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Scaling up of microbial fuel cells is a challenge for practical applications in wastewater treatment. In addition, the flow control is an important aspect for the electrochemical reactions occurring at the electrodes are influenced by fluid motions. By using dimensionless parameter analysis fluid regimes can be investigated in different scales of reactors. In this study, four important dimensionless flow parameters such as Reynolds number, Peclet number, Schmidt number, and Sherwood number were used for systematic analysis of hydrodynamic effects and power performance of recirculation mode microbial fuel cells together with computational fluid dynamics method. Results showed that the higher value of Reynolds number enhanced the convective flow of anolyte due to the dominant inertial forces in the flow field. Therefore, Reynolds number of 1.6 × 101 were obtained high mass transfer coefficient of 4.76 × 10−7 m s-1 and thin diffusion layer thickness of 2.52 × 10-3 m. Maximum power density and limited current density of 2422.8 mW m-2 and 4736.4 mA m-2 were obtained respectively which were higher than Reynolds number of 0 by 1.61 and 1.69 times. These findings shall be useful for effective recirculation flow mode MFCs power production and have a great possibility for large scale applications.

Ultrafine CoO particles immobilized into the mesopores of three-dimensional cubic bimodal ordered mesoporous carbon CMK-9 is successfully prepared by using a combination of nanocasting and wet-impregnation methods. It is found that the cubic bimodal interconnected mesoporous framework of CMK-9 plays a crucial role in achieving the excellent electrochemical performances by assisting the rapid mass and charge transfer. Among the prepared nanocomposites, CoO(10)@CMK-9 delivers a discharge capacity of 830 mAh g-1 after 200 cycles at a current density of 100 mA g-1 in lithium-ion batteries. At a higher current density of 1000 mA g-1 , the anode presents an outstanding discharge capacity of 636 mAh g-1 after 200 cycles. In sodium-ion batteries, the anode provides a discharge capacity of 296 mAh g-1 after 250 cycles at a current density of 100 mA g-1 . The remarkable performances of CoO(10)@CMK-9 demonstrate the promising potentials of the nanocomposite as the anode for rechargeable batteries.

A facile wet-impregnation process is employed to prepare ultrafine SnO2 nanoparticles that are confined in three dimensional interpenetrating cubic ordered mesoporous carbon. The nanocomposite that is composed of SnO2 and ordered mesoporous carbon serves as a promising anode in lithium-ion batteries. Successful confinement and crystallization of SnO2 nanoparticles are confirmed by a variety of characterization techniques including nitrogen adsorption-desorption isotherms, X-ray diffraction, selected area electron diffraction patterns and transmission electron microscopy. The nanocomposite anode delivers an initial reversible capacity of 1093 mA h g−1 with capacity retention of 66 and 57% after 100 and 500 cycles, respectively, and Coulombic efficiency value of over 99%, excluding a few initial cycles at a high current density of 780 mA g−1. The nanocomposite anode exhibits remarkable performance with discharge capacities of 1282 and 947 mA h g−1 after 2nd and 130 cycles, respectively, at a current density of 200 mA g−1. When higher current densities of 1600 and 4000 mA g−1 are employed to the cell, satisfactory reversible capacities of 529 and 228 mA h g−1, respectively, are obtained. The remarkable capacity, rate capability and cycling stability of nanocomposite anode demonstrate its great potential for use in high-performance lithium-ion batteries.

