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Statement of problem Whether procedures performed before the cementation of computer-aided design and computer-aided manufacturing (CAD-CAM) glass-ceramic restorations, including milling, fitting adjustment, and hydrofluoric acid etching introduce defects on the ceramic surface that affect the mechanical and surface properties is unclear. Purpose A systematic review and meta-analysis were conducted to assess the effect of milling, fitting adjustments, and hydrofluoric acid etching (HF) on the flexural strength and roughness (Ra) of CAD-CAM glass-ceramics. Material and methods Literature searches were performed up to June 2020 in the PubMed/MEDLINE, Web of Science, and Scopus databases, with no publication year or language limits. The focused question was “Do milling, fitting adjustments, and hydrofluoric acid etching affect the flexural strength and roughness of CAD-CAM glass-ceramics?” For the meta-analysis, flexural strength and Ra data on milling, fitting adjustment, and HF etching versus control (polishing) were analyzed globally. A subgroup analysis assessed the effect of etching parameters (HF concentration and time) on the flexural strength and roughness of CAD-CAM glass-ceramics with different microstructures. Comparisons were performed with random-effect models at 5% significance. Results Fourteen studies from 2764 potentially relevant records were included in the qualitative syntheses, and 12 in the meta-analysis. Milling and fitting adjustments increased roughness and reduced the flexural strength of CAD-CAM glass-ceramics. The effect of HF etching was dependent on the glass-ceramic microstructure, HF concentration, and etching time. For feldspathic- and leucite-reinforced ceramics, HF 5% applied for between 30 and 120 seconds increased roughness without affecting flexural strength. For lithium disilicate glass-ceramics, HF concentrations greater than 4.9% used for 20 seconds or more reduced the strength without affecting the surface roughness. Conclusions The flexural strength of CAD-CAM glass-ceramic is reduced by grinding procedures such as milling and fitting adjustment. Ceramic microstructure, HF concentration, and etching time determined the effect of hydrofluoric acid etching on the flexural strength and surface roughness of glass-ceramic materials.

Synthetic two-dimensional (2D) mono-elemental crystals, namely X-enes, have recently emerged as a new frontier for atomically thin nanomaterials with on-demand properties. Among X-enes, antimonene, the β-phase allotrope of antimony, is formed by atoms arranged in buckled hexagonal rings bearing a comparatively higher environmental stability with respect to other players of this kind. However, the exploitation of monolayer or few-layer antimonene and other 2D materials in novel opto-electronic devices is still hurdled by the lack of scalable processes. Here, we demonstrated the viability of a bottom-up process for the epitaxial growth of antimonene-like nanocrystals (ANCs), based on a Metal-Organic Chemical Vapor Deposition (MOCVD) process, assisted by gold nanoparticles (Au NPs) on commensurate (1 1 1)-terminated Ge surfaces. The growth mechanism was investigated by large- and local-area microstructural analysis, revealing that the etching of germanium, catalyzed by the Au NPs, led to the ANCs growth on the exposed Ge (1 1 1) planes. As a supportive picture, ab-initio calculations rationalized this epitaxial relationship in terms of compressively strained β-phase ANCs. Our process could pave the way to the realization of large-area antimonene layers by a deposition process compatible with the current semiconductor manufacturing technology.

Due to its high theoretical capacity and appropriate potential platform, tin-based alloy materials are expected to be a competitive candidate for the next-generation high performance anodes of lithium-ion batteries. Nevertheless, the immense volume change during the lithium-ion insert process leads to severe disadvantages of structural damage and capacity fade, which limits its practical application. In this work, a three-dimensional (3D) multicore-shell hollow nanobox encapsulated by carbon layer is obtained via a three-step method of hydrothermal reaction, annealing and alkali etching. During the electrochemical reactions, the CoSn@void@C nanoboxes provide internal space to compensate the volumetric change upon the lithiation of Sn, while the inactive component of Co acts as chemical buffers to withstand the anisotropic expansion of nanoparticles. Owing to the above-mentioned advantages, the elaborated anode delivers an excellent capacity of 788.2 mAh/g at 100 mA/g after 100 cycles and considerable capacity retention of 519.2 mAh/g even at a high current density of 1 A/g after 300 cycles. The superior stability and high performance indicate its capability as promising anodes for lithium-ion batteries.

The effect of the oxidizer present in the etching solution on the surface morphology and microstructure obtained after porosifying a p-type silicon wafer using metal-assisted chemical etching was studied. The morphologies of Si wafers porosified using two different solutions, HF/H2O2 and HF/KMnO4, were compared to establish how either of the oxidizers (H2O2 or KMnO4) should be chosen depending on the desired application. A comparative study revealed that parallel pores with wire-like structures or interconnected pores with cheese-like structures can be obtained when H2O2 or KMnO4 are chosen, respectively. Careful analysis of the SEM images was carried out using ImageJ to establish that the samples prepared using KMnO4 are more porous due to aggressive etching. Additionally, experimental and theoretical Raman spectroscopic studies have been utilized to study the presence of low-dimensional Si nanostructures, which are a few nanometers in size, at the microscopic level in porosified silicon.

Statement of problem Dental implants undergo various surface treatments. Studies that have characterized their surface and subsurface by using the same methods are scarce. Purpose The purpose of this study is to physically characterize the surface and subsurface of implant systems made of commercially pure (cp) titanium (Ti) grade (gr) 4 and Ti alloy gr 23 and to evaluate whether airborne-particle abrasion and acid etching is an appropriate surface treatment for Ti alloy gr 23. Material and methods Implant groups (n=3) were as follows: TG4AO, cp Ti gr 4, treated with anodic oxidation (3.5×8 mm) (NobelReplace Conical; Nobel Biocare); TG23AE, Ti gr 23 (TiAlV ELI) airborne-particle abraded-and-etched (3.9×8 mm) (V3; MIS); and TG4AE, cp Ti gr 4, airborne-particle abraded and etched (3.3×8 mm) (BL; Institut Straumann AG). Surface roughness, surface topography, and elemental and surface composition were investigated with optical profilometry, scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction. The presence and size of Ti hydride (TiH) needles were determined on metallographic sections. Depth profiling was obtained by time-of-flight secondary ion mass spectrometry (ToF-SIMS) to determine possible enrichment of an alloying element at the implant surface. Results The mean arithmetic deviation roughness (Sa), of TG4AO was 0.80 μm. The Sa of TG4AO was 1.22 μm, and the Sa of TG4AO was 1.59 μm. The difference between the groups was significant (P Conclusions The roughness, topography, and composition of the surfaces were different for all implants tested. Airborne-particle abrasion and subsequent etching was an appropriate treatment for Ti gr 23 alloy implants.

