1.20 eV, while in the system with toluene/benzene, the adsorption energy decreased to −0.78 and −0.6 eV, respectively. This showed the competitive adsorption effect between benzene and o -xylene was stronger than that between benzene and o -xylene. Finally, combined with in situ DRIFTS and GC–MS, the degradation path of mixed components was analyzed and studied systematically, and the mechanism of intermolecular interaction of benzene in the degradation process of mixed components was further revealed. [ABSTRACT FROM AUTHOR]

Breaking the Coulomb force between photogenerated carriers is the key to promoting effective carrier separation. In this study, a phosphorus-induced strategy of step-by-step corrosion of substituted oxygen atoms was employed to construct a stable P(δ-)–Co(δ+)-O(δ-) surface bonding state using CoAl-LDH as a template. It is shown that the step-by-step corrosion construction of this surface bonding state can serve as a fast migration channel for photogenerated electrons, effectively promoting the photogenerated electrons to break free from the Coulomb force. In situ irradiation XPS demonstrates the electron migration pathway, proving that the P(δ-)–Co(δ+)-O(δ-) surface bonding state assumes the role of efficiently migrating electrons. Density Functional Theory (DFT) provides further insight into the electronic states and contributions of the catalysts and provides a theoretical basis for the study of the mechanism. This work opens new horizons for the development of phosphorus-induced progressive corrosion strategies to introduce surface-active bonding states, and for advanced materials design and optimization for sustainable energy applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Lower pore volume, and fewer alkaline sites limit SO 2 oxidation. • V 2 O 5 -WS 2 /TiO 2 catalysts boost SO 3 inhibition compared to V/Ti and V-W/Ti catalysts. • Low-valence sulfur plays a critical role in the inhibition of SO 3 production. • S2− reduces V5+ to a lower valence, thereby preventing SO 3 formation at the source. • W-S bond reduces HSO 4 − intermediate formation, thereby decreasing SO 3 generation. The by-product SO 3 , generated by the conventional catalyst V 2 O 5 -WO 3 /TiO 2 employed in selective catalytic reduction (SCR) systems, has garnered attention in pollution control efforts. Studies on existing control have predominantly concentrated on the tail gas section, with insufficient understanding of in-situ suppression theories and methods at the source of SO 3 generation. We propose for the first time the introduction of low-valence reduced sulfur to synthesize a novel SCR catalyst, V 2 O 5 -WS 2 /TiO 2 , which elucidates the remarkable effect and in-situ mechanism of action in inhibiting SO 3 formation at its source. Compared to conventional catalysts, the new catalysts showed enhanced SO 3 inhibition, particularly at 350 °C, where SO 3 production was 64.1 % and 33.9 % lower than that with VTi and VW/Ti catalysts, respectively. This was due to their reduced surface area, smaller pore volume, and fewer alkaline sites, which hindered SO 2 adsorption and oxidation. The results revealed that S2− on the catalyst surface reacts with V5+, reducing it to V4+ and V3+. This reaction hinders the interaction between V5+-OH and adsorbed SO 2 , thereby reducing the formation of VOSO 4 intermediates. Furthermore, the W S bond in WS 2 impedes the formation of intermediate HSO 4 −, and the reduction of these intermediates ultimately leads to a decrease in SO 3 generation. Additionally, the incompletely depleted S2− reacts with the final SO 3 produced, forming SO 2 and SO 4 2−, which further decreases the SO 3 generation rate and supports the maintenance of a reduced state on the catalyst surface. It is evident that low-valence reduced sulfur plays a crucial role in inhibiting SO 3 generation. [ABSTRACT FROM AUTHOR]

Topological materials are widely esteemed for their surface metallic states and remarkable carrier mobility, making them effective catalysts for heterogeneous processes. This study showcases the outstanding properties of Fe 2 VAl, an experimentally prepared compound that enjoys a Cu 2 MnAl-type Heusler structure. It specifically highlights the presence of robust obstructed surface states on the (001) surface and the outstanding catalytic effectiveness of the compound in electrochemical hydrogen evolution processes (HER). The band structure calculation in this work shows that it is an obstructed atomic semimetal with a pseudo-gap of −0.088 eV (nearly −0.1 eV). These findings align with the previous optical conductivity measurements conducted at low temperatures, which also showed a similar pseudo-gap. This work suggests that the easily prepared Fe 2 VAl compound may be an excellent topological quantum material for topological catalysis. [ABSTRACT FROM AUTHOR]

