Hybrid Surface Research Articles

Prediction of Cr(VI) and As(V) adsorption on goethite using hybrid surface complexation-machine learning model

This study aimed to develop surface complexation modeling-machine learning (SCM-ML) hybrid model for chromate and arsenate adsorption on goethite. The feasibility of two SCM-ML hybrid modeling approaches was investigated. Firstly, we attempted to utilize ML algorithms and establish the parameter model, to link factors influencing the adsorption amount of oxyanions with optimized surface complexation constants. However, the results revealed the optimized chromate or arsenate surface complexation constants might fall into local extrema, making it unable to establish a reasonable mapping relationship between adsorption conditions and surface complexation constants by ML algorithms. In contrast, species-informed models were successfully obtained, by incorporating the surface species information calculated from the unoptimized SCM with the adsorption condition as input features. Compared with the optimized SCM, the species-informed model could make more accurate predictions on pH edges, isotherms, and kinetic data for various input conditions (for chromate: root mean square error (RMSE) on test set = 5.90 %; for arsenate: RMSE on test set = 4.84 %). Furthermore, the utilization of the interpretable formula based on Local Interpretable Model-Agnostic Explanations (LIME) enabled the species-informed model to provide surface species information like SCM. The species-informed SCM-ML hybrid modeling method proposed in this study has great practicality and application potential, and is expected to become a new paradigm in surface adsorption model.

Concentric interdigitated dielectrodes on silica substrate to monitor neuroprotective effect of anesthetics

General anesthesia is commonly used in major surgeries, in most cases it is completely reversible and central nerve system returns normal after the elimination of anesthetic agent. At the same time, usage of anesthetic agents may result in a long-lasting neurological effect due to increasing level of neural injury biomarker. Various neuro-proteins have been identified to provide a clear insight of neurological injury, among them, tau protein level fluctuates during the pre- and post-operative periods, which leads to different neurological complications, such as Parkinson’s and Alzheimer’s diseases. This research was focused to develop a sensitive tau protein biosensor on modified concentric interdigitated dielectrode surface and measured by impedance spectroscopy. The sensing surface with silica substrate and embedded gold dielectrodes were used for aptamer-antibody sandwich assay and attained the detection limit of tau protein to 1 fM on a linear regression range until 1 nM (R2 = 0.9899; y = 535.04x −398). Further, selective experiments in tau protein spiked artificial cerebrospinal fluid increases the current responses with the concomitant increment of tau protein. Experiments with complementary aptamer, amyloid-β40 and recombinant human complement failed to response. This tau biosensor helps to quantify tau protein levels silica-gold hybrid surface and monitor the neuroprotective effect of anesthetics.

Production of AA6061/TiB2/B4C/GNP hybrid surface composites processed by friction stir processing (FSP) and ınvestigation of mechanical properties

Bu çalışmada sürtünme karıştırma yöntemi ile AA6061 alüminyum alaşımı ve farklı oranlarda TiB2/Nano Grafen/B4C takviyeli hibrit yüzey kompozitleri üretilmiş ve mekanik özellikleri ile mikroyapı analizleri yapılmıştır. AA6061 altlığı üzerine 2 mm sabit aralıklarla 3 mm çapında ve 1.5 mm derinliğinde delikler açılmış, açılan bu deliklere farklı oranlarda karıştırılmış TiB2/Nano Grafen/B4C tozları doldurulmuştur. Takviye tozları ultrasonik ve mekanik olarak karıştırılmıştır. Sürtünme Karıştırma yöntemi ile 7 farklı takviye oranında hibrit yüzey kompoziti aynı profilde karıştırıcı uç kullanılarak sabit hızda üretilmiştir. Üretilen kompozitlerin çekme dayanımları, farklı yüklerdeki aşınma dirençleri ve sertlikleri belirlenmiştir. Ayrıca optik ve SEM mikroskoplar ile mikroyapı, kırık yüzey ve aşınma yüzeyi analizleri ile element haritalaması yapılmıştır. En düşük çekme dayanımı takviyesiz alaşımda elde edilirken TiB2, nano grafen ve B4C ilaveli yüzey kompozitlerin dayanımı artmıştır. Mikroyapılarda herhangi bir gözenek ve boşluk tespit edilmemiştir Kırık yüzeylerde takviye elemanı arttıkça gevrek kırılmaların meydana geldiği görülmüştür.