Transition-metal phosphides have been of concern as efficient electrocatalysts for oxygen evolution reaction (OER) due to its high conductivity and earth-abundance reserves. However, oxide overlayers formed on their surface by spontaneously atmospheric oxidation are usually neglected, thus confusing the establishment of structure–performance relationship. Herein, we successfully etched the oxide overlayers of NiFe phosphide (NiFeP) by a dielectric barrier discharge (DBD) plasma technique, aiming to reveal the influence of the oxide overlayers on its electrocatalytic performance for OER. It is found that etching the oxide overlayers can accelerate the surface reconstruction process of NiFeP and facilitate the formation of metal hydroxides, which are key intermediate phases for OER. Consequently, the etched NiFeP-DBD material shows remarkably enhanced OER activity with an overpotential of 265 mV at a current density of 10 mA/cm2. The finding of this work probably brings a significant impact to understand the structure–performance relationship of metal phosphide in electrooxidation reaction.

A facile and mild route to synthesize C-coated SiC nanosheets (SiC/C NSs) via wet-chemical etching in hydrofluoric acid (HF) at 60 °C for 48 h using carbon aluminum silicate (Al4SiC4) as raw materials is reported for the first time. HF molecule leads to the breaking of C-Al bonds in Al4SiC4, which eventually results in the formation of two-dimensional SiC nanosheets. A carbon layer with a thickness of approximately 1.5 nm is formed on the surface of SiC nanosheets due to the excess carbon. The prepared SiC/C NSs possess a smooth and rectangular sheet with a mean 150 nm in width, 500 nm in length and 10 nm in thickness, respectively. The crystallographic characterization indicates that 3C-SiC and 2H-SiC coexist and the parallel plane relationship of 3C/2H-SiC heterojunction is (111)3C-SiC//(001)2H-SiC. Due to the formed 3C-SiC/2H-SiC heterojunction and graphitic carbon, the fabricated electrode based on SiC/C NSs exhibits prolonged cycling stability and high specific areal capacitance as a promising supercapacitor candidate. It remains 91.2% retention even after 20000 cycles and 734 μF/cm2 at a scan rate of 10 mV/s.

Dielectric polarization performance induced by defect engineering approach has been proved to be an effective way for improving the microwave absorption property of carbon-based materials. Assisting by the solid-state reaction, the structural integrity of multi-walled carbon nanotubes (MWCNTs) would be broken along with the volume expansion and etching process of cobalt oxides. Therefore, the defects could be obtained and result in the enhancement of microwave absorption property. Ascribing to the broken wall structures, the defect-distances (LD) and concentrations (nD) have been optimized to be 9.80 nm and 3.37 × 1011 cm−2. The minimum reflection loss (RL) had reached -54.6 dB at 4.5 GHz with a thickness of 4.13 mm and the corresponding effective absorption bandwidth (EAB

PURPOSE To assess the shear bond strength of composite resin to polyether ether ketone (PEEK) after mechanical and chemical surface treatments. MATERIALS AND METHODS A total of 48 PEEK discs were fabricated and divided equally into four surface treatment groups (n = 12 each): (1) airborne particle abrasion with 50-μm alumina particles at 2 MPa pressure for 10 seconds; (2) 98% sulfuric acid etching for 1 minute; (3) airborne particle abrasion and sulfuric acid etching; and (4) no surface treatment. Specimens were conditioned, then Gradia composite veneer (GC) was applied to the PEEK surfaces and polymerized. Bond strength was measured with shear bond test using a universal testing machine. One-way analysis of variance and Tukey post hoc tests were applied for statistical analysis. RESULTS The mean shear bond strength values of the sulfuric acid-etched group were higher than that of the airborne particle abrasion + acid etching, airborne particle abrasion, and control groups (P < .05). Mean shear bond strength values for the airborne particle abrasion + acid etching samples were higher than for the control and airborne particle abrasion groups (P < .05). CONCLUSION There was no significant difference between the samples treated with airborne particle abrasion and the control group.

Currently, the development of high-efficiency electromagnetic wave (EMW) absorbing materials has received close attention. Due to unique composition and structure, porous hollow carbon spheres (PHCSs) have been extensively studied in the EMW absorption field. In order to obtain the regulated EMW absorber, in the present study, sulfur was successfully doped into the PHCS by hydrogen peroxide etching and high temperature vulcanization. By fixing the amount of sulfur doped and the etching time, the micro-structure of the product could be effectively controlled, and the corresponding electromagnetic parameters would also change accordingly. The optimized sulfur-doped porous hollow carbon sphere (SPCHS) had the minimum reflection loss (RL) value of −27.2 dB, and the effective bandwidth of 4.76 GHz. More importantly, the best effective bandwidth (EAB, RL

In this study, water-dispersible graphitic carbon nitride (g-C3N4) photocatalysts were successively prepared through the chemically oxidative etching of bulk g-C3N4 that was polymerized thermally in different calcination atmospheres such as air, CO2, and N2. The different calcination atmospheres directly influenced the physicochemical and optical properties of both bulk and water-dispersible g-C3N4, changing the photocatalytic degradation behavior of methylene blue (MB) and tetracycline hydrochloride (TC-HCl) for water-dispersible g-C3N4. The bubble-burst process in the thermal polymerization of thiourea produced defective edges containing C=O groups that preferred substituting the C-NHx groups over bulk g-C3N4. In the oxygen-free N2 atmosphere among the different calcination atmospheres, more C=O functional groups were generated on the defective edges of bulk g-C3N4, resulting in the highest N vacancy of the tri-s-triazine structure. During the successive chemical oxidation, S- or O-containing functional groups were introduced onto water-dispersible g-C3N4. The water-dispersible g-C3N4 photocatalyst from the oxygen-free N2 atmosphere (NTw) contained the most O- and S- functional groups on the g-C3N4 surface. Consequently, NTw exhibited the highest photocatalytic activity in the MB and TC-HCl photodegradation because of its slowest recombination process, which was ascribed to the unique surface properties of NTw such as abundant functional groups on the defective edges and N-deficient property.