[Display omitted] • The type-II and type-I nanostructures band structures of Te@CNT and Te@BNNT are obtained, respectively. • The influence of strain on the electronic properties and transport properties of Te nanowires and Te@NTs are clarified. • A great enhancement of carriers mobility in Te@NTs is predicted. A comparative investigation of electronic and transport properties of Te single atomic chain and Te single atomic chain encapsulated in carbon and boron nitride nanotubes (Te@CNT and Te@BNNT) based on first principle calculations. It is found Te@CNT and Te@BNNT show, respectively, type-II and type-I nanostructures with direct bandgap, and the band alignment relates to the diameter of NTs, whereas Te single atomic chain shows the transition between indirect and direct with compressive strain. Moreover, acoustic deformation potential (ADP) and ionized impurity (IMP) scattering rate play primarily responsible for the reduction of transport properties of Te single atomic chain and Te@NTs. The existence of NT can provide favorable surroundings to passivate dangling bonds and weak surface states for achieving high transport properties, and Te@CNT has the highest mobility due to the optimization of electronic and transport properties by CNT. Our results provide a guideline for designing high performance of 1D nanostructure for desirable applications. [ABSTRACT FROM AUTHOR]

The scaling relationship and improvement of the catalytic performance of Fe, Mn, Cu, Ti, and Cr containing heteronuclear dual-atom catalysts supported by B,N-doped biphenylene (BPN) is presented. Figure 1: To simplify, the protons and electrons (H + + e −) in the primary reactions are removed. Included are the probable intermediates in CO 2 RR on TM-BPN via the four basic processes of CO 2 chemisorption, CO 2 activation, chemical synthesis, and product desorption respectively. The gas is represented by g, and the liquid by l. [Display omitted] • The CO2 RR activity of 3d transition metal (TM) dual atoms decorated BPN were investigated. • The catalysts supported by B,N-doped biphenylene (BPN) at different doping sites. • The scaling relationship and improvement of the catalytic performance of Fe, Mn, Cu, Ti, and Cr are presented. The electrochemical carbon dioxide reduction reaction (CO 2 RR) provides an attractive approach to converting renewable electricity into fuels and feedstocks in the form of chemical bonds. The CO 2 RR activity of 3d transition metal (TM) atoms decorated BPN with substitutional doping is investigated. The structural and chemical factors supporting the reduction of CO 2 to CO and increasing the reaction activity are also discussed. The calculated results indicate that TM atoms on BPN exhibit adequate electrochemical stability. The scaling relationship and improvement of the catalytic performance of Fe, Mn, Cu, Ti, and Cr-containing heteronuclear dual-atom catalysts supported by B,Ndoped biphenylene (BPN) are also presented. Among these configurations, N-CuTi having a G *COOH -*CO of −2.832 eV, is found to demonstrate the most effective CO 2 RR electrocatalysis performance.Three high-activity heteronuclear dual-atom catalysts surpass the lowest theoretical overpotential. [ABSTRACT FROM AUTHOR]

In this paper, a CoGa-Layered Double Hydroxides Modified Tin-Doped Hematite Photoanode was prepared and utilized for highly efficient solar water splitting. [Display omitted] • CoGa-LDH cocatalyst grown in situ on tin doped hematite photoanode was prepared by a simple hydrothermal method. • The CoGa-LDH/Sn-Fe 2 O 3 exhibits a significantly improved photocurrent density compared to that of α-Fe 2 O 3. • The CoGa-LDH/Sn-Fe 2 O 3 has excellent stability and the lower onset potential. • The reasons and mechanisms for efficient water splitting in CoGa-LDH/Sn-Fe 2 O 3 have been studied and clearly revealed. Hematite suffers from low carrier concentration, limited hole diffusion distance, intricate surface states, and sluggish kinetic process of water oxidation, resulting in its inadequate performance for photoelectrocatalytic (PEC) water oxidation. This paper presents a method that combines tin doping and in situ growth of cobalt-gallium layered hydroxide co-catalysts to enhance the performance of the α-Fe 2 O 3 photoanodic oxygen evolution reaction (OER). The optimal CoGa-LDH/Sn-Fe 2 O 3 exhibits a significantly improved photocurrent density of 1.08 mA/cm2 at 1.23 V vs. RHE, representing an 86 % enhancement compared to that of Sn-Fe 2 O 3 , and it demonstrates remarkable stability. Additionally, the cathodic displacement of CoGa-LDH/Sn-Fe 2 O 3 is observed to be 80 mV relative to the onset potential of Sn-Fe 2 O 3. Systematic studies have demonstrated that tin doping significantly enhances the density of carriers in hematite and reduces the charge migration impedance of hematite, while the utilization of CoGa-LDH co-catalysts mitigates the complexation of photogenerated electron-hole pairs and reduces the transport resistance of photogenerated holes at the photoanode-electrolyte interface, consequently promoting the mobility of holes. [ABSTRACT FROM AUTHOR]