PtFe nanocrystals hybridized by one rare-earth metal oxide (i.e., CeOx) (namely PtFe-PtxFeyCezOj) with controlled compositions and gradient microstructures are synthesized continuously in a simple programmed microfluidic process. Their electrochemical catalytic performances are evaluated by methanol oxidation reaction (MOR), oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER). TEM, EDS, XRD and XPS measurements are used to characterize their microstructures and compositions. Results suggest that PtFe-PtxFeyCezOj nanohybrids have overall sizes around 2 nm, showing gradient structures composed of PtFe rich inner parts and cerium oxide rich outer layers. They preserve angular shapes and rough surfaces, whose atoms have metallic states and/or multi-oxidation states. The electrochemical catalytic measurements indicate that PtFe-PtxFeyCezOj nanohybrids exhibit excellent electrochemical catalytic performances in MOR, ORR and HER. Particularly, the PtFe-PtxFeyCezOj nanohybrids with the designed atom ratio of Fe:Pt:Ce = 1:1:1 show the best MOR performance, with a forward peak current of 1018.6 mA/mgPt, which is 5.6-fold enhancement compared to the commercial Pt/C catalysts (180.8 mA/mgPt), and the best ORR performance, with a specific activity of 3.28 mA/cm2 and mass activity of 0.73 A/mgPt, which are 6.0- and 4.6-fold enhancement compared with the commercial Pt/C catalysts (0.55 mA/cm2 and 0.16 A/mgPt). It also gives HER a much low Tafel slope (19 mV dec−1) comparing with those previously reported. Chronoamperometry tests suggest that PtFeCe1 catalysts can maintain 2-fold activity of commercial Pt/C catalysts at the end of 4000 s’ operation. TEM images of nanohybrids before and after electrochemical catalytic tests confirm that the suitable coating of CeOx prevents the PtFe nanohybrids from intensive etching and dissolving in the strong acidic reaction electrolytes and improves the durability and microstructure stability of these nanohybrids. The greatly improved catalytic performances are fundamentally resulted not only from the synergistic interface effect between the PtFe alloy rich inner parts and the cerium oxide rich outer layers, but also from the electron orbital hybridization effects among Pt, Fe and Ce atoms. This study provides a new methodology in the microstructure design and controlled synthesis of efficient multifunctional nanocatalysts with stable microstructures by hybridizing rare-earth metal oxides to form stable thin outer-layers. These stable nanocatalysts shall preserve valuable applications in fuel cells and hydrogen production by water splitting.

Ultra-small cobalt nanoparticles (NPs) are successfully confined within the mesopores of cubic mesoporous silica KIT-6 via a facile chemical reduction process using double reducing agents sodium borohydride (NaBH4) and ammonia borane (NH3BH3, AB). When the Co NPs embedded KIT-6 catalysts are used as catalysts for generation of hydrogen from hydrolysis of NH3BH3 a superior turnover frequency (TOF) of 20.05 m o l H 2 m o l C o - 1 m i n - 1 and lower activation energy of 32.6 kJ mol−1, better than most of the Co-based catalysts, are achieved. The higher catalytic activity is mainly attributed to the ultra-small size (2.5 nm) of Co NPs and uniform dispersion of Co NPs in the mesopores of KIT-6. Co NPs are also prepared using KIT-6 as the support with another two synthesis routes, namely, single reducing agent NaBH4 and thermal reduction method for comparative study. However, the resulting Co NPs are much larger in size and hence have less catalytic activities. The Co NPs are synthesized within the hexagonal mesopores of SBA-15 as well using double reducing agents in order to study the effect of the pore structure of the support on hydrogen generation. KIT-6 supported Co NPs can produce hydrogen much faster than the SBA-15 supported Co NPs as the 3D interconnected porous structure of KIT-6 allows homogenous transportation and easy diffusion of NH3BH3 molecules to the active sites. The Co NPs in KIT-6 exhibits good recycle ability up to 5 cycles, and the catalyst can be recovered economically from the aqueous solution due to its magnetic nature.

A nanocomposite cathode based on LiFePO4 (LF) nanoparticles embedded 3D cubic ordered mesoporous carbon CMK-8 for lithium-ion batteries is synthesized by a facile impregnation method followed by further modification with carbon coating. The effects of variation of carbon contents on electrochemical performances of cathodes are investigated. The highly crystalline nanophase of LiFePO4 particles is confirmed by X-ray diffraction and TEM analysis. Nitrogen adsorption–desorption isotherms reveal persistence mesoporosity after encapsulation of LiFePO4 nanoparticles. The graphitic phase in LF/C@CMK-8-X (X = amount of CMK-8) nanocomposites is detected by analyzing the Raman spectra of the matrix carbon due to CMK-8 and the coated carbon (C). The electrochemical properties of the LF/C@CMK-8-X nanocomposites are evaluated with cyclic voltammetry, impedance spectroscopy, and charge–discharge cycling. The excellent rate capability with a discharge capacity value of 184.8 mA h g–1 is obtained for LF/C@CMK-8-0.5 nanoc...