In this paper, a new method for pesticide detection based on porous silicon microcavities was proposed. First, the aptamer of acetamiprid was fixed in the functionalized porous silicon microcavity. Then, the complementary strand of the aptamer modified with graphene quantum dots was hybridized with the aptamer, and the effective refractive index of the porous silicon microcavity increased. When acetamiprid was added, it bound to the aptamer due to its stronger specificity. The aptamer separated from the complementary strand of the coupled graphene quantum dots and bound to acetamiprid, resulting in a decrease in the effective refractive index, and its central wavelength of reflection spectrum was blue shifted, and the blueshift increased with the increase of acetamiprid concentration. The relationship between the change in central wavelength and the concentration of acetamiprid was analysed, and the detection limit of acetamiprid was 151 nm.

Nowadays, in the practical application of microwave absorption, it is still urgent and challenging to develop the microwave absorber with broadened bandwidth at a single thickness. Constructing composites with multi-component and multi-structure has been an effective strategy to obtain enhanced microwave absorption performance. Herein, yolk-shelled Co@SiO2@Mesoporous carbon (Co@SiO2@MC) microspheres were prepared by in-situ one-pot synthesis, carbonization reduction, and subsequent etching. The mesoporous carbon shell and hollow cavity structure were obtained simultaneously by controlling the etching of SiO2. The large carbon-air interface in the mesoporous shell and interior voids extend the propagation path of electromagnetic wave and enhance scattering. Owing to strong dielectric/magnetic loss, synergistic effect between different components and microstructures, as well as excellent impedance matching, Co@SiO2@MC microspheres exhibit desirable microwave absorption performance. Notably, for the sample with mesoporous carbon shell thickness of 25 nm, the effective absorption bandwidth (reflection loss below −10 dB) is as wide as 9.6 GHz (8.4–18 GHz), completely covering the whole X and Ku bands at 3.7 mm. The ultra-wide absorption bandwidth of the yolk-shelled Co@SiO2@MC microspheres highlight their potential application in the field of microwave absorption. Furthermore, this work provides new insights for the preparation of multi-component/multi-structure microwave absorbers.

A physicochemical mechanism acting between the reactive plasma and the material surface controls the erosion of polycrystalline ceramics in fluorine containing etching plasmas. In this study, a Y2O3/YOF composite was exposed to a fluorine etching plasma. Relocalization enables the direct correlation of crystalline orientation with material response. Our study reveals an orientation dependent surface fluorination of Y2O3, which controls the etching resistance and morphology formation. Orientations near the low index planes (001), (010) and (100) exhibit the lowest stability due to a homogeneous surface reaction. The presented results help to extend the mechanistic understanding of the plasma-material interaction of Y2O3.

We are presenting here fabrication of silicon (Si) nanowires (NWs) arrays by using Si (1 0 0) wafer as substrate, by metal assisted chemical etching (MACE) method. The Si-NWs growth on the Si wafer has been done by using etching time of 45 min in etching solution of hydrogen fluoride and hydrogen peroxide. X-ray diffraction (XRD) has been used for the structural analysis of NWs to estimate the crystalline size, micro-strain, dislocation density of fabricated nanostructures. The surface morphology of Si-NWs array has been studied through field effect scanning electron microscopy (FE-SEM). The optical properties like energy band gap of fabricated Si-NWs has been carried out through UV–Vis diffuse reflectance spectroscopy (UV DRS) and photoluminescence (PL) spectroscopy.

Superhydrophobic surfaces have great potential for applications in electric power equipment, photovoltaic cell panels, and other fields due to their unique self-cleaning and dry storage characteristics. However, the common process for preparing superhydrophobic surfaces faces the following problems: complex preparation process, high cost, and easily damaged hydrophobic surface structure. In this study, a self-growing monoclinic phase of BaAl2Si2O8 glass-ceramics with a microscale structure is used as a matrix, which was etched with hydrofluoric acid and then treated with 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane to obtain a kind of superhydrophobic surface with a contact angle more than 150°. The effect of the etching time on the hydrophobicity and the micromorphology of the glass-ceramic surface is analyzed. The results show that the contact angle first increases, then stabilizes, and finally decreases with increasing etching time. This etched structure has a large number of bulges and voids, and parts of the surface hydrophobic groups stay away from direct contact with other objects. Thus, it protects the internal hydrophobic group and improves the mechanical stability of the superhydrophobic surface. This study offers a simple and inexpensive idea for the mass production of ceramic-based superhydrophobic materials.

This paper presents the results of an in-depth study of the plasma-chemical etching (PCE) process of single-crystal silicon carbide (SiC) in SF6/O2 inductively coupled plasma (ICP). Using the method of optical emission spectroscopy (OES) we have examined the influence of RF power, bias voltage, pressure in the reaction chamber, and gas mixture composition on SiC PCE as well as the applicability of the OES technique for optimization and monitoring of SiC dry etching process in SF6/O2 ICP. An optimized PCE process for mass-manufacturing of SiC diaphragms of less than 20 μm thickness with an etch rate of more than 1.2 μm/min, and with an Rms of the etched surface of about 0.7 nm is developed. The influence of microtrenches on the electromechanical characteristics of the diaphragm as part of a capacitive pressure sensor is studied by means of computational simulation. An ideal diaphragm is compared with a real-process produced diaphragm with the microtrenching effect. It was shown that this effect has a great impact on the mechanical characteristics of the diaphragm. It is demonstrated that the von Mises stress at an applied pressure of 0.2 MPa for the real diaphragm is 183 MPa, while for the ideal diaphragm only 88 MPa.

In this work we have analyzed the doping, passivation and contact properties of boron-doped (p+) polysilicon (poly-Si) layers to understand the two key limiting factors for industrial adoption of p+ poly-Si based passivated contacts: challenges with diffusion and challenges with screen-printed, fire-through (FT) metallization. Investigation of test samples with ex-situ doped poly-Si layers of varying thickness and surface morphologies revealed that sheet resistance (Rsheet) and passivation quality in ex-situ doped poly-Si are limited by the maximum solid solubility of boron in silicon, and possible damage to the interfacial silicon oxide (iOx) layer and increased Auger recombination at high diffusion temperatures, respectively. An interesting correlation is found between the maximum dopant density at the interface and the J0,pass, with the latter increasing with increasing dopant density. The contacts to p+ poly-Si layers are formed with commercially available FT Ag/Al pastes by screen printing process. Metal contact properties strongly depend on the surface morphology and thickness of poly-Si layer. Lower contact resistivity was achieved on textured surface with thickest poly-Si layers, while lowest recombination under metal contacts was achieved with planar surface with thickest poly-Si layer. Further microstructure analysis of metallized interfaces using Scanning electron microscope shows partial etching of thick (220 nm) poly-Si layers and near complete etching of thin (20 nm) poly-Si layers by FT Ag-Al pastes. Using optimized doping and contact conditions, excellent surface passivation in unmetallized regions (J0,pass of 3.8 fA/cm2), contact resistivities as low as 1.2 ± 0.8 mΩ-cm2 and recombination current densities under the metal contacts of 155 ± 10 fA/cm2 are achieved on textured and planar samples respectively.