Survival analysis of dental implants placed in horizontally severely resorbed maxillae after reconstruction with xenogeneic graft: a case series.

To evaluate the survival rates of dental implants with a hybrid macrostructure and the surface biomimetically coated with nanohydroxyapatite, placed in horizontally atrophic maxillae previously submitted to the guided bone regeneration (GBR) procedure, associated with the use of a deproteinized bovine bone graft (DBB). Twenty-five patients who received 196 implants were involved in this study. First, these patients were submitted to GBR procedures and maxillary sinus lift, where DBB was used as the grafting material. The dental implants were placed after a minimum period of 6 months of the grafting procedures. The patients were followed up every six months and clinical/radiographic examinations were performed to assess the implants, using the following indicators as a reference: (1) Absence of mobility; (2) Absence of pain. Data about the age, surgery time, smoking status, implant size, and time between the grafting procedure and implant placement were correlated with implant failures. Twelve implants failed, generating a survival rate of 94.23%. None of the variables analysed correlated with the implant failures. Implants with a hybrid macrostructure and surface biomimetically coated with nanohydroxyapatite present good survival rates in horizontally atrophic maxillae grafted with DBB.

Comparative analysis of reinforcement addition techniques on fabricated hybrid surface composite of AA7075-T651/WC/BN through friction stir processing

In the present work, three reinforcement addition techniques such as the slot method (SM), hole method (HM), and zig-zag hole method (ZZHM), are selected to make the hybrid surface composite of AA7075-T651/BN/WC through FSP. The comparative assessment of each method is thoroughly assessed through microstructure, mechanical, and tribological characteristics. Material flow, particle spreading, zone development and phase formation were examined using optical microscopy (OM), field emission scanning electron microscopy (FESEM) with energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). Furthermore, the microhardness and wear characteristics were measured and compared. Based on the findings, ZZHM reveals enhanced material flow and more even particle spreading in the nugget zone than SM and HM. The higher grain refinement and excellent interfacial bonding without any reaction between AA7075-T651 and reinforcement particles (BN and WC) are due to higher DRX and severe plastic deformation (SPD) caused by the tool in ZZHM. The composite made with ZZHM had greater hardness and wear resistance due to the reduction in clusters, even the spreading and lubricating effect of particles and a significant reduction in grain size. This study revealed that the ZZHM is superior to the SM and HM for adding reinforcement and fabricating the hybrid surface composite.

Green synthesis of hybrids of zinc oxide, titanium oxide, and calcium oxide nanoparticles from Foeniculum vulgare: an assessment of biological activity

The increased prominence in the use of nanoparticles has made it important to employ synergy between nanoparticles while harnessing individual metallic and biological properties to improve and modify the surface, the versatility, and efficiency of nanoparticle hybrid. This study aims to conduct a bio-assessment assay of nanoparticle hybrid systems within an in-vitro set-up and improve the surface modifications of these systems. The hybrid surfaces are characterized using a scanning electron microscope, dynamic light scattering (DLS), X-ray diffraction analysis (XRD), and Fourier-transform infrared spectroscopy (FTIR). FTIR reveals the presence of functional groups like phenols, carboxylic acids, and esters. The XRD confirms the hexagonal crystalline phase of Fe-NZnO, the cubic lattice of Fe-NCaO, and the rutile phase of TiO2. The hydrodynamic diameter of Fe-NZnO-NCaO, Fe-NTiO2-NCaO, and Fe-NTiO2-NZnO are shown to be 163.2, 164.6, and 219.4 nm, respectively, using DLS analysis. Turbidity analysis indicates that Fe-NZnO-NCaO is the least aggregated particle following a 14-day observation period, meaning that it is the most stable over that period. Anti-hemolytic erythrocyte assay demonstrates the relative biocompatibility and ability of the hybrids to enhance cell protein protection. Fe-NZnO-NCaO and Fe-NTiO2-NCaO exhibit higher post-treatment cytotoxicity across the concentrations than Fe-NTiO2-NZnO.