Cubic mesoporous silica nanoparticles (MSNs) with the SBA-1 moiety, functionalized with carboxylic acid ( COOH) groups as well as enlarged mesopores, are successfully synthesized using tetraethyl orthosilicate (TEOS) and carboxyethylsilanetriol sodium salt (CES) as silica sources, complexes formed by polyacrylic acid (PAA) and hexadecylpyridinium chloride (CPC) as templates, and trimethylbenzene (TMB) as pore expander. The successful incorporation of organic functionalities are confirmed by 13C and 29Si solid-state NMR. The structural properties of cubic mesostructures are characterized by powder XRD, N2 adsorption-desorption isotherms, and TEM measurements. The prepared MSNs exhibit a remarkably high adsorption capacity of 1138 mg g−1 at pH 8.2 when they are used as the supports to immobilize papain. Both factors of the large pore size of the support and the favorable electrostatic attractions between the carboxylate groups on the adsorbent surface and the papain molecules play important roles in reaching such a high adsorption capacity. The immobilized papain possesses better thermal stability, pH tolerance, and heat resistance in comparison to the free papain. The materials are also used for selective adsorption of a single protein (papain) from the binary mixture of two different types of proteins (papain and hemoglobin). Our results demonstrate that proteins such as papain and hemoglobin with different isoelectric points and shapes can be effectively separated from their binary mixture by simply tuning the pH of the buffer.

In this study, polysiloxane and polyetherdiamine based comb-shaped solid polymer electrolytes (SPEs) are developed by hydrosilylation and sol-gel reactions of polymethylhydrosiloxane, allyltriethoxysilane, bis(2-aminopropyl) polypropylene glycol-block-polyethylene glycol-block-polypropylene glycol and (3-glycidoxypropyl)trimethoxysilane followed by LiClO4 doping. The absence of residual Si‒H functionality in FTIR and 29Si CPMAS NMR spectra confirms the completion of hydrosilylation reaction. The formation of comb-shaped SPEs with silicate backbones is confirmed by 13C and 29Si solid-state NMR spectroscopy. The maximum ionic conductivity value of 5.8 × 10−4 S cm−1 is obtained for the SPE with [O]/[Li] ratio of 16 at 80 °C with electrochemical stability window reaching up to 4.8 V. The fabricated electrochromic device with the hybrid SPE of [O]/[Li] = 16 demonstrates good electrochromic contrast and optical density change values of 49.3% and 0.39, respectively, at wavelength of 550 nm. The results show that the present comb-shaped SPEs have potential to be used in various electrochemical devices.

In this study, a sub-class of microporous crystalline metal organic frameworks (MOFs) with zeolite-like configurations, i.e., zeolitic imidazolate frameworks of single node ZIF-67 and binary nodes ZIF-Co/Zn are used as the supports to develop Cu nanoparticles based nanocatalysts. Their catalytic activities are comparatively evaluated where Cu(x)@ZIF-Co/Zn exhibits better performances than Cu(x)@ZIF-67 in the reduction of synthetic dyes and nitroarenes. For instance, the Cu(0.25)@ZIF-Co/Zn catalyst shows an excellent reaction rate of 2.088 × 10−2 s−1 and an outstanding activity of 104.4 s−1 g cat − 1 for the reduction of methyl orange. The same catalyst also performs an exceptional catalytic activity in the hydrogenation of p-nitrophenol to p-aminophenol with the activity of 216.5 s−1 g cat − 1 . A synergistic role of unique electronic properties rising from the direct contact of Cu NPs with the bimetallic nodes ZIF-Co/Zn, higher surface area of support, appropriate Cu loading and maintainable microporous frameworks with higher thermal and hydrolytic stability collectively enhances the catalytic activity of Cu(x)@ZIF-Co/Zn. Moreover, this catalyst shows excellent stability and recyclability, which can retain high conversion after reuse for 10 cycles.

Microbial fuel cell (MFC) technology is being given immense esteem in the scientific community for its capability of transforming organic waste directly into electricity through electrochemical reactions occurring at the microbial catalyzed anode, and microbial or abiotic cathode The microbes in a MFC transfer the electrons to the electrode through various electron transfer mechanisms and among them, nanowire transfer mechanism is the most significant one. The purpose of this study was to design and develop mathematical models for predicting the nanowire electron transfer mechanism. Results obtained from the experiments and simulations are found to be well in agreement with each other. These evidences prove that electron transfer mechanisms do occur in the microbial biofilm of the MFCs. In addition, these results imply that the f electron transfer mechanism may lead to an increase in power generation from the MFC. Biofilms with thicknesses of 2 μm and 1 μm have enhanced a current density increase of 86% and 73% respectively than that of 3 μm thick biofilms. Thus, it was observed that the biofilm thickness had a very less influence on the performance of MFC and these results can contribute to the development of MFC in the field of energy generation.