The precise machining of silicon carbide composite (SiC–SiC) as a high-tech material with extraordinary characteristics is required for different applications in aerospace, light weight construction and car industry. Laser machining enable new approaches for fabrication processes but the regularly applied ablation processes can cause damage to the SiC–SiC material. Here we propose and demonstrate a new approach for gentle SiC–SiC machining making use of a laser-induced plasma for reactive species generation enabling chemical material removal processes. A fs-laser (775 nm, 150 fs, 1 kHz) was focussed to a CF4/O2 gas mixture igniting a laser-induced plasma (LIP) approximately 100 μm in front of a SiC–SiC sample. This LIP initiate material removal processes of the textured, multiphase SiC–SiC sample without a mechanical damage of the SiC–SiC composite structure. Different surface features such as etching of the cover SiC layer, etching of the SiC matrix and exposure, thinning and sharpen of the SiC fibres, underetching of the fibres has been observed. Across the whole etched area, no mechanical damage such as cracks, delamination's, broken fibres were observed so that a gentle machining process can be expected.

Partially-etched V2Al1-xCTz ceramic with the average particle of ∼400 nm was synthesized by etching submicro-sized V2AlC with 40 wt% HF at room temperature (RT) for 48 h and 72 h, respectively. V2Al1-xCTz etched for 72 h has exhibited higher charge-discharge property, with an average reversible discharge capacity of 349.2 mAh·g-1 at 0.1 A g-1 in the 120 cycles for lithium-ion batteries. The electrochemical performances of V2Al1-xCTz could be improved by the addition of carbon nanotubes (CNTs), graphene (GF) and titanium suboxides (Ti4O7) conductive additives, among which CNTs exhibit the best effectiveness with a capacity of ∼460 mAh·g-1 at 0.1 A g-1 in the 140 cycles and a capacity retention of ∼72% at 0.5 A g-1 after 400 cycles.

Purpose: This study sought to compare enamel surface morphology and orthodontic bracket re-bonding strength after phosphoric acid- or erbium-doped yttrium aluminum garnet (Er:YAG) laser-mediated re...

In this work, vertical micromirrors that are fabricated using deep etching of silicon followed by metal sputtering are studied. Physical parameter extraction methodology, image processing, machine learning and discrete element analysis are used to extend the easy-to-take scanning electron microscope images into 3-D topographical information, that are usually obtained using atomic force microscope and transmission electron microscope. The experimental results show that vertical micromirrors surface quality has a granular nature showing degraded performance and a different optical response with respect to the bulk metal. A physical model is developed and validated by comparing the measured reflectivity of the fabricated micromirrors with a multi-layer reflectivity optical model based on the effective medium theory fed by the extracted physical parameters. In agreement with the experimental results, the model predicts a reflectivity of about 60 % for a sputtered aluminum thickness of 50 nm, compared to 97.5% reflectivity predicted by the bulk metal model. [2021-0154]

Using first principles calculations, we have presented a short study on modulation of band structures and electronic properties of zigzag blue phosphorene (ZbPNR) and arsenene nanoribbons (ZANR) by etching the edges of NRs. We have taken the width of both NRs as N = 8 and corrugated the edges in a cosine-like manner. Optimizing every structure and further investigating their stabilities, it was seen that both the etched NRs are energetically feasible. From the computed band structures, the band gaps were seen to be increased for both the NRs on increasing number of etched layers and direct gap semiconductor nature was recorded. Highest energy gap observed were 2.26 and 2.41 eV for ZbPNR and ZANR, respectively. On further application of electric field, we observed the very interesting semiconductor-to-metallic property transition which was explained by wave function plots. Being elements of same group, a similar trend of band gaps modulations was observed for both NRs. This fascinating method of electronic property tuning of the studied NRs can be useful in various nanoscale electronic applications.

The thermal atomic layer etching (ALE) of nickel was demonstrated using sequential chlorination and ligand-addition reactions. Nickel chlorination was achieved using SO2Cl2 (sulfuryl chloride) as t...

In this work, ZnO films are deposited by magnetron sputtering [using direct current (DC)], on polished silicon substrate Si(100) (non-etched), etched for 1 min, 5 min, 10 min and 15 min. The effect of etched silicon substrate on structural, morphological, and optical properties of ZnO films has been investigated. A new nanostructure can be obtained by mean of modification in morphology of substrate. The etching of the substrate was effectuated by means of dry plasma at different time and they compared with non-etched substrates. AFM and SEM images have been used to investigate the morphology behaviors of ZnO films growth on etched and non-etched silicon substrates. Optical properties were studied in details, photoluminescence (PL) showed that the intensity of ZnO films have been increased by increasing the substrate etching time from 0 to 15 min, which were associated with the crystallographic properties [for (002) orientation] using X-ray diffraction (XRD). That may be related to the decrease of grain size and roughness morphology increasing with the etching time. FTIR and MicroRaman spectra of films show vibrational modes characteristic of ZnO materials and they were related with morphology and structural of the films. In addition, the variation of ethylene glycol contact angle data (ECA) related to roughness of the ZnO films deposited on etched Si substrate at different times were studied. The ZnO films on etched substrate were interesting in optoelectronic purpose as well as for gas sensor in future work of our team.

