Amorphous Surface Research Articles

MgO/SiO2 prepared by wet-kneading as a catalyst for ethanol conversion to 1,3-butadiene: Prins condensation as the predominant mechanism

MgO/SiO2 catalysts prepared by wet-kneading with various compositions were applied to directly convert ethanol to 1,3-butadiene. The MgO/SiO2 molar ratio significantly affected the structural, textural, and surface properties of the catalysts, leading to different activities toward ethanol conversion. At low MgO loading (51 mol %), magnesium silicate is formed on the amorphous silica surface, resulting in a higher activity for ethanol dehydration to ethylene. Increasing the MgO loading, crystalline magnesium oxide is formed in addition to the magnesium silicate, producing strong basic sites capable of increasing the ethanol conversion to 1,3-butadiene. Interestingly, for the mixed oxides prepared herein, a linear correlation was found between the forward reaction rate for 1,3-butadiene formation as a function of the reaction rate for acetaldehyde and ethylene. This behavior suggests a predominance of the Prins condensation mechanism. Therefore, the paired arrangement and the strength of the acid-basic conjugate sites of these catalysts must be determinant for the dehydrogenation and dehydration of ethanol and the condensation of the respective intermediates acetaldehyde and ethylene to form 1,3-butadiene.

Investigating Mixed Cationic and Anionic Redox Chemistry in Chalcogen Based Cathodes for Li-Ion Batteries

Current state-of-the-art Li-ion batteries are reaching their theoretical limit with respect to the capacity, a property largely limited by cathode materials that have so far relied solely on cationic-redox of transition-metal ions (e.g., M3+/4+ in LiMO2 where M is Co, Ni, and Mn) for driving the electrochemical reactions. Recently, the introduction of new anion-redox cathode materials can lead to a doubling of capacity by accommodating multielectron redox chemistries that have gained research interest. (1) However, current anion-redox cathode materials based on Li-rich layered oxides (represented by the formula Li1+xM1-xO2 where M is Co, Ni, and Mn) suffer from voltage fade, large hysteresis, and sluggish kinetics, which originate mysteriously from the anionic redox activity of oxygen ligand itself. (2) It is widely accepted that the covalency between transition metal – oxygen ligand in traditional cathode materials needs to be altered to take advantage of anion redox chemistry. Here, we present an alternative approach of incorporating improved metal – ligand covalency by less electronegative chalcogen sulfur ligands in the cathode structural framework where the metal d-band penetration into ligand p-band thereby utilizing mixed anionic and cationic redox chemistry. (3) Through this design strategy, we investigated anion redox activity in layered cathode material based on Li2SnS3, and their lithiation/delithiation properties were evaluated through in-depth electrochemical analysis. Further, the charge contributors during electrochemical reactions were identified by spectroscopy analysis, and morphological evolution due to mixed anionic and cationic redox reactions were evaluated using high-resolution transmission electron microscopy(HR-TEM) and high annular dark field-scanning transmission electron microscopy(HAADF) investigations.The results reveal the multi redox induced structural modifications and its surface amorphization with nanopore formation during cycling. Findings from this research will inspire Ni and Co free chalcogen cathode design and various functional materials in the pursuit of next generation cathode materials.References J. R. Croy, M. Balasubramanian, K. G. Gallagher, A. K. Burrell, Review of the US Department of Energy’s “Deep Dive” effort to understand voltage fade in Li-and Mn-rich cathodes. Accounts of chemical research 48, 2813-2821 (2015). G. Assat, J. M. Tarascon, Fundamental understanding and practical challenges of anionic redox activity in Li-ion batteries. Nature Energy 3, 373-386 (2018). S. Nagarajan, S. Hwang, M. Balasubramanian, N. K. Thangavel, L. M. R. Arava, Mixed Cationic and Anionic Redox in Ni and Co Free Chalcogen-Based Cathode Chemistry for Li-Ion Batteries. Journal of the American Chemical Society 143, 15732-15744 (2021).