TiCrSiN thin films were successfully grown using a hybrid approach in which a high power impulse magnetron sputtering (HiPIMS) power was combined with a radio frequency (RF) power. Different Si contents were obtained by changing the RF power of Si target. The ion energy distribution functions (IEDFs) showed that the energy tails of all sputtered ions from the targets and sputtering gases shifted to a higher energy tails when the Si target power increased from 50 to 150 W. The peak power density of the TiCr target powered by HiPIMS and the corresponding Si content in the films increased from 1214 to 1350 W/cm2 and from 0.2 to 17.9 at.%, respectively, as the Si target power increased from 50 to 150 W. The Si atoms were in the form of amorphous Si3N4 phase. The Si content showed a major influence on the microstructure, adhesion and mechanical properties of TiCrSiN film. Although a nanocomposite microstructure was formed when the Si content was 17.9 at.%, lower hardness and acceptable adhesion property were obtained due to a microstructure consisting of small TiN nanograins embedded in a large amount of soft amorphous silicon nitride matrix. The hardness of TiCrSiN film reached a maximum hardness of 31.1 GPa at Si = 6.7 at.% due to the refined microstructure and grain boundary hardening effect.

Applying a porous hydroxyapatite (HA) coating on a titanium substrate is a widely used method to increase the biocompatibility and osteogenic potential of human embryonic palatal mesenchymal (HEPM) pre-osteoblasts. Thermal spraying is one of the most prevalent methods used to coat HA on titanium substrates due to its ease in processing and ability to produce coatings with good adherence, which affect positively the surface topography and coating performance. The objective of this work is to enhance the biocompatibility and osteogenic potential of HA coatings on titanium substrates. HA was first synthesized and then coated onto a titanium substrate by two distinct methods, i.e., the dry coating method and the wet coating method. The phase content was evaluated by X-ray diffraction (XRD). The particle morphology was observed by scanning electron microscopy (SEM). HEPM pre-osteoblasts were used to test the cell-material interaction in vitro, and thereafter, an alkaline phosphatase (ALP) test was conducted. The wet coating method enhanced the specific surface area, which in turn increased the cell proliferation on HA-coated titanium substrates. The in vitro test demonstrated that wet coatings resulted in enhanced cell attachment and ALP activity. This study shows that spraying HA using the wet coating method is a technique that can produce potentially bioactive bone-regeneration implants.

This study developed a tubular solid oxide fuel cell (SOFC) anode support layer via atmospheric plasma spraying, which is considered one of the most promising methods for producing SOFCs because of its faster deposition rate and lower cost compared with other film formation processes. Plasma spraying can replace the traditional use of extrusion technology to manufacture the anode base tube, eliminating the need for high-temperature sintering steps. In this study, commercially available powders were used to make the anode of a tubular SOFC from NiO/yttria-stabilized zirconia (YSZ) powder, and Na2CO3 and polymethyl methacrylate were tested as pore-forming agents. The anode composite powder was sprayed on the graphite base pipe, and the final product was changed by altering the spraying parameters and anode powder ratio. The direct current (DC) resistance measurements showed that the conductivity of the Ni/YSZ tubular anode formed with higher power plasma spraying could reach 428.55 S/cm at 800 °C. The experimental results showed that the power and parameters of atmospheric plasma spraying could affect the porosity and electron conductivity of tubular SOFC anodes.

Hydroxyapatite (HA) has good biocompatibility, high strength and low fracture toughness. It is often used as the main material for artificial bones in bioceramics because of the similar composition. In this study, we prepared zinc-doped hydroxyapatite by the co-precipitation method to produce artificial bone material has antibacterial properties, for use in post joint surgery to inhibit bacterial infection or proliferation and ultimately the incidence of osteomyelitis. The co-precipitation method prepared hydroxyapatite with different concentrations of zinc chloride. The experimental results revealed that after sintering, it has some new phases generated of ZnO and CaZn2(PO4)2 when we add zinc chloride that concentration reaches 0.15 M. The minimum inhibition zone revealed the antibacterial ability of Zinc-HA increased when the concentration of zinc chloride increased from 0.0125 M to 0.15 M. The granulated powder of zinc-doped hydroxyapatite was coated on the titanium substrate by the flame-spraying method. The Zinc-HA coating was found with good biocompatibility and antibacterial ability in the biological and antibacterial test.