Enhancing the reliability of laser welded-brazed aluminum/stainless steel joints via laser-chemical hybrid surface texturing

Surface microtexture is a promising technique for enhancing the quality of heterogeneous joints. This study developed a novel surface texturing method to improve the reliability of laser welded-brazed aluminum/stainless steel joints. The method combined laser etching and chemical etching to create high-quality multi-scale surfaces with large grooves and small wrinkles. The designed microtexture promoted atomic transfer and induced the generation of nanoscale η-Fe2(Al,Si)5 phases during the welding-brazing process. It reduced the spreading activation energy along the groove direction, which enlarged the joining area. It also optimized the strain-stress distribution to enhance the deformation tolerance of the bonding interface throughout the structural strengthening mechanism. Through the synergistic regulation, the joint achieved a maximum line load of 495.9 N/mm, which was 61 % higher than the untextured joint of 307.5 N/mm. The joint performance reached 95 % of the Al/Al lap joint (519.3 N/mm) with the same welding parameters. This study provided new insights into the high-quality joining of aluminum/steel systems or other heterogeneous materials.

Design and study of a new QPQ combined with ultrasonic roller pressing method for gear surface strengthening

This study investigates a hybrid surface enhancement technique that combines Quench Polish Quench (QPQ) with ultrasonic rolling to augment the durability of 42CrMo gears against wear and fatigue. Analysis reveals that post-treatment, the composite nitride layer on the gear surface maintains its original phase composition, evidenced by the absence of new diffraction peaks in X-ray diffraction (XRD) patterns. Nevertheless, a noticeable broadening in these peaks suggests grain refinement and the presence of microstrain due to the rolling process. Incremental static pressures improve the mechanical characteristics of the surface, with the layer treated at 0.6 MPa exhibiting the lowest wear rate (3.15 × 10−8 mm3N−1 m−1). Oxidative wear increases at elevated temperatures (100 °C), yet under lubricated conditions, Coefficient Of Friction (COF) of the treated layer significantly reduces. The predominant wear mechanisms include mild abrasive wear, oxidative wear, and adhesion. Excessive impact force, particularly at 0.6 MPa, risks surface cracking and subsequent degradation in fatigue resistance. Optimal fatigue performance is achieved with a static pressure of 0.4 MPa, corresponding to a surface strength of 2300 MPa and a fatigue life of 3.23 × 106 cycles.

Effect of Surface Renewal on the Drop Size Distribution in Dropwise Condensation within a Hybrid Surface

The description of liquid drop growth and drop distribution are two key models in evaluating the thermal performance of dropwise condensation (DWC) heat transfer. The drop size distribution describes the growth process of small drops by direct condensation and large drops by coalescence. The present work investigates the effect of surface renewal and coalescence intensities of DWC within a hybrid surface. Additionally, it examines the validity of the current empirical expression of the drop size distribution that is developed for DWC without considering surface renewal and coalescence intensities. The simulation work illustrates the drop growth process and surface renewal as drops depart and merge with neighboring film regions. The simulation results show that in hybrid DWC, the area fraction occupied by drops (f) lies between 0.28 to 0.296 for the ratio of maximum drop diameter to DWC region width (RD) from 0.125 to 1 and a total temperature drop (∆T) of 2, 4, and 8 ℃. Thus, the drop population is less sensitive to RD, and an average f of 0.288 is generalized. On the other hand, the surface renewal for DWC within the hybrid surface shows improvement for RD > 0.5 with the highest enhancement of 64 to 85% taking place at RD = 1, mainly due to the merging effect. In addition, results for drop size distribution profiles of DWC within the hybrid surface are characterized by a lower population of large drops and a higher population of small drops than full DWC. Additionally, the constant exponent (n) in the literature’s empirical expression is replaced by a polynomial series as a function of drop effective and maximum radii. The impact of surface renewal on coalescence intensity is presented in a relatively steeper slope on the logarithmic scale.