International audience; Plasma etching techniques can result in damage and contamination of materials, which, if not removed, can interfere with further processing. Therefore, characterisation of the etched surface is necessary to understand the basic mechanisms involved in the etching process and enable process control and cleaning procedures to be developed. A detailed investigation by means of the combined use of scanning electron microscopy coupled with energy-dispersive X-ray spectrometry (SEM/EDS), X-ray photoelectron spectroscopy (XPS) and optical microscopy (OM) has been carried out on deep titanium trenches etched by plasma. This innovative approach has provided a further insight into the microchemical structure of the surface contamination layer on both the titanium and the nickel hard mask surfaces. The described experiments were conducted on 25 to 100-mu m wide trenches, first etched in bulk titanium by an optimised Cl-2/SF6/O-2-based inductively coupled plasma process, through an electroplated nickel hard mask. The results allow to identify chlorine, fluorine and carbon as the main contaminating agents of the nickel mask and to associate three oxidation states around the etched trenches highlighting certain specific aspects related to the passivation mechanism. These observations reinforce the scientific relevance of the combined use of complementary optical and imaging analytical techniques.

Metal-assisted chemical etching (MACE) of silicon is used in this study to fabricate silicon nanowire arrays (SiNWs) of different length. This method was modeled using gene expression programming (GEP), and GEP was optimized using genetic algorithms (GA). The length of SiNWs has been predicted as a function of parameters like Ag nucleation on Si and etching solution parameters. The SiNWs in the experimental test have a minimum length of 1 μm. According to FE-SEM images, SiNWs are uniformly shaped. It could be used to fabricate electrode materials for micro-supercapacitor.

As a layered photocatalyst, the photogenerated carriers separation efficiency of bismuth molybdate (Bi2MoO6) can be improved by introduction of oxygen vacancy. The alkali etching method provides a facile structural tuning way for modifying the bismuth-based semiconductors. Defect state bismuth molybdate (Bi2MoO6) photocatalyst was synthesized by alkali etching. The structure of Bi2MoO6 was tuned by adjusting the concentration of alkali solution. The phase structure, morphology, surface chemistry, and optical property of Bi2MoO6 were characterized by kinds of characterization methods such as X-ray diffraction, scanning electron microscope, X-ray photoelectron spectroscopy, UV–vis diffuse reflectance absorption spectroscopy. The phase of Bi2MoO6 can be transformed to Bi2O3 accompanied with the change of morphology due to the etching of molybdenum atom and oxygen atom from the Bi2MoO6 body structure by sodium hydroxide solution. Meanwhile, the concentration of oxygen vacancy increased obviously as indicated by the XPS results. Therefore, the separation efficiency of photogenerated carriers was enhanced because of the promotion of oxygen vacancy. Alkali etching Bi2MoO6 by 0.075 M sodium hydroxide solution exhibited an excellent photocatalytic performance owing to the suitable vacancy concentration. Superoxide free radicals instead of hydroxyl radicals took the important role in the photodegradation process.

Etching pores in the basal plane of graphene by wet-chemical methods with a certain size-control reflects a synthetic challenge. Here, a facile and controllable method is presented to produce solution-processible porous-graphene derivatives. The derivative of graphene oxide, here oxo-functionalized graphene (oxo-G) with a controlled density of in-plane vacancy defects is chosen as a precursor. Hydroxyl radicals are generated, which etch pores into the basal plane of oxo-G, preferably starting at defect sites. Thereby, solution-processible flakes of oxo-G with μm-size lateral dimensions and pores with tunable diameters between 5 nm and 500 nm are accessible. Moreover, a plausible mechanism for the growth of pores is proposed based on AFM, TEM, UV–vis spectroscopy, FTIR spectroscopy, XPS, solid-state NMR spectroscopy and statistical Raman spectroscopy. In first approximation, the electrophilic addition and oxidation reaction between hydroxyl radicals and oxo-G close to defect-sites is the basis for etching. The porous graphene materials may act as membranes or tunable two-dimensional materials.

Statement of problem Optimal composite resin bonds to polymer-infiltrated ceramic network (PICN) computer-aided design and computer-aided manufacturing (CAD-CAM) materials are essential for clinical success. However, comparative bond strength studies on the influence of different etching and cleaning methods on these materials are lacking. Purpose The purpose of this in vitro study was to measure and compare the microshear bond strength (μSBS) of a composite resin cement with that of a PICN material after different surface treatment and cleaning methods. Material and methods Seventy specimens of a CAD-CAM PICN were divided into 7 groups (n=10): no treatment (control), hydrofluoric acid etching for 20 seconds (HF20), 60 seconds (HF60), 120 seconds (HF120), HF20 + phosphoric acid for 60 seconds and ultrasonic bath for 5 minutes, HF60 + PH, and HF120 + PH. After surface treatment, a silane coupling agent and composite resin cement were applied. Microshear bond strength was determined, and data were analyzed with 1-way ANOVA and Tukey post hoc multiple comparison tests (α=.05). Results All HF acid treatments resulted in a significant increase in bond strength to the polymer-infiltrated ceramic network material (P=.02). Bond strength values for HF etching for 20 seconds were significantly lower than those for 60 seconds and 120 seconds (P=.034). No difference was found between 60 seconds and 120 seconds of HF etching time (P=.986). Additional surface treatment with phosphoric acid 60 seconds and ultrasonic bath 5 minutes did not improve the bond strength beyond values obtained by hydrofluoric acid treatment only (P=.834). Most failures were cohesive. Conclusions Acid etching and surface treatment have significant effects on composite resin bond strength to a PICN CAD-CAM material. HF etching for 60 seconds or 120 seconds provides the highest bond strengths. Cleaning methods after etching did not have any significant effect on bond strength.

MXene (Ti3C2Tx) is a novel, two-dimensional (2D) layered material that is atomically thin, exhibits good mechanical strength, and is ideal for fabricating efficient membranes for molecular separation. However, the applications of MXene membranes are limited by their low water permeability owing to narrow channels and high tortuosity. A novel strategy for introducing artificial pores on the surface of MXene nanosheets via gentle in situ chemical etching with hydrogen peroxide (H2O2) to prepare porous MXene nanosheets (PMS) is reported herein. This greatly increases the water permeability of MXene membranes while retaining the high rejection of small-molecule dyes. Permeable pores generated on MXene nanosheets transform the transport model of water molecules in the membrane from typical horizontal transport pathways dominated by interlayer channels to longitudinal–lateral three-dimensional transport pathways, affording increased water molecule transport channels and reduced transport distance. Based on different etching conditions, the obtained membranes exhibit high pure-water permeability ranging from 9.37 to 42.48 L m−2 h−1 bar−1. Moreover, mild etching maintains the 2D structure of the membrane and retains a nearly complete rejection of congo red dye. This study provides a novel and effective strategy for preparing high-performance porous laminar MXene membranes for dye-separation applications.