Factors that affect the power performance of microbial fuel cells (MFCs) are well known to be very complex because of their multidisciplinary character, especially with respect to the electrode. In this study, for the first time, specimens of different metallic materials with smooth and rough surfaces, including Cu-based alloys and porous Ni plates whose sintering temperature was in the range of 900 °C–1100 °C, were investigated with regard to their possible application as anodes in MFCs. The results show that MFCs equipped with a Cu–Ag alloy anode could produce a higher power performance with an open-circuit voltage of 0.65 V and a power density of 1141.69 mW m −2 compared to the other anodes of Cu–Zn and Cu–Ni–Zn alloys. The reason is that the performances of anodes are proportional to the electrical conductivity of the various alloys. In addition, the porosity of the specimens is 20.3% for the Ni-1100 °C and 58.4% for the Ni-900 °C anode material. The conductivity of the anodes decreases with increasing porosity, which, in turn, will result in a lower power performance. Here, the Ni-1100 anode applied in MFCs displays a better performance with an open-circuit voltage of 0.56 V, a limiting current density of 3140 mA m −2 , and a corresponding maximum power density of 448 mW m −2 . The output power density could be maintained at 450 mW m −2 after a test of 50 h.

This study aims to fabricate a porous anode coating for solid oxide fuel cells (SOFC) by the flame spraying. Flame spraying is an easy low-temperature process and offers the advantage of a reduced thermal stress. Due to the low-temperature, the initial selection of the feedstock will affect the deposition of the coating. In this study, two kinds of feedstocks were used. One was the commonly used NiO/8YSZ for anode fabrication. The second was the Ni metal with 8YSZ design for the low temperature flame spray. The special nickel-coated graphite (NiGr) was employed as the pore former. The results show that NiO/8YSZ forms a uniform and flat coating with small-sized pores. The Ni/8YSZ powder forms a rough coating containing large-scale pores. The addition of NiGr into the composite powder increases the porosity and permeability of the anode after graphite burn out and hydrogen reduction. In summary, the use of a Ni/8YSZ/NiGr feedstock yields higher porosity (35–40%), gas permeability (1.37 Darcy), bonding strength (45.6 ± 3.18 MPa) and better anode conductivity.

The purpose of this study is to develop macroporous TCP (tricalcium phosphate) with irregular shape and the use of HA (hyaluronic acid) gel as the lubricating agent of a composite hydrogel for cell carrier. The porous TCP particle with meteorite shape was made by the solid-state reaction by adding different ratios of the PMMA (Poly(methyl methacrylate)). The subcutaneous filler was made by mixing hyaluronic acid gel with TCP particles and live cells. For the in vitro testing, the mouse fibroblasts cell line L929 was employed for analysis of the toxicity and biocompatibility of the material. The cells were cultured on the material for one to three days followed by the WST-1 (Water soluble tetrazolium) and LDH (Lactate dehydrogenase) analysis. The results of LDH and WST-1 showed that the composite HA/β-TCP was not cytotoxicity. The advantage of this product is the meteorite shaped macroporous TCP particle in the hyaluronic acid gel that could form a linkage channel in the gel. When the fat cell mixed with the composite HA/TCP gel, the fat cells will not be covered with the hyaluronic acid for a long time, and hence the cell will not die of hypoxia or the lack of growth factors provided by the subject’s body fluid. As the proliferation of fat cells progressed, it became a good filler of the injected area.