Electronic Structure Modulation of Sulfur-Retaining Nickel-Based Electrocatalyst to Improve the Oxygen Evolution Reaction

Water electrolysis is considered as a key energy source to produce hydrogen for achieving a clean and sustainable society. Improving the sluggish kinetics of the oxygen evolution reaction (OER) is focused to overcome the limit efficiency of water electrolysis. Transition metals, especially Ni, are one of the most promising materials for the alkaline OER because of good catalytic activities, stabilities and cost efficiency. Ni based materials, such as Ni oxyhydroxides, hydroxides, phosphides and sulfides, are intensively developed for use as OER catalysts. Recently, the sulfurization of transition metals is introduced as an effective method to improve the intrinsic electrocatalytic activities. The role of S has been summarized in 2 ways. S accelerates the regeneration of transition metals in alkaline media that S is dissolved and exchanged with O species. Mullins et al. reported Nickel oxide derived from Ni-S. It exhibits amorphous and large active surface morphology which is favorable OER. The other role is that remaining S modulates the electronic structures of Ni catalysts reducing the energy barrier for the OER. Wu et al. developed ultrathin Fe-doped Ni3S2 for overall water splitting. Based on density functional theory calculations, the Fe-doped Ni3S2 surface exhibits an optimized energy for water adsorption and dissociation, which enhances the intrinsic activity for the OER. However, in-situ/operando experimental studies regarding the effects of residual S are rare.Herein, we report the role of the remaining S in Ni catalysts that exhibit longer Ni-O bonding in the NiOOH phase produced in-situ. C-supported Fe- and Co-doped nickel sulfide catalysts (NiFeCo-S/C) is prepared using a simple impregnation method with heating under an H2S atmosphere. We tested the electrochemical properties of the NiFeCo-S/C in alkaline media of 1 M KOH. It achieved current density of 10 mA cm-2 with only overpotential of 267.2 mV. Also, it maintained the OER activities for 24 h at current densities of 10 and 50 mA cm-2, respectively. Moreover, the prepared catalyst was analyzed the change of electronic structure and bonding group using in-situ/operando X-ray absorption spectroscopy (XAFS) and surface-enhanced Raman spectroscopy (SERS) under OER condition. Based on these results, we could elucidate the effects of the remaining S during the OER. Figure 1

Binding Energies of Interstellar Relevant S-bearing Species on Water Ice Mantles: A Quantum Mechanical Investigation

Binding energies (BEs) are one of the most important parameters for astrochemical modeling determining, because they govern whether a species stays in the gas phase or is frozen on the grain surfaces. It is currently known that, in the denser and colder regions of the interstellar medium, sulfur is severely depleted in the gas phase. It has been suggested that it may be locked into the grain icy mantles. However, which are the main sulfur carriers is still a matter of debate. This work aims to establish accurate BEs of 17 sulfur-containing species on two validated water ice structural models, the proton-ordered crystalline (010) surface and an amorphous water ice surface. We adopted density functional theory-based methods (the hybrid B3LYP-D3(BJ) and the hybrid meta-GGA M06-2X functionals) to predict structures and energetics of the adsorption complexes. London’s dispersion interactions are shown to be crucial for an accurate estimate of the BEs due to the presence of the high polarizable sulfur element. On the crystalline model, the adsorption is restricted to a very limited number of binding sites with single valued BEs, while on the amorphous model, several adsorption structures are predicted, giving a BE distribution for each species. With the exception of a few cases, both experimental and other computational data are in agreement with our calculated BE values. A final discussion on how useful the computed BEs are with respect to the snow lines of the same species in protoplanetary disks is provided.

ОСОБЛИВОСТІ ФОРМУВАННЯ ПОВЕРХНЕВИХ ШАРІВ НА МЕТАЛАХ

The practical application of metal alloys, in particular amorphous ones, often necessitates the creation of multifunctional coatings of various nature and purpose on their surfaces. The main requirements for obtaining optimal results of applying such coatings are as follows: 1. Understanding of the morphology of the surface before coating. 2. Information on the physical and mechanical properties of the metal-coating composition. 3. Testing of the adhesion strength immediately after coating. 4. The use of different methods of control of the application and functionality of the coating, depending on the operating conditions of the product. The reliability of functional coatings also depends on the preparation of the surface of the material, as well as the choice of appropriate conditions for its formation. However, regardless of the purpose, a general requirement that all coatings must meet is a good adhesion to the surface of the substrate material. It is also important to ensure the uniform thickness in different areas (protrusions and depressions), because the thickness of the coating determines the longevity of its protective effect. Also, the coatings should have very low rate of dissolution even in the most aggressive environments in which they work. Therefore, the problem of creating optimal coatings is complex and requires a comprehensive study in each specific case. In the case of industrial use of amorphous metal alloys (AMA) based on transition metals with different alloying elements, special attention must be paid to the elemental composition of the surface of the finished products, which can differ significantly from the quantitative composition of the initial charge, which depends on the nature of the components and the applied protocol of ultra-fast cooling of the melt. The difference in the elemental composition on the surface and in the volume of the amorphous alloy is also due to the possible formation of surface chemical compound i.e. metal oxides. The protective properties are evaluated by the speed of metal oxidation, the formation of a layer and the duration of its action. Comparative assessment of the reactivity of amorphous alloys Al87.0Y5.0Ni8.0, Fe73.6Cu1.0Nb2.4Si15.8B1.2, Fe78.5Ni1.0Mo0.5Si6.0B14.0, Co75.5Fe4.6Si6,B16.7 in an aqueous solution of sodium chloride was carried out using electrochemical studies. The main requirements for obtaining optimal results of applying protective coatings on crystalline and amorphous surfaces have been analyzed.