[Display omitted] • The treated NO γ-Al 2 O 3 exhibits an XPS N1s peak sensitive to NO gas. • γ-Al 2 O 3 in NO + H 2 environment shows the same peak of XPS N1s. • Coulomb and magnetic interactions hold distant d -NO states. • The simulated O- KLL region for d -NO is consistent with the experiment. The modification of γ-Al 2 O 3 after NO treatment and during the NO + H 2 reaction was studied using X-ray photoelectron spectroscopy (XPS) and density functional theory. The XPS N1s spectra contain features with binding energies BE = 399.0 and 403.0 eV; the first is preserved, and the second disappears when NO is removed from the gas phase. The features were identified from experimental and modeled O- KLL regions of possible modification products − NAl n oxynitrides (n = 3; 4) of the γ-Al 2 O 3 (110) surface and adsorbed states. Calculations show that NAl n adsorbs NO, forming normal states with a distance to the surface d = 1.32–1.70 Å and distant (d -NO) states (d = 1.91–2.06 Å) in which the spin-polarized NO molecule is retained due to magnetic NAl n and Coulomb interaction. An increase in the similarity of the O- KLL spectra in the sequence of NO/γ-Al 2 O 3 (110), NO/NAl n and d -NO/NAl n at an adsorption heat of ∼ 0.53, 1.33 and 1.26 eV, respectively, suggests that the modification includes the formation of NO/NAl 4 corresponding to BE = 399.0 eV and d -NO/NAl 4 , which corresponds to BE = 403.0 eV and, being chemically unbound, is able to leave the surface in the absence of NO in the reaction medium. [ABSTRACT FROM AUTHOR]

In this work, for the first time, a density functional theory (DFT) based comprehensive theoretical study is performed on the surface electronic properties of Bi 2 Se 3 nanosheet in the presence of a surface capping layer as well as mechanical strain. The study systematically introduces a biaxial compressive and tensile strain up to 5 % in natural, Sb 2 Se 3 surface capped, and SbBiSe 3 surface capped Bi 2 Se 3 , and the subsequent effects on the electronic properties are assessed from the surface energy band (E-k) structure, the density of states (DOS), band edge energy and bandgap variations, surface conducting state localization, and Fermi surface spin-textures. The result demonstrates that the Sb 2 Se 3 and SbBiSe 3 surface capping layer delocalizes the surface Bloch states leading to inter-surface surface state hybridization through bulk and subsequent Dirac point annihilation with surface bandgap opening, and these effects is more prominent for Sb 2 Se 3 surface capping with a bandgap opening of ∼9 meV. The application of biaxial compressive strain (tensile stress) can further localizes the surface Bloch states and thereby mitigate the surface bandgap opening in surface capped Bi 2 Se 3. In contrast, the application of biaxial tensile strain (compressive stress) enhances the surface Bloch state delocalization leading to larger surface bandgap opening in surface capped Bi 2 Se 3 and even introduces surface bandgap in natural Bi 2 Se 3. The interplay of surface capping and strain also exhibits distinct influence on the spin-momentum locking, where the spin-chirality of the Fermi surface can be destroyed, restored, and even reversed through application of suitable biaxial strain in surface capped Bi 2 Se 3. In essence, this work presents an extensive theoretical and design-level insight into the surface capping and biaxial strain co-engineering in Bi 2 Se 3 , which can potentially facilitate different topological transport for modern optoelectronics, spintronics, valleytronics, bulk photovoltaics applications of engineered nanostructured topological materials in the future. [ABSTRACT FROM AUTHOR]