A hybrid surface shape control method for optimizing thermal deformation of FEL reflection mirror

The surface shape errors induced by thermal deformation of the free electron lasers (FEL) beamline reflection mirror directly affect the quality of FEL beam. In order to reduce the thermal deformation and meet the stringent requirements of surface shape error of the FEL reflection mirror, this paper proposes a surface shape control method that combines mirror bending and active thermal control (ATC) technique, aiming to minimize surface shape errors and enhance the overall performance of the FEL beamline. A bending mechanism has been designed to achieve a bending sensitivity of 60 nrad RMS/N using only one bending actuator. It does not obstruct the FEL beam with extremely small incident angle. This mechanism can compensate for thermal deformation by eliminating the cylindrical surface component of the thermal deformation. Additionally, a novel ATC algorithm is proposed based on the Tikhonov regularization method. When combined with the bending mechanism, it proves effective in controlling the surface shape of the reflection mirror. The simulation results indicate that this surface control method can effectively reduce the surface shape errors of the reflection mirror. Taking the 3 nm wavelength FEL as an example, the RMS value of surface slope error of the reflection mirror is substantially reduced from 17.1974 μrad (with heat load) to 0.0913 μrad after bending. Based on the bending result, the ATC technique further reduces the slope error to 0.0303 μrad RMS. For 1 nm and 2 nm wavelength FELs, the mirror slope errors ultimately reach 0.0147 μrad RMS and 0.0295 μrad RMS respectively. This surface shape control method ensures that the reflection mirror slope errors meet the beamline requirement, which is 0.05 μrad RMS, thereby guaranteeing the beam quality.

Comparative Analysis of Shape Defects Induced by the Micro-Machining of Glassy Polymers

Abstract This paper aims to investigate the cutting behavior of optical glassy polymers in order to identify the shape defects induced by the micro-machining processes. Polycarbonate (PC), Allyl Diglycol Carbonate (CR39), and polythiourethane (MR7) polymers are considered in this study to perform micro-machining experiments using the orthogonal cutting configuration. The comparative analysis is carried out by conducting the cutting experiments on hybrid samples that are composed of two types of polymers (MR7-PC, CR39-PC, and MR7-CR39) and then comparing the topographic state of the machined hybrid surfaces. Results show that PC is by far the polymer that generates the most shape defects because of its high rate of spring-back. This finding has been validated by nanoindentation experiments that reveal the highest mechanical reaction of PC at the time of nanoindentation unloading. This study demonstrates also that the measured thrust forces could be an indicator for predicting the spring-back defects induced by micro-machining.

Defect engineering in transition‐metal (Fe, Co, and Ni)‐based electrocatalysts for water splitting

AbstractElectrocatalytic water splitting seems to be an efficient strategy to deal with increasingly serious environmental problems and energy crises but still suffers from the lack of stable and efficient electrocatalysts. Designing practical electrocatalysts by introducing defect engineering, such as hybrid structure, surface vacancies, functional modification, and structural distortions, is proven to be a dependable solution for fabricating electrocatalysts with high catalytic activities, robust stability, and good practicability. This review is an overview of some relevant reports about the effects of defect engineering on the electrocatalytic water splitting performance of electrocatalysts. In detail, the types of defects, the preparation and characterization methods, and catalytic performances of electrocatalysts are presented, emphasizing the effects of the introduced defects on the electronic structures of electrocatalysts and the optimization of the intermediates' adsorption energy throughout the review. Finally, the existing challenges and personal perspectives of possible strategies for enhancing the catalytic performances of electrocatalysts are proposed. An in‐depth understanding of the effects of defect engineering on the catalytic performance of electrocatalysts will light the way to design high‐efficiency electrocatalysts for water splitting and other possible applications.