Tuning amorphous Ir-IrOx oxygen evolution catalyst via precursor complexation for efficient and durable water electrolysis

Sluggish kinetics and corrosive condition of oxygen evolution reaction (OER) make it the bottleneck of proton exchange membrane water electrolyzer (PEMWE). It is essential to develop facile and scalable synthetic methods to elevate the activity and stability of OER electrocatalysts. We report a precursor complexation method to prepare a Ir-IrOx OER catalyst with crystalline Ir skeleton and amorphous IrOx surface. The appropriate valence states of amorphous IrOx surface and Ir skeleton were the probable origins of high activity and durability for OER by tuning the complexes and calcination temperature. An increasing calcination temperature and a complex with high decomposition rates led to more fractions of oxide surface as well as high valence state of Ir. The Ir-IrOx catalyst only required an overpotential of 228 mV to attain a current density of 10 mA cm−2, surpassing most reported Ir-based catalysts. A PEMWE equipped with the Ir-IrOx OER catalyst reached a current density of 1 A cm−2 at a low cell voltage of 1.67 V at 80 °C, and the applied voltage was almost unchanged in the 100 h’ chronopotentiometry test, suggesting the potential practicability of the catalysts.

Configuration of the surfaces of epithelial cells infected by human papillomavirus

Human papillomavirus (HPV) types were investigated hy iri situ hybridization (ISH) in biopsiesfroin J8patients with diverse pathologies ofcervix uteri (7 condylomas, 1 CINI +HPV, 3 CIN II, 4 CIN II + HPV and 3 CIN III). Cervical sniears ofthe same patients were processed by Scanning Electron Mycroscopy (SEM) in order to study the configuration of sitrfaces ofcells infected hy different HPV types. Seven condylomas, I CIN I + HPV, 3 CIN II and 3 CIN II + HPV showed alinost identical surface configurations to those of normal cells (short, thin, homogeneous microvi lli o r typicai microridgesj. This group presented low, moderate and high risk HPV types in a episomal form, while I CINII + HPV and3 CINIII with integratedHPV 16/]8 exfoliatedcells covered with gross microvilli, with variahle length and uneven distribution, oran amorphous surface. The presence of HPV 16/18 cannot be sufficient for the development of an anormal configuration, hut the integrated State ofthis viral type coiild he related to the morphological changes in cellular surface morphology. The results of this paper underline the importance of viral integration in the genesis of cervical carcinoma.

Alcohol Plasma Processed Surface Amorphization for Photocatalysis

Alcohol Plasma Processed Surface Amorphization for Photocatalysis

Machine learning accelerated DFT research on platinum-modified amorphous alloy surface catalysts

Pt-modified amorphous alloy (Pt@PdNiCuP) catalyst exhibits excellent electro-catalytic activity and high experimental durability for hydrogen evolution reaction (HER). However, the physical origin of the catalytically active remains unclear. In this paper, we constructed a distance contribution descriptor (DCD) for the feature engineering of machine learning (ML) potential, and calculated the Gibbs free energies (ΔGH) of 46,000 *H binding sites on the Pt@PdNiCuP surface by ML-accelerated density functional theory (DFT). The relationship between ΔGH and DCD revealed that in the H-Pt distance region of 2.0–2.5 Å where the parabolic tail and disordered scatters coexist, the H-metal bonding configuration is mainly the bridge- or hollow- bonding type. The contribution analysis of DCD indicates that the joint effect of Pt, Pd and Ni atoms determines the catalytical behavior of amorphous alloy, which agrees well with experimental results. By counting atomic percentages in different energy intervals, we obtained the atomic ratio for the best catalytic performance (Pt:Pd:Ni:Cu:P = 0.33:0.17:0.155:0.16:0.185). Projected density of states (PDOS) show that H 1s orbital, Pt 5d orbital, and Pd 4d orbital form a bonding state at −2 eV. These results provide new ideas for designing more active amorphous alloy catalysts.