Diamond and graphene are carbon allotropes with starkly different physical characteristics. Their combination into graphene-on-diamond heterostructures could benefit from the complementary properties of both components. Graphitization of single-crystalline diamond surfaces is a promising synthesis route, but a clear understanding of the growth of graphene or graphite from solid carbon sources is so far missing. Using aberration-corrected transmission electron microscopy, Raman spectroscopy, and electrical transport measurements, we provide detailed insight in the mechanisms of structural changes of nickel-catalyzed graphitization of diamond. We propose competing atomistic processes occurring at contact sites of diamond and Ni, depending on diamond surface terminations. One-dimensional etching process dominates on (111) diamond surfaces that remain almost atomically flat during graphitization. Two-dimensional etching of (110) and (100) diamond surfaces results in Ni drilling into the diamond substrate. Our findings also provide evidence on the reaction rates of the catalysis. The most reactive diamond surface in the (100) orientation is covered with the largest amount of well-crystallized graphite, whereas the (111) surface shows the highest stability against catalytic etching. In the latter case, only a thin disordered graphite layer is formed, yielding the lowest electric conductance. By clarifying these etching mechanisms, our results can improve the synthesis of graphene-on-diamond heterostructures.

Potassium-ion batteries (KIBs) have become the most promising alternative to lithium-ion batteries for large-scale energy storage system due to their abundance and low cost. However, previous reports focused on the intercalation-type cathode materials usually showed an inferior capacity, together with a poor cyclic life caused by the repetitive intercalation of large-size K-ions, which hinders their practical application. Here, we combine the strategies of carbon coating, template etching and hydrothermal selenization to prepare yolk-shelled FeSe2@N-doped carbon nanoboxes (FeSe2@C NBs), where the inner highly-crystalline FeSe2 clusters are completely surrounded by the self-supported carbon shell. The integrated and highly conductive carbon shell not only provides a fast electron/ion diffusion channel, but also prevents the agglomeration of FeSe2 clusters. When evaluated as a conversion-type cathode material for KIBs, the FeSe2@C NBs electrode delivers a relatively high specific capacity of 257 mAh/g at 100 mA/g and potential platform of about 1.6 V, which endow a high energy density of about 411 Wh/kg. Most importantly, by designing a robust host with large internal void space to accommodate the volumetric variation of the inner FeSe2 clusters, the battery based on FeSe2@C NBs exhibits ultra-long cycle stability. Specifically, even after 700 cycles at 100 mA/g, a capacity of 221 mAh/g along with an average fading rate of only 0.02% can be retained, which achieves the optimal balance of high specific capacity and long-cycle stability.

Electrochemical machining (ECM) is a promising method to generate microgrooves in difficult-to-cut materials. This paper utilizes a tungsten arrayed microtool to fabricate microgrooves on a flexible metallic foil via ECM. A pulsed current was employed for refreshing the electrolyte, and a mathematical model was built to explore which factors affect the inter-electrode side and bottom gaps. It implies that several factors such as the pulse-related parameters, microtool size and feed rate, indeed, influence the microgroove dimensions and profiles. Experiments indicated that as the pulse duty cycle and pulse period increased, the effective machining time for the microgrooves was prolonged, thereby increasing both the width and depth of microgroove. Thus, a pulsed current with a small pulse duty cycle and a short pulse period was useful for improving the machining quality of the microgrooves. Moreover, the microgroove dimensions were inversely proportional to the spindle speed due to the higher feed rate. However, the trends of change in the width and depth of the microgrooves were similar as the spindle speed increased, which led to a slight change in the localized etching ratio. For a thicker arrayed microtool, the effective machining time increased, the electrolyte flow path was longer, and the flow field at the machining gap became worse, thereby deteriorating the dimensional consistency and profiles of the microgrooves. Accordingly, the machining quality of microgrooves for a tool electrode thickness of 0.50 mm were considerably better than for a thickness of 1.00 mm.

The geometrical dependence of humidity sensors on sensing performance has not been quantitatively outlined. Furthermore, the etching effect on humidity sensors is still elusive due to the difficulty in separating the effects of the geometrical change and etching-induced porosity on the overall performance. Here, we use COMSOL Multiphysics to perform a numerical study of a capacitive graphene oxide (GO) humidity sensor, with emphasis on the dimensions and etching effect on their sensing performance. GO is a useful and promising material in detecting humidity because of its selective superpermeability to water molecules. The mechanism of improved sensing performance of the etched humidity sensors is discussed in terms of the morphological profile and the effective permittivity including the etching-induced porosity effect. Our study shows that as compared to the unetched sensors, isotropic etching achieves the lowest response time of 1.011 s at 15.75% porosity, while vertical etching achieves the highest capacitance sensitivity of 0.106 fF/RH %.

Herein, titanium dioxide (TiO2)-coated vertically aligned silicon nanowires (SiNWs/TiO2) were fabricated and evaluated for photocatalytic degradation of organic dyes. Aligned SiNWs arrays were prepared by facile metal-assisted chemical-etching process with varying the etching time that was followed by TiO2 nanoparticles coating using sputtering technique. The TiO2 film crystallized in pure anatase phase with an average crystalline size of 50 nm, as was elucidated with X-ray diffraction studies. SEM analysis showed nanowires with varying lengths from 2.5 to 13.5 µm and confirmed the homogenous surface decoration with TiO2. The homogeneous distribution of TiO2 nanoparticles on nanowires was co-evidenced with Energy-Dispersive X-ray spectroscopy (EDX) and Raman spectra analysis. The developed SiNWs/TiO2 was exploited for photocatalytic degradation of methylene blue; the role of hydrogen peroxide was also elucidated. The highest photocatalytic efficiency of 96% was achieved for SiNWs/TiO2 with optimum nanowire length of 3.5 μm. The developed photocatalyst was found to be almost stable even after 190 days (~ 5 months) and could be used as reusable and easily removable photocatalysts. The current study highlighted the SiNWs/TiO2/H2O2 system as excellent candidate for water remediation applications.

This work demonstrates the high-performance hydrogen peroxide (H2O2) sensing field-effect transistor (FET) using reduced graphene oxide - polypyrrole (rGO/PPy) nanocomposites. The SiO2 trench type FET is fabricated using lithography and etching techniques. The fabricated SiO2 trench structure was used not only for holding H2O2 but also for sensing purpose. The morphology and structure of the rGO/PPy nanocomposites were analyzed and confirmed their bonding. The output electrical signal changes as the concentration of H2O2 increases. The device shows a fast response of 5 s and is highly stable with excellent sensitivity. The detection limit obtained is 10 pM at appropriate signal-to-noise ratio (S/N) of the sensing electrical signal. The device is high selectivity towards H2O2. The device structure may be employed for other liquid sensing applications.