The combination of non trivial band topology and superconductivity, resulting in topological superconductivity, igniting a fervent pursuit in the realm of quantum materials. Through density functional theory and maximally localized Wannier functions, we delve into the electronic and topological properties of transition metal carbides Λ C (with Λ = Sc, Ti, V). Phonon dispersions guarantee the structural stability of these superconductors. Witness the presence of band inversion within the Brillouin Zone of TiC and VC, contrasting the absence of such band inversion in ScC. In addition, the nonzero Z 2 topological invariant as well as the occurrence of Dirac cone in the surface spectrum of TiC and VC, unveil their topologically nontrivial character. These transition metal carbides emerge as promising candidates for probing the depths of topological superconductivity and unraveling the associated Majorana bound states. [ABSTRACT FROM AUTHOR]

The quest for new luminescent materials, particularly carbon based, is ongoing. Herein, we present results on the synthesis of water-soluble carbon dots via a hydrothermal process using L-ascorbic acid, sodium carbonate, and urea as chemical precursors. The X-ray diffraction patterns suggest that the samples possess sharp maxima corresponding to (002) reflections and sp 3 disorder. The crystallite size was evaluated using the Scherrer formula, a modified Scherrer formula that considers strain using the Williamson–Hall plot, and a Zeta sizer. The diameter is approximately 65 nm. The zeta potential, or surface charge, in all samples shows negative values ranging from −30 to −60 mV, indicating the suitability of the nanoparticles for biological applications. Fourier transform infrared spectroscopy reveals three prominent signatures in our samples at 3300, 1640, and 1390 cm−1, corresponding to O-H, C=O, and C-H vibrations, respectively. The prominent signal in UV-visible absorption spectroscopy is observed in the UV region, with a minor contribution in the visible region, indicating a combined role of the graphitic core and surface states. Photoluminescence emission was obtained in the blue region, and all samples could be excited with near-UV light (around 365 nm). We explored the potential of using blue-emitting nanomaterials for solid-state lighting applications and obtained a color purity of 85% for samples prepared with L-ascorbic acid and urea, suggesting their suitability for lighting application. [Display omitted] • Carbon dots prepared from L-ascorbic acid, sodium carbonate and urea with a crystallite size of 65 nm. • Prominent absorption in the near-UV wavelength region. • Photoluminescence emission in blue-region due to surface defects. • Carbon dots of L-ascorbic acid shows color purity of 85% when compared with blue color. [ABSTRACT FROM AUTHOR]

Thermal modulators based on phase change materials have gained attention due to their ability to self-adaptively tune the heat flux. However, achieving a large positive modulation ratio with increasing temperature remains challenge. In this work, we present a near-field thermal modulator with a large modulation ratio and heat transfer coefficient. The thermal modulator consists of two identical VO 2 metasurfaces placed on planar Au substrates. The thermal modulator can achieve three stages, corresponding to three different combinations of phase states of VO 2. An extremely large heat transfer coefficient with value exceeds 20000 W/m2 K is achieved at a room temperature of 300 K, and the largest modulation ratio is about 12. The underlying mechanism involved in the modulator is the construction of cavity surface plasmon polaritons for the metallic state and the suppression of surface phonon polaritons for the dielectric state. Meanwhile, we numerically demonstrate the excellent modulation performance of the proposed modulator as a contact filling in the spacecraft applications. This work can accelerate the utilization of near-field thermal modulators in thermal management and thermal circuit applications. • Three-stage modulation of near-field radiative heat transfer is achieved by one PCM. • Achieve an extremely large heat transfer coefficient with value exceeds 20000 W/m2 K. • An excellent modulation property is demonstrated with ratio excess 12. • Underlying mechanism involves constructing the cavity SPPs and suppressing SPhPs. • Excellent modulation performance is illustrated for the spacecraft application. [ABSTRACT FROM AUTHOR]