A Long-Term Split-Mouth Randomized Controlled Trial to Assess Implant Treatment Outcome Using Implants with a Different Surface Roughness

The influence of implant surface roughness on implant treatment outcome is still under debate. A rougher implant surface improves osseointegration but yields greater plaque accumulation and biofilm formation. Hybrid implants have a minimally rough component coronally and a moderately rough implant body. The aim of this split-mouth study is to evaluate the long-term outcome of treatment with hybrid and moderately rough implants after 6 years. As a secondary aim, Oral Health Quality of Life (OHQoL) was assessed after one and six years. Fully edentulous patients received an overdenture supported by two implants. One implant had a hybrid surface (MSC) and one implant had a moderately rough surface (DCC). Radiographic crestal bone loss (CBL), plaque score, bleeding on probing (BoP) and periodontal probing depth (PPD) were determined at one and six years. OHQoL was evaluated using the Oral Health Impact Profile-14 (OHIP-14) questionnaire and a Visual Analogue Scale (VAS). Twenty-one patients with 42 implants were evaluated after 6 years. No implants failed and a mean CBL of 0.26 mm (SD: 0.42) for the MSC group and 0.17 mm (SD: 0.29) for the DCC group was observed, which was not statistically significant. Periodontal parameters were comparable after 6 years and a significant improvement in OHQoL was observed. This randomized controlled trial concludes that hybrid implants are a predictable treatment alternative for moderately rough implants in patients with an overdenture supported by two implants.

Magnetic Nanocomposites for Removal of Arsenic from Water

Arsenic significantly impacts human health and the environment and its removal from wastewater is still difficult. Magnetic nanoparticles have come to light as a viable arsenic remediation technique, providing a fresh and long-lasting water purification method. This study investigates the use of magnetic nanoparticles to remove arsenic by concentrating on their adsorption mechanism, kinetics, potential for adsorption, recovery, and promising use of this method in the future. Due to the extensive surface area and variable surface chemistry of magnetic nanoparticles, they can effectively adsorb arsenic from water sources. Because their magnetic properties simplify separation and regeneration, they may be used again with little to no efficiency loss. As a result, they reduce trash output by providing an ecologically acceptable alternative to traditional adsorbents. The present study also examines the kinetics and adsorption process of magnetic nanoparticles, emphasising their improved selectivity and capacity for adsorption. Due to these characteristics, the authors were able to successfully remove arsenic from wastewater, resulting in better water quality and decreased health hazards after exposure to arsenic. Additionally, the potential applications of magnetic nanoparticles in removing arsenic have been highlighted. It is envisaged that advances in material science and nanotechnology will create unique magnetic nanoparticles with even better performance. Combining hybrid materials and surface alterations can increase their effectiveness in wastewater treatment settings.

Bubble generation mechanisms in microchannel under microgravity and heterogeneous wettability