For achieving the fine pitch chip-on-film (COF) in display devices, wet chemical spray etching behaviors of the copper (Cu) films in the etching solutions with different cupric chloride (CuCl2) and...

Preparation of edge-rich two-dimensional (2D) transition metal dichalocogenides (TMDs) has been actively investigated with the aim to improve their electrical and catalytic properties. Here, we elucidate the role of potassium ions in oxidation of TMDs and suggest a consequent novel anisotropic etching mechanism driven by self-running oxide droplets. We discover that potassium-mediated oxidation of MoS2 leads to the formation of K-intercalated hexagonal-phase molybdenum oxides (h-KxMoO3), whereas orthorhombic-phase oxides are formed in the absence of potassium ions. Metastable h-KxMoO3 appears to have decomposed into oxide droplets at higher temperature. Self-running of the oxide droplets leads to layer-by-layer anisotropic etching of MoS2 along the armchair direction. The motion of the droplets appears to be triggered by the surface energy instability between the oxide droplets and the underlying MoS2 layer. This study opens new possibilities to design and manufacture novel edge-rich 2D TMDs that do not follow the equilibrium Wulff shape by modulating their oxidation with the assistance of alkali metals and also offers fundamental insights into the interactions between nanodroplets and 2D materials toward edge engineering.

Miniaturization of electronic devices down to the nanoscale needs corresponding processing technologies with precision at the atomic layer level. The plasma atomic layer etching (ALE) technique is playing an active role in this demand. However, theoretical research on the ALE mechanism is a great challenge. We propose a method of spontaneously searching adsorption sites (SSASs) to understand what surface chemistry occurs in the ALE processing of MoS2 treated by the remote oxygen plasma. The SSAS results are in good agreement with experimental observations. Chemical adsorption of O atoms occurs only in the topmost layer of the MoS2 surface. The MoS2 surface has four different adsorption sites with different probabilities of binding an O atom, denoted by 0Sbb, 0Sbbc, 2Sbb, and 3Sbb configurations, which have zero, zero, two, and three S-Mo bonds broken by the introduced O atom, respectively. Four adsorption sites of the MoS2 surface play different roles in the surface oxidation in the remote oxygen plasma.

We introduce a new innovative damage-free neutral beam etching (NBE) technique to transfer a honeycomb resist pattern to silicon (Si) wafer (thickness of 180 µm). Front-surface texturing of Si helps to reduce surface reflection and increase light absorption for solar cell applications. NBE was performed with Cl2 and Cl2/ SF6 gases chemistries, and the influence of the etching time on the etching profiles, surface reflection and potential short-circuit densities (p-JSC) was studied. The Si etching rate with pure Cl2 was ~ 5 nm/min and resulted in anisotropic etch profiles and a minimum surface reflection of 15% at 1000 nm, which is too high for practical use. With the introduction of 5% of SF6, the etching rate increased to 30 nm/min, the etching became isotropic (anisotropy of ~ 1), and sloped sidewalls appeared. NBE with Cl2 (95%)/SF6 (5%) produced a sample with an average surface reflection of 3.7% over the wavelength range 300–1000 nm without any antireflection coating. The minimum surface reflection in this case was ~ 1% at 1030 nm and p-JSC was 40.63 mA/cm2. This type of surface pattern is well suited for low-consumption-material (thin), high-efficiency Si solar cells.

The corrosion behavior of ferritic (Fe-11Cr) and austenitic (Fe-18Cr) steels has been investigated in static liquid lead containing 5 × 10–7 wt.% oxygen at 550°C and exposure up to 1000 h. It was determined that corrosion damage of surface layers occurs along grain boundaries. This is accompanied by etching of grain boundaries and penetration of liquid lead into the matrix, with simultaneous dissolution of the main alloying elements (Ni, Cr, and Mn) of the steels. It was established that the applied loads accelerated the corrosion processes in the contact of the steels with liquid lead. The austenitic steel showed better corossion resistance under loads than did the ferritic steel.

This paper presents a lead zirconate titanate (PZT) thick-film microcantilever fabricated on a stainless-steel substrate using electrohydrodynamic jet (E-jet) deposition. PZT thick-film functional layer arrays were produced directly on stainless-steel substrates via E-jet deposition to form microcantilevers with a width of only 150 μm and thickness of 62 μm. The method can realise batch manufacturing of microscale cantilevers, improve the PZT active layer energy and microcantilever fracture toughness under vibrational deformation, and eliminate the need for complex photolithography and etching processes. The microcantilever accurately realised the correct mode shapes, consistent with simulation results. The vibrational amplitude of the microcantilever reached 5.14 μm, while Qm was up to 688.1, considerably larger than those of thick-film silicon-based microcantilevers and free-standing microcantilevers with similar sizes. An effective electromechanical coupling coefficient, Keff, of approximately 0.13 was obtained. The potential for efficient applications in microelectromechanical system piezoelectric devices was confirmed.

Titanium nitride (TiN) is widely used in electrode materials in fast charging/discharging supercapacitors (SCs) due to its outstanding conductivity. However, the low capacitance of the TiN electrode limits its further application in the SCs. Therefore, the reasonable design of the TiN electrode with high electrochemical and mechanical properties is still a challenge. In this paper, the silicon nanowires/titanium nitride electrode (Si NWs/TiN) is prepared by depositing TiN onto the etched Si nanowires by direct current magnetron sputtering. The Si NWs are prepared by etching silicon in 4.8 M HF/0.02 M AgNO3 aqueous solution for different times (5 min, 15 min, 30 min, 60 min). The mechanism of the effect of etched silicon substrate morphology on the electrochemical performance of Si NWs/TiN electrode was studied. As the etching time increases, the differences of the TiN surface structure, lattice defects and surface chemical composition will change the capacitance performance and charge storage mechanism of the Si NWs/TiN electrode. The prepared Si30 NWs/TiN electrode exhibits an outstanding specific capacitance as high as 113.55 F g−1 at a scan rate of 5 mV s−1 with 0.5 M H2SO4 solution as electrolyte. The specific capacitance of the Si30 NWs/TiN electrode is as high as 7.5 times that of the electrode without etching at 100 mV s−1. The Si30 NWs/TiN electrode has an excellent cyclic stability performance, which the electrode has a decay rate of 12.4% after 2000 cycles. This indicates that the electrode has reliable stability. The electrode of the supercapacitor prepared by this method can open up a new way to expand the specific surface area of other transition metal nitride.