The present study proposes various thermal circuit models (TCMs) to predict interfacial thermal resistances (ITRs) between water and a nanostructure surface. The effects of water models, nanopillar widths on nanostructure surfaces, and composite surfaces on the relationship between ITRs calculated by non-equilibrium molecular dynamics simulations and ITRs predicted by TCMs are investigated in water-copper and water-graphene-copper systems. The results reveal that the ITRs predicted by some TCMs are slightly affected by water pressure, while MD-calculated ITRs of the nanostructure surfaces in the Wenzel states agree with most of the predicted ITRs. Additionally, it is demonstrated that water molecules in the groove of a nanostructure surface play a crucial role in TCMs in the Cassie-Baxter states. Considering the effective contact region of water molecules in the groove in the Cassie-Baxter states, the use of TCMs can effectively reduce the prediction error of ITRs. [ABSTRACT FROM AUTHOR]

Topological insulator and ferromagnet interface conditions affecting charge-spin conversion efficiency extracted by ST-FMR. [Display omitted] • 1-nm-Se-inserted structure preserves the topological surface state, indicating improved spin properties. • Band hybridization between the FM and TI layers exhibits significant changes depending on the thickness of Se. • ST-FMR shows an enhancement in the SHA for the 1-nm-Se-inserted structure, highlighting the proximity effect in TI. Strong spin–orbit coupling and highly spin-polarized surface states in topological insulators (TIs) are key parameters that explain their extremely high charge-to-spin conversion (CSC) efficiency at interfaces with ferromagnetic materials (FMs). This study focused on the influence of the insertion layer on the proximity effect occurring in a Co 4 Fe 4 B 2 /Bi 2 Se 3 interface. Various insertion layers, including Au, MgO, and Se, were introduced to modulate the proximity effect from TI to FM and vice versa. X-ray photoelectron spectroscopy and transmission electron microscopy revealed that the Se insertion layer effectively suppresses the formation of an additional Bi layer, reducing intermixing against Co 4 Fe 4 B 2. Electrical transport properties such as R XX and R XY under a vertical magnetic field show that the Se-inserted structure features the lowest anomalous Hall angle and exhibits a pristine topological surface state, indicating its potential for improving CSC efficiency. The Se-inserted structure exhibits the highest spin Hall angle among various heterostructures, according to results obtained from spin-torque ferromagnetic resonance. These findings highlight the importance of selecting an insertion layer and controlling the interface to optimize the spin-transport properties of TI-based spintronic devices and provide insights into the design of future spin devices. [ABSTRACT FROM AUTHOR]

• Low Pt-loading catalyst layers (CL) of PEMFC were prepared and tested. • Hysteresis in polarization plots is due to water/thermal management and Pt-oxides. • Increased Pt-loading induces heterogeneous transport across CL thickness. • Saturation in CL pores changes the accessibility of Pt to protons. • Potential-dependant Pt surface state is impacted by ionomer adsorption/desorption. In the past decades, the proton exchange membrane fuel cell (PEMFC) components, cell/stack designs and system architecture have been significantly improved. However, despite great initial performance, PEMFC systems still suffer technological limitations, such as their initial cost, partly due to the use of expensive Pt-based electrocatalyst, which prevents widespread industrial deployment. Lowering the cathode catalyst loading while keeping high (and durable) catalytic activity has been intensively studied. In this work, low-loaded catalyst layers (20 and 100 µg Pt cm geo −2) are tested in PEMFC differential single-cell (DC) under high reactant stoichiometry to characterize their intrinsic electrochemical properties under various ideal and well-controlled operating conditions of cell temperature (T) and relative humidity (RH). Particularly, the change of the membrane hydration state, via the ohmic resistance measurement, and the Pt-oxides surface coverage are investigated to gather information on the physico-chemical and electrochemical mechanisms involved in the cathode active layer, and the typical performance hysteresis observed during dynamic operation such as polarization curves. These specific electrochemical measurements further enable to build a dataset, that can be used to improve PEMFC models taking into account the complex ORR mechanism, and the role of the Pt oxides in catalyst layer transient operation and degradation. [ABSTRACT FROM AUTHOR]