Metal-organic framework-derived mixed-phase anatase/rutile TiO2 towards boosted lithium storage: Surface engineering and design strategy through crystal phase transition

The design and construction of electrodes with surface and interface structures bring new opportunities for high-performance lithium storage properties. Herein, we present a simple synthesis method to fabricate surface-amorphized anatase/rutile mixed-phase truncated octahedral TiO2 (TO-AR) structures with oxygen vacancy derived from metal-organic framework (MOF) with a temperature-controlled phase transition. Compared with single-phase TiO2, the mixed-phase TO-AR electrode shows higher specific capacity and better rate performance. Systematic experimental studies and theoretical calculations demonstrate that the abundant interface between anatase and rutile induced by the crystallographic phase transition provides efficient high-capacity Li+ storage and enhanced charge-transfer kinetics. Meanwhile, the amorphous surface and higher oxygen vacancy concentration improve the surface-induced capacitive properties. These results provide new insights into improving the electrochemical performance of metal-organic framework-derived anode materials in Li-ion batteries.

Molecular Dynamics Simulations on Effect of Surface Roughness of Amorphous Substrate on Nucleation in Liquid Al

In this study, we used molecular dynamics (MD) simulations to investigate the atomic ordering in the liquid aluminum (Al) adjacent to the amorphous substrate with smooth and rough surfaces. This study revealed that the liquid exhibited layering within about 5 atomic layers but no visible in-plane atomic ordering at the interface with the smooth amorphous surface, and neither layering nor in-plane atomic ordering with the rough surface of the amorphous substrate. However, the smooth amorphous surface induced some local ordered structure in the liquid at the interface by a structural templating mechanism, which promoted heterogeneous nucleation by creating a 2-dimensional (2D) nucleus in the third layer. The amorphous substrate with a rough surface had no effect on the nucleation in the liquid, leading to the occurrence of homogeneous nucleation with an undercooling 100 K larger than that of heterogeneous nucleation on the smooth amorphous substrate. This study confirmed that structural templating is a general mechanism for heterogeneous nucleation.

THE OCCURRENCE OF BONE MODIFICATION FEATURES IN THE CARAPACE AND PLASTRON OF THE EXTANT RED-EARED SLIDER TRACHEMYS SCRIPTA ELEGANS (WIED-NEUWIED, 1839): IMPLICATIONS FOR PALEOECOLOGICAL ANALYSES OF FOSSIL TURTLE ASSEMBLAGES

Abstract The carapace and plastron bones of fossil turtles are often characterized by bone modification features such as pits, grooves, and holes. The significance, origin, and frequency of these features remains unclear because they have not been described from the bones of modern turtles. Taxon-specific description and analyses of defleshed turtle shell is essential for assessing the paleoecological significance of bone modification features. This study focuses on bone modification features on carapace and plastron bones of the emydid turtle Trachemys scripta elegans. Four subadult and 14 adult turtle shells were examined for non-ontogenetic features such as pits, grooves, holes, wounds, abrasions, and pathological growth structures. Bone modification features were lacking on subadult specimens but observed on each adult. Shallow, circular to subcircular pits (similar to the ichnotaxon Karethraichnus lakkos), and to a lesser extent pit clusters, are the most common feature noted on T. scripta elegans shells. Although they occur on both the plastron and the carapace, they proved far more common on the lower shell. Sparsely distributed ring-shaped grooves similar to the ichnotaxon Thatchtelithichnus holmani were present on approximately half of the turtle plastra studied. Amorphous surface etching was observed on several turtles, most commonly near the plastron midline (posterior portion of the hyoplastron/anterior portion of the hypoplastron). Pathological responses to these marks are lacking, but were noted on two turtles in response to sustained injuries. The occurrence of circular and subcircular pits, pit clusters, and ring traces on the external surface of every adult turtle analyzed in this study (regardless of sex or geographical occurrence), their discrete size and shape, and the lack of evidence of a systemic pathological response by the host suggests parasites, possibly leeches, as the etiological agent responsible for these features.