This paper reviews materials challenges and recent progress for selective area regrowth and doping for vertical gallium nitride (GaN) power devices. The purpose is to realize randomly placed, reliable, contactable, and generally useable laterally patterned p-n junctions, which are the building blocks for various advanced power rectifiers and transistors. The general regrowth process and regrowth dynamics in trenches were discussed, where the effects of trench geometries, growth methods, and bulk substrates were elucidated. Comprehensive materials characterization techniques were utilized to analyze the regrown structures, including scanning electron microscopy, transmission electron microscopy, atom probe tomography, scanning probe microscopy, and secondary-ion mass spectrometry. Cathodoluminescence and secondary electrons in scanning electron microscopy and atom probe tomography were used to achieve lateral and vertical dopant profiling at a sub-micron scale. The regrowth interface after dry etching accumulated a high density of impurities and charges, contributing to the formation of a p+-n+ tunneling junction. This hypothesis was further confirmed by the electrostatic potential profile at the regrowth interface using electron holography. Novel etching technologies were investigated to improve the regrowth interface. It was found that low-power dry etching significantly reduced the interfacial charges and the reverse leakage currents of regrown p-n junctions. Photoelectrochemical wet etching was found to be effective in reducing deep-level defects near the regrowth interface. Atomic layer etching uses self-limiting chemical processes, thus removing the damaged layers without inducing further etching damage. Tertiarybutylchloride-based in situ etching may serve as an alternative etching method to dry etching with reduced etching damage. In terms of devices, regrown p-n junctions with low leakage currents and vertical junction field-effect transistors were demonstrated. Further improvements in selective area regrowth and associated devices can be expected using regrowth optimization and regrowth interface engineering via surface treatments and low-damage etching. These results represent an important step towards realizing selective area regrowth and doping for high performance GaN power electronics devices and systems.

Strong absorption, thin thickness, low density and broad band are ideal characteristics of electromagnetic wave absorption (EWA) materials. In this work, ultralight porous carbon hollow nanoboxes (PCHN), which have low density and high specific surface area, are successfully prepared by the vapor deposition and etching process. Excellent EWA performances are achieved in the filler with only 3 wt%. A minimum reflection loss (RLmin)value of −30.46 dB (2.2 mm) along with an efficient absorption bandwidth (EAB) (RL ≤ −10 dB) of 5.44 GHz is achieved. And the EAB (RL ≤ −20 dB, corresponding to 99% absorption) can be tuned in the frequency band of 4.88–17.04 GHz via adjusting the thickness from 6.0 to 1.9 mm. The excellent EWA performance is attributed to conduction loss, interfacial polarization, and good impedance matching. Moreover, the adjacent carbon micro-sheets can provide multiple positions for EW reflection, which prolongs the propagation paths of EW and is conducive to the consumption of EW energy. The light weight, broad band and superior RLmin value make the as-prepared PCHN promising candidates for practical EWA applications.

A single-crystal islands (SCI) technique using low thermal budget pulse laser process is proposed and demonstrated to fabricate single-crystal silicon islands over amorphous dielectric for monolithic 3-D and back-end-of-line (BEOL) FinFET circuits. By laser recrystallizing mask-defined a-Si islands encapsulated with conformal silicon nitride film, designed single-crystal Si islands can be obtained. The single crystallinity of the island are verified with SECCO Etch, high-resolution electron microscopy (HREM), transmission electron microscopy (TEM), and electron backside scattering (EBSD). About 40 nm FinFETs were successfully fabricated in the SCI Si islands and shown to exhibit excellent electrical performance and low variability that are compatible with the FinFETs fabricated on commercial silicon-on-insulator (SOI) wafer.

In the dry etching of borosilicate glass (BSG), the process gas reacts with the impurities of borosilicate glass and forms a non-volatile compound layer on the surface. This surface compound layer (SCL) makes it difficult to control the surface morphology and device structure dimension with precision and significantly influences the etch rate. We examined the influence of SCL on the etch rate of quartz and BSG and discussed its etching mechanism depending on the thickness of the SCL. The formation of SCL was dominated by both the plasma gas composition and substrate material, and the etching regime can be defined by the thickness of the SCL. A thin SCL was formed on the BSG by CF4/Ar gas plasma etching, and the etch rate was suppressed by the SCL. A significantly thin SCL was formed on the quartz specimens under in same etching conditions, and a direct etching reaction was occurred. As the ratio of physical etching gas (Ar) increased, both the ion energy flux and the physical ion bombardment increased and consequently improved the etch rate. The SCL plays the role of an F radical supplier, while the thick SCL reduces the etch rate because it takes time for the etchants to transit from the surface to the interface. The SCL acts as a barrier in the etching reaction, which could be adjusted by the regulation of the etching gas composition or the plasma parameters, such as the inductive power and the bias power of the RIE reactor. [2021-0071]

Efficient utilization for synergistic effect from different electrode materials with optimized structure and composition is a promising strategy to enhance electrochemical performance of composite electrodes. In this work, amorphous ball-flower-like NiO loaded on N, S-doped silicon oxycarbide-drived carbon (NSCDC/NiO) composites with tunable microstructure were synthesized through an easy alkali etching method followed via a hydrothermal method. The synthesized NSCDC/NiO electrodes display a good capacitance (804 F g−1/111.7 mAh g−1 at 1 A g−1) and hopeful cyclic property. Furthermore, the asymmetric supercapacitor (ASC) device assembled using NSCDC/NiO as anode and N, S-doped silicon oxycarbide-drived carbon (NSCDC) as cathode possesses excellent energy density (100.6 Wh kg−1) when the power density reaches 850.2 W kg−1. After 5000 cycles, ASC device has 84.0% retention rate of original capacitance, showing that the NSCDC/NiO composite is a satisfying and promising electrode applied in supercapacitors. The electrochemical properties of NSCDC/NiO composites are greatly improved owing to the excellent electrical conductivity of NSCDC framework, ball-flower-like NiO with amorphous state and hierarchical porous structure, which are beneficial to transportation of ion and electron, reduction of volume change during charge-discharge process.