Advances in hybrid surfaces have revealed interesting opportunities for multiphase flow control under microgravity, as the surface tension force is dominant in this condition. However, a comprehensive investigation of bubble generation rates and slug flow parameters remains challenging. This research integrates hybrid wettability and modified dynamic contact angle models to address this important knowledge gap. Using the computational capabilities of the IsoAdvector multiphase method, we performed detailed simulations of complex multiphase flow scenarios with the OpenFOAM package. We then validated these simulation results through rigorous comparison with available experimental data, thereby strengthening the accuracy and reliability of our numerical simulations. Our comprehensive research demonstrates the profound effect of altering contact angle distribution patterns on several critical parameters. These results highlight the precise control that can be achieved through the strategic manipulation of these patterns, offering the possibility of adjusting factors such as bubble production rate, slug length, bubble diameter, the relationship of flow residence to bubble movement, bubble movement speed in the channel, and pressure drop. Interestingly, altering these patterns can also induce asymmetric behavior in bubbles under microgravity conditions, a phenomenon that has significant implications for various applications. Such insights are crucial for fields such as heat transfer in energy systems, reaction mechanisms in chemical processes, multiphase flow control in petrochemical industries, fluid dynamics in aerospace engineering, and cooling mechanisms in electronic devices. With the ability to modulate these fundamental parameters, we gain valuable insights into the design and optimization of microchannel systems. Consequently, this research presents a more efficient and innovative approach to multiphase flow control, promising improved operational performance, and efficiency in various engineering applications.

Strong plasmon-mechanical coupling through standing acoustic waves and antenna enhancement, toward mass transduction

Plasmon-mechanical resonators are frequently employed in sensor development. Here, I report the coupling of plasmon and mechanical modes in a multilayer architecture. In the experiment, the multilayer comprised indium tin oxide (ITO) and silver (Ag) mirrors placed on the top and bottom of a SiO2 substrate. By activating a Fabry–Pérot hybrid mode and surface plasmon polariton in a Kretschmann configuration, I demonstrated the generation of a hybrid plasmon-mechanical mode by plasmonic dispersion and through strong coupling, which resulted in mechanical distortion at multiple frequencies. Adsorption of rhodamine G6 on Ag modifies the optomechanical spectrum; it causes eigenmodes to split, resulting in a coupling rate greater than the optical decay rate (κ∗<g). Besides, the excitonic modes were observed to interact with plasmon-mechanical modes, especially on-resonance, where the plasmon-mechanical modes exhibited the higher intensity. For example, the out-of-phase flexural mode (iii, g0=427×2πkHz) became active because of the coupling of the dye. Meanwhile, after dye absorption, the strong in-phase compressional mode (iv, g0=560×2πkHz) exhibited the widest splitting and an increase in the side peaks, which merged when the pump power was raised. The system was then analyzed to determine the ideal experimental settings for detecting mass by the oscillator in a controlled experiment. The mass sensor responsivity was evaluated to be F=1017Hzg−1. Advantages and disadvantages of this approach are presented.

Numerical investigation into impact of halide perovskite material on the optical performance of prism-loaded hybrid surface plasmon resonance biosensor: A strategy to increase sensitivity

The technology of surface plasmon resonance (SPR) is widely recognized and valued for its ability to rapidly and sensitively investigate biomolecular interactivities in real-time. Herein, we numerically investigate the collective influence of metal/ transition metal dichalcogenide (TMDC)/halide perovskite (HP)/2D carbon (C) and phosphorus (P) allotropes on the functionality of an SPR biosensor deploying Kretschmann configuration. The incident light wavelength is held constant at 633 nm, and radiative properties of the hybrid structure are determined using the attenuated total reflection and transfer matrix techniques. Crucial performance metrics such as quality factor (QF), figure of merit (FoM), sensitivity, and detection accuracy are calculated. The comparison is conducted and evaluated against the current literature using performance outcomes in terms of several prisms such as BK7, BAK1, BAF10, SF5, SF10, SF11, 2S2G, CaF2, and CsF, several TMDCs such as WS2, MoS2, WSe2, MoSe2, and PtSe2, several HPs such as CsPbI3, KSnI3, CsSnI3, and FASnI3, and 2D C/P allotropes such as Graphene, MXene, Black phosphorene (BP), and Blue phosphorene (BlueP) in order to search optimum parameters, and then we implement the best one in each layer of this biosensor design. It is noticed that the SPR heterostructure based on BAK1 prism, plasmonic metal Ag, tungsten disulfide (WS2) TMDC, formamidinium tin iodide (FASnI3) HP and 2D BP exhibits outstanding performance with regard to sensor performance characteristics. The observed FoM and sensitivity are 48.2/RIU and 402°/RIU, respectively. The investigation of the electric field distribution within this biosensor along the normal to the interface is also conducted using the finite difference time domain (FDTD) approach to demonstrate the unique contribution of FASnI3. The findings presented in this study are anticipated to play a key role in the improvement of plasmonic resonance-based biosensing domains like DNA hybridization or formalin detection by employing halide perovskite as an additional layer in SPR biosensors.