Nanostructured back surface amorphization of silicon with picosecond laser pulses

Laser-based amorphization on the back surface of a 525-μm thick crystalline silicon sample is studied. To deposit sufficient energy for a local change from a crystalline to an amorphous state, laser irradiation at 2-μm wavelength with 25-ps pulse duration is combined with Bessel beam shaping. Deterministic single-site modifications and homogeneous continuous lines of amorphous silicon are demonstrated. Optical and electron microscopy together with Raman spectroscopy measurements highlight the material transformations featuring the formation of subwavelength periodic surface structures. The investigations open up possibilities for processing in-built microelectronic devices.

Surface amorphization and nanocrystallization of the gradient-structured copper by explosive impact treatment

In this study, surface treatment on pure copper plates is carried out by an explosive impact technique. The gradient structures were successfully produced along the depth of plates near the impacted surface. It is found that both amorphous state and nano-grains with an approximate size of 10 nm are generated at the topmost surface after explosive impact treatment. The corresponding microhardness at the topmost surface is 4.35 times that of the annealed sample. Moreover, it is found that the microhardness decreases along depth of the specimen gradually. The calculation results demonstrate that amorphization and nanocrystallization on the topmost surface are closely related to the rapid temperature rise and cooling rate. This work provides experimental evidence that the explosive impact treatment is a potential technology of surface treatment to produce a surface amorphous state.

Low-resistivity, high-resolution W-C electrical contacts fabricated by direct-write focused electron beam induced deposition.

Background: The use of a focused ion beam to decompose a precursor gas and produce a metallic deposit is a widespread nanolithographic technique named focused ion beam induced deposition (FIBID). However, such an approach is unsuitable if the sample under study is sensitive to the somewhat aggressive exposure to the ion beam, which induces the effects of surface amorphization, local milling, and ion implantation, among others. An alternative strategy is that of focused electron beam induced deposition (FEBID), which makes use of a focused electron beam instead, and in general yields deposits with much lower metallic content than their FIBID counterparts. Methods: In this work, we optimize the deposition of tungsten-carbon (W-C) nanowires by FEBID to be used as electrical contacts by assessing the impact of the deposition parameters during growth, evaluating their chemical composition, and investigating their electrical response. Results: Under the optimized irradiation conditions, the samples exhibit a metallic content high enough for them to be utilized for this purpose, showing a room-temperature resistivity of 550 μΩ cm and maintaining their conducting properties down to 2 K. The lateral resolution of such FEBID W-C metallic nanowires is 45 nm. Conclusions: The presented optimized procedure may prove a valuable tool for the fabrication of contacts on samples where the FIBID approach is not advised.

Understanding the activity decay of MnO2 for oxygen reduction in neutral media

MnO 2 has been studied as the catalyst for oxygen reduction reaction (ORR) in neutral due to its considerably good performance and low cost. Although many studies focus on activity enhancement, little attention has been paid to the activity degradation of MnO 2 . In this study, we first probe the mechanism of ORR activity decay of MnO 2 catalyst in neutral. Electrochemical measurements showed the apparent activity degradation of MnO 2 in both short-term and long-time stability tests. After chronoamperometry test, surface amorphization was observed on the catalyst, while no significant amorphization occurred for the absence of ORR catalysis. The activity decay and surface amorphization of MnO 2 catalyst are due to the disproportionation reaction of Mn 3+ ions in neutral. Mn 3+ ions involved in ORR catalysis disproportionate to generate soluble Mn 2+ ions, resulting in the surface amorphization together with the change of the highly ORR-active Mn 3+ /Mn 4+ redox to the low ORR-active Mn 2+ /Mn 3+ redox. This study clarifies the activity decay mechanism of MnO 2 for ORR in neutral media and provides theoretical support for improving and stabilizing the catalytic activity of MnO 2 in the future. The disproportionation reaction of Mn 3+ ions under neutral conditions destroys the redox conversion between Mn 3+ and Mn 4+ . • The ORR activity of MnO2 catalyst decays quickly in neutral. • The activity decay comes along with surface amorphization. • Surface amorphization is resulted by the disproportionation of Mn 3+ ions. • The loss of Mn 4+ converts highly active Mn 3+ /Mn 4+ to low active Mn 2+ /Mn 3+ .