The preparation and modulation of bare nano-diamonds (NDs) are of great significant for further investigation into their intrinsic structures, exploring more underlying properties, unlocking latent performances and exploiting more extensive applications. In this study, bare NDs have been successfully synthesized and modulated through 343 nm femtosecond laser ablation in liquids (LAL). When laser scanning point interval (LSPI) was reduced from 4 μm to 0.5 μm, the average size of NDs decreased from 4.1 nm to 3 nm. While it remained around 3.2 nm for NDs obtained at different energies. Notable, sp3-C within NDs accounted for above 71 % at laser energy of diamond damage threshold (118 mW), and then transformed into sp2-C as laser energy increased. NDs prepared in water and ethanol differed in terms of their size distribution, intrinsic structure, and surface state. NDs@ethanol sized 3.8 nm exhibited higher sp3/sp2 ratio and more complex surface states than NDs@water sized 3.3 nm. These findings not only can provide valuable guidance for precise regulation of NDs preparation, but also can offer diverse structural NDs for exploring their potential applications. [Display omitted] [ABSTRACT FROM AUTHOR]

• We prepared three structurally different multi-peak emitting carbon dots using phenylenediamine isomers as precursors. • The fluorescence of all three carbon dots changes depending on the environment. • The multi-peak emission carbon dots have different fluorescence centers resulting from their different structures. Revealing the relationship between structure and optical properties of multi-peak emissive carbon dots (CDs) is important. Three types of multi-peak emission CDs were synthesized by one-step hydrothermal method with phenylenediamine (PD) isomers (o/m/p) and maleic anhydride serving as precursors. During the synthesis process, three PDs exhibited different microstructural and chemical states, resulting in various fluorescence emission centers. The multi-peak emission behavior of o-CDs and m-CDs is composed of molecular fluorophores and carbon core states, while that of p-CDs consists of surface states and carbon core states. These different fluorescence centers lead to diverse fluorescence behaviors of the CDs in different solvents and environments. This work inspires the clarification of the relationship between the structural and optical properties of multi-peak emissive CDs. [ABSTRACT FROM AUTHOR]

[Display omitted] • A rich-scandium dispenser cathode's measured and calculated work function consistently fits well. • The work function of Ba x -O y adsorption on Sc is negatively correlated with the dipole moment. • Polarization and charge transfer of the adsorbed atoms affect the dipole moment. One of the important issues with the scandate cathode is the mechanism by which Sc works on the cathode surface. A surface Sc-rich dispenser cathode was prepared via the vacuum evaporation method to clarify the role of Sc in the cathode performance. The XPS results indicate that the surface chemical state of Sc on the surface after activation is consists of Sc0 and ScƐ+ (0<Ɛ<3). Furthermore, the adsorption energy, the work function, charge density difference, polarization effect and dipole moment of the Ba x -O y adsorbed on the Sc surface were calculated by means of first-principles calculations. The results show that the work function of the Ba x -O y dipole adsorbed on the Sc is 1.9–2.8 eV with the average value of 2.262 eV, which is consistent with the experimentally measured result. The work function of Ba x -O y adsorbed Sc (002) gets to the lowest at a coverage of 25 %O-25 %Ba. The change of dipole moment due to polarization and charge transfer in the adsorbed layer could affect the work function. [ABSTRACT FROM AUTHOR]