Rationally designed ultra-fast laser surface texturation of biocompatible temporal scaffolds

The aim of the current work is to create 2D silk fibroin and 3D calcium phosphate temporal cellular scaffolds with specifically enhanced porous topographical design by means of femtosecond laser-induced nano- and micro-scale hybrid surface structuring for application in muscle and bone tissue engineering. The created cellular matrices were ablated in a multistep manner using a Solstice Ace system, delivering laser pulses with pulse duration of 70 fs, at λ=800 nm and a focus spot of 25μm. The samples were positioned on a motorized XY translation stage perpendicular or in a variable angle in respect to the laser beam. Based on the previously performed comparative experimental study, optimal laser structuring conditions and raster patterns were chosen for further enhancement of muscular and Schwann cells environment. The most valuable contribution of the study presented is related to the optimization of the bioactivity properties of the studied cell matrices and their subsequent practical application in tissue engineering.

Al-5052/SiC + CeO2 hybrid surface composites: Achieving improved microstructural and mechanical behaviour via friction stir processing

In the present work, hybrid surface composites (HSCs) were fabricated using aluminium 5052 alloy as base matrix and silicon carbide (SiC) and cerium oxide (CeO2) as reinforcement particles via friction stir processing (FSP) technique. Varying reinforcement ratios of SiC and CeO2 nano-powders, viz 100:0, 75:25, 50:50, 25:75, and 0:100 was used. Multi-pass FSP was employed to obtain improved dispersion of reinforcement particles. Results revealed the collaborative impact of SiC and CeO2 particles on the mechanical properties of the SCs, shedding light on the optimal ratios for achieving superior mechanical performance. The hybrid ratio of (SiC: CeO2) 75:25 was predominant in tensile strength enhancements with an ultimate tensile strength of 283 MPa compared to 269 MPa of BM while the percentage elongation increased to 21.6 as compared to 18.8 in BM. The average microhardness also improved to 92 HV compared to 85 HV. These results emphasised on the importance of HSC fabricated using 75:25 ratio of SiC:CeO2 reinforcing particles.

Insight into role of Co species on NiCo/CeMgAl for ethanol steam reforming: Enhanced activity and resistance to coke

Bimetallic catalysts with unique geometric and electronic structure exhibit high performance compared to that of monometallic counterparts in the ethanol steam reforming (ESR). Herein, NiCo bimetals supported on CeO2 doped MgAl2O4 (NiCo/CeMgAl) with different ratio of Ni/Co were prepared for ESR. The synergies between Ni and Co in catalytic activities and ability to anti-coking were focused. The results demonstrate Co atoms trend to segregate toward the surface and are oxidized synchronously, forming the Ni-CoO hybrid surface. The reduced Ni particles are beneficial to maintain a stable catalytic activity for the C-C bonds scission, and the CoO particles formed by segregation and irreversible oxidation of Co0 are more conducive to activation of H2O, the resulting OH promotes the transformation of CHx species, which significantly reduces the selectivity of CH4 and prevents the formation of filamentous carbon. Controlling Co content and maintaining a stable M/Mδ+ are critical to balance the C-C bond scission reaction and the CH3* conversion reaction on the NiCo bimetallic catalysts. The optimal catalyst 9Ni1Co/CeMgAl shows the ethanol conversion of 93.9 % at TOS of 100 h, and the average rate of coke formation is 0.50 mgc·gcat-1·h−1.