Dependency of CO2 methanation on the strong metal-support interaction for supported Ni/CeO2 catalysts

The strong metal-support interaction (SMSI) for supported Ni/CeO2 catalysts with different CeO2 nanomorphologies was systematically explored. The degree of encapsulation of Ni particles originating from the SMSI effect was found to follow the trend of Ni/CeO2-(111) > Ni/CeO2-(100) > Ni/CeO2-(110 + 100), which parallels the CO2 hydrogenation activity. Quasi in situ XPS reveals the presence of Ce3+ sites in accordance with the formation of an amorphous surface CeOx layer encapsulating the Ni nanoparticles. In situ DRIFTS indicates the reaction pathway and rate-determining step are dependent on the degree of the SMSI effect, leading to distinct selectivities towards CH4, especially at a high weight hourly space velocity (WHSV). These findings present a fundamental strategy about tailoring catalytic performance through support facet dependent susceptibility of SMSI phenomena.

Titanium Phosphate Grafted on Mesoporous SBA-15 Silica as a Solid Acid Catalyst for the Synthesis of 5-Hydroxymethylfurfural from Glucose

The grafting of titania on SBA-15 followed by its phosphation was presented to prepare a mesoporous Lewis–Brønsted bifunctional solid acid catalyst for the tandem conversion of glucose via fructose to 5-hydroxymethylfurfural (HMF). Titania was dispersed on SBA-15 as an amorphous surface layer containing abundant coordinatively unsaturated tetrahedral Ti ions, which was reactive and readily transformed upon phosphation into a new titanium phosphate phase with the chemical formula identified as Ti2O3(H2PO4)2·2H2O. The ordered mesoporous structure was well maintained after three modification cycles, affording a desirable surface area of over 300 m2/g. The SBA-15-supported titanium phosphate layer affords higher overall acidity and Brønsted to Lewis acid ratio, compared with the conventional post-phosphated bulk anatase titania. The tetrahedral Ti ions and the adjacent protonated phosphate groups on the titanium phosphate layer could form Lewis–Brønsted acid pairs at molecular level proximity, which largely enhanced the selective tandem catalysis for glucose conversion via fructose to HMF. An optimized HMF yield of 71% was achieved at 160 °C in a water–methyltetrahydrofuran biphasic system over the SBA-15-supported titanium phosphate catalyst. The catalyst exhibited good hydrothermal stability with a rather limited silicon and phosphate leaching, and no distinct pore collapse or performance loss over three sequential reaction runs.

Dual Role of Au nanoparticles in the Catalytic Formation of an Amorphous Polynuclear Peroxo Complex and Surface Enhanced Resonance Raman Scattering

AbstractWe report the catalytic formation of bridged polynuclear peroxo complex of Co(II) and 2‐picolylamine (2‐PA) in aqueous alkaline medium on the surface of Au nanoparticle. The reaction followed sigmoidal kinetics both in absence and presence of the Au nanoparticle with an order of magnitude higher rate constant in the presence of nanoparticle. Importantly, using UV‐Vis spectroscopy, mass spectrometry and surface enhance resonance Raman scattering (SERRS), we conclude the formation of peroxo complex with 2‐PA acting as a monodentate ligand. The absorbance of the polynuclear complex at 595 nm and the extinction maximum of (agglomerated) the Au nanoparticles at 750 nm provided the right opportunity to pursue SERRS using 632.8 nm laser excitation. Density functional theoretical calculation indicated that the lowering of HOMO‐LUMO energy gap of 2‐PA bonded to the nanoparticle surface helped catalyze the reaction.

Research on mechanism of ultrasonic-assisted nano-cutting of sapphire based on molecular dynamics

Ultrasonic vibration grinding improves the surface quality and processing efficiency of sapphire machining compared with conventional grinding, but its nano-scale deformation mechanism is still unclear. In this study, the molecular dynamics method was used to simulate the ultrasonic vibration cutting of a single abrasive grain along the [010] direction on the sapphire (0001) surface to study the effects of different vibration directions, amplitudes and frequencies on the cutting force, stress, temperature, number of amorphous atoms, surface morphology and subsurface damage layer. The results show that the tangential and radial vibration cutting reduces the tangential force, normal force and total force compared with conventional cutting. At the same time, it is also found that different vibration directions have different effects on material removal efficiency and subsurface damage depth. In the material removal efficiency, the radial vibration cutting has the highest removal efficiency, and the tangential vibration cutting and conventional cutting have the same removal efficiency. In the subsurface damage depth, the subsurface damage depth in tangential vibration cutting is the smallest, the subsurface damage depth in conventional cutting is the second, and the subsurface damage depth in radial vibration cutting is the largest.