• A Cu-MOF material was synthesized via solvothermal method. • The structural analysis confirms the formation of Cu-MOF and the crystallite size is 22.3 nm. • Pentagonal shapes and a novel flower-like image of Cu-MOF formations was illustrated from surface morphology. • The advantageous surface area of 65.152 m2/g was observed in Cu-MOF. • The synthesized material delivered a maximum specific capacitance of 383.3 Fg-1. Today's nanomaterial scientific phases have been evolving through the most considerable novel MOF nano-characters. This study has described that the Cu (Copper) Nano-Metals based Metal-Organic Framework was synthesized by an affordable solvothermal method. With the facilitates of characterization methods, their factual physiochemical properties including Cu-MOF's crystalline characters, vibrational, surface morphology, surface chemical states, and obtained surface area have been examined. The X-ray diffraction–structural examination described the evident formation of metal oxide-coordinated MOF crystalline material. Before calcination, the MOF nanomaterial possessed an actual crystalline character of Cu-MOF with 22.3 nm of crystallite size then it became recrystallized after calcination. The co-contributions of Oxygen-linked organic molecular vibrational signatures upon Cu-O were analyzed through the Fourier Transform Infra-Red spectroscopy. Surface morphological magnifications exhibit plenty of pentagonal-shaped Cu-MOF nanomaterial with uniform distribution. Such a case also exhibits a flower-shaped Cu-MOF between pentagonal shapes with considerable surface porosity. X-ray photoelectron spectroscopy (XPS) has exhibited that the presence of oxygenated molecules contained copper oxide B.E states of synthesized Cu-MOF material. The UV–visible spectroscopy analysis has taken and the estimated bandgap of the Cu-MOF material is 2.3 eV. The thermal stability of the material has been analyzed through Thermo-Gravimetric analysis. To determine the internal structure of the Cu-MOF, an HR-TEM investigation was carried out. BET analysis exhibited 65.152 m2/g of active surface area. Due to the novel particle morphology with beneficial surface characteristics, the Cu-MOF possessed an efficient charge storage capacity of 383.3 Fg-1 due to its novel property. [ABSTRACT FROM AUTHOR]

Recycled aggregate derived from decoration waste, typically consisting of various compositions, makes the workability of mixtures difficult to predict. This study investigated a widely applicable indicator, the void ratio of saturated surface dry state, to establish an association between the properties of mixed recycled aggregate and workability. The packing properties and morphological parameters (including angularity, aspect ratio, circularity and roundness) of the aggregate were measured. The workability of mixture was evaluated through tests of flowability, yield stress and plastic viscosity. Results showed that the void ratio of saturated surface dry state had a strong correlation with the workability of fresh mixtures. This indicator reflected the impact of morphology, gradation and water absorption of the mixed recycled aggregate on packing properties. Based on the indicator, mixture with an excess paste thickness of 10–27 μm exhibited an optimal workability for the application in cementitious backfill materials. The findings of this research can provide a practical indicator to predict the workability of cement-based material incorporated mixed recycled aggregate. • An indicator ε VS that reflected properties of mixed recycled aggregate is established. • High correlation is found between ε VS and workability of cementitious backfill materials. • The threshold of the t p calculated from ε VS is proposed between 10 and 27 μm. • The feasibility of using mixed recycled aggregate from decoration waste is confirmed. [ABSTRACT FROM AUTHOR]

We predict that the appearance of zero-energy Yu-Shiba-Rusinov(YSR) bound states in two different setups, metal-spin flipper-metal-s-wave superconductor ( N 1 − s f − N 2 − S) and superconductor-metal-spin flipper-metal-superconductor (S − N 1 − s f − N 2 − S) junctions, can cause a multi-fold enhancement of surface odd-frequency superconducting pairing. On the other hand, in the absence of these bound states, even-frequency pairing dominates surface odd-frequency pairing. Specifically, in the S − N 1 − s f − N 2 − S Josephson junction, the emergence of zero energy YSR bound states leads to a 0 − π junction transition and surface odd-frequency pairing dominance. Notably, odd-frequency pairing vanishes in the absence of the YSR-bound states. Interestingly, the equal spin–triplet pairing is the dominant component in odd-frequency superconductivity in both setups, which could have important implications for superconducting spintronics. Overall, our findings may help to detect the presence of YSR-bound states through the observation of surface odd-frequency pairing and contribute to a better understanding of their relationship. • We predict that the appearance of zero energy Yu-Shiba-Rusinov (YSR) bound states in two different setups, N 1 − s f − N 2 − S and S − N 1 − s f − N 2 − S junctions, can cause a multi-fold enhancement of surface odd-frequency superconducting pairing. • In the S − N 1 − s f − N 2 − S Josephson junction, the emergence of zero energy YSR bound states leads to a 0 − π junction transition and surface odd-frequency pairing dominance. • Odd-frequency pairing vanishes in the absence of the YSR-bound states in a S − N 1 − s f − N 2 − S junction. • Equal spin–triplet pairing is the dominant component in odd-frequency superconductivity in both setups, which could have important implications for superconducting spintronics. • Our findings may help to detect the presence of YSR-bound states through the observation of surface odd-frequency pairing. [ABSTRACT FROM AUTHOR]

Ti6Al4V alloy has been widely applied in aerospace and biomedical fields due to its excellent thermodynamic performance and biocompatibility, but its wear resistance remains to be improved. This study employed the picosecond pulsed laser-assisted grinding (LAG) to fabricate sinusoidal micro-structured surfaces on Ti6Al4V alloy, and investigated the corresponding tribological behavior and wear mechanism. The results revealed that the micro-structured surfaces exhibited a lower and more stable frictional coefficient, and had advantages on wear resistance. Besides, the best wear resistance could be obtained when the micro-structured width was 100 μm. Moreover, the wear width and depth of the micro-structures are positively related to the stress influencing area. [Display omitted] • The LAG can improve the surface state of the micro-textures, showing lower and more stable friction coefficients. • The primary wear mechanism of the micro-textured surface was abrasive wear and adhesive wear. • The wear width and depth of the micro-textures are positively related with the stress affected area. [ABSTRACT FROM AUTHOR]

To reveal the influence of ultrasonic impact treatment (UIT) parameters on surface state and the influence of surface state on high-temperature tension-tension fatigue behavior, UIT tests were conducted and 400 ℃ high-temperature fatigue tests were performed on UIT specimens with different surface states. The relationship between surface state and process parameters was analyzed, and the fatigue failure mechanism of UIT specimens was revealed. The finite element method was used to explore the influence of different residual stress distributions on the distribution of stress intensity factors at the crack front and the evolution of crack shape. The results show that the surface roughness changes between 0.43 μm and 0.72 μm with the variation of UIT intensity. As the increase of UIT intensity, the maximum residual stress can reach −1085 MPa, located approximately 30 μm below the surface. And the corresponding maximum surface hardness can reach 561 HV 0.025. Microstructure elongation and extrusion intensification results in a maximum deformation layer depth of 9 μm, with a nanocrystalline layer on the outermost surface. The maximum average fatigue life is 6.431×106 cycles and the cracks initiate under the surface with quasi-cleavage as the initiation mode. As the cracks deepen, the stress intensity factor increases, and the crack shape eventually tends to be circular. Alterations in residual stress amplitude and depth do not influence the final crack shape. However, increased amplitude and depth can accelerate the consistency of the stress intensity factor outside the compressive stress region. • High-temperature fatigue tests at 400 ℃ were performed on UIT specimens with different surface states. • Alterations in residual stress amplitude and depth do not influence the final crack shape. • As the cracks deepen, the stress intensity factors outside the compressive stress region tend to be consistent. [ABSTRACT FROM AUTHOR]

Hematite (α-Fe 2 O 3) is considered as an ideal photoanode material in photoelectrochemical (PEC) water splitting system due to its suitable band gap, excellent stability and abundant reserves. However, the actual PEC water oxidation performance of α-Fe 2 O 3 is greatly limited by its severe charge recombination and sluggish water oxidation kinetics. Here, an in-situ generated Fe phosphate (Fe-Pi) coating strategy is applied on the surface of porous hematite nanocube (Fe 2 O 3 NC) to realize PEC water oxidation effectively. The obtained Fe-Pi/Fe 2 O 3 NC photoanode exhibits a remarkable PEC property with a photocurrent density of 2.7 mA cm−2 at 1.23 V vs. RHE, which was about 5.7-fold enlarged compared to the pristine nanorod-like hematite (Fe 2 O 3 NR) photoanode. Detailed studies have shown that the porous Fe 2 O 3 NC possesses an enhanced ability in light absorption and charge separation than the traditional Fe 2 O 3 NR photoanode. In addition, the in-situ loading of Fe-Pi layer as a co-catalyst can not only effectively passivate the surface trapping states of Fe 2 O 3 NC and suppress interfacial charge recombination, but also quickly extract the holes to participate in the water oxidation reaction. Our study suggests that the further surface modification based on morphological engineering is an effective strategy to improve the PEC performance of hematite. • Iron phosphate is formed in-situ on the surface of porous hematite nanocubes. • Porous hematite nanocubes have good light absorption and charge separation ability. • Iron phosphate passivates the surface state and accelerates water oxidation reaction. • Porous hematite nanocube and iron phosphate work together to improve PEC performance. [ABSTRACT FROM AUTHOR]