Thin film metallic glasses (TFMGs) have been heavily studied recently due to their ability to improve structural integrity. These versatile materials can furthermore be engineered to encompass biomedical applications in addition to providing improved hardness and other such uses in altering the base materials. In this work, six Zr-Ti-Fe TFMGs were grown by a magnetron co-sputtering system using pure Fe, Zr, and Ti targets under different target power control. The Fe content of coatings increased from to 17.8 to 49.8 at.%. The amorphous phase of each coating was confirmed by X-ray diffraction and transmission electron microscope techniques, and a featureless cross-section microstructure was found for each coating. Very little pile-up was found after the nanoindentation test. The hardness and elastic modulus of TFMG increased from 5.4 to 10.4 GPa and 73 to 135 GPa, respectively, as the Fe content increased from 17.8 to 49.8 at.%. Each TFMG also had adequate adhesion by HRC-DB test. Good biocompatibility of each TFMG was confirmed with proliferation assay using MG-63 cells. Because of the intrinsic improvement on hardness, and the additional properties of biocompatibility, we can conclude that six thin film metallic glass materials show promising possibilities for biomedical application.

Cubic FDU-12 type mesoporous silicas with enlarged pores and carboxylic acid (–COOH) functionality in the pore channels (denoted as LP-FTC-x) are synthesized using tetraethyl orthosilicate (TEOS) and carboxyethylsilanetriol sodium salt (CES) as silica sources, Pluronic F127 triblock copolymer as template, and trimethylbenzene (TMB) as pore expander, and utilized them as supports for enzyme immobilization. When the –COOH content is increased from 0 to 30%, the pore size of LP-FTC-x decreases from 23.6 to 11.1 nm, and its particle size decreases from around 2 μm to 600–800 nm. The material exhibits a high papain adsorption capacity (895 mg g−1) with a low leaching rate at pH 8.2 due to the well-defined surface chemistry in the pore channel. The adsorption kinetics and isotherms follow the pseudo-second-order model and the Langmuir isotherm model, respectively. The excellent structural properties of LP-FTC-x are also advantageous for enhancement in stability of enzyme toward the temperature, solution pH, and incubation time variations.

Highly active Ag-doped Ni nanoparticles are successfully fabricated within carboxylic acid (−COOH) functionalized mesoporous silica SBA-16 by a facile wet incipient technique for catalytic conversion of toxic nitroaromatics. The −COOH groups on SBA-16 play a crucial role by enhancing the electrostatic interactions with Ag(I)/Ni(II) cations, that control the crystal growth during the thermal reduction. Systematic characterizations of SBA-16C and Agx%Ni@SBA-16C are performed by different techniques including solid state 13C and 29Si nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), N2 sorption, X-ray photoelectron spectroscopy (XPS), high resolution transmission electron microscopy (HRTEM) and superconducting quantum interference device (SQUID). The highly dispersed ultrafine Ag-doped Ni NPs (∼3 nm) are well-confined within SBA-16C and exhibit magnetic properties that are extremely beneficial for recycling. The bimetallic Ag2.4%Ni@SBA-16C shows exceptionally high catalytic activity during catalytic conversion of toxic nitroaromatics to environmentally friendly amino-aromatics. The enhanced catalytic activity could be ascribed to the combined effects of unique electronic properties, synergistic effects of Ag-doped Ni, ultra-small size, metal loading, and favorable textural properties. These magnetically separable nanocatalysts show excellent durability.

A new nanocomposite based on three-dimensional ordered mesoporous carbon (OMC) with tubular framework supported SnO2 nanoparticles entangled in MoS2 nanosheets is developed ingeniously by nanocasting and hydrothermal methods. The bimodal mesoporous interconnected architecture of CMK-9 and MoS2 nanosheets host SnO2 nanoparticles inside the mesopores and interlayer regions. Herein, for the first time, electrochemical performances of SnO2/MoS2 heterojunction are explored with an OMC. The present architecture improves the diffusion of ions and conduction of charges, which assist in achieving outstanding capacity, superior rate capability and stable cycle life when the nanocomposite is employed as the anode for lithium-ion batteries (LIBs). Among the nanocomposites, the SnO2/MoS2(1:3)@CMK-9 anode delivers a large initial discharge capacity of 2211 mA h g−1 and an outstanding discharge capacity of 1245 mA h g−1 after 300 cycles with a capacity retention of 96% as compared to the 3rd cycle (1291 mA h g−1) at a current density of 100 mA g−1. At a current density of 1000 mA g−1, the anode provides an exceptional discharge capacity of 823 mA h g−1 after 1000 cycles with capacity retention of 91% as compared to the 3rd cycle. The present architecture of SnO2/MoS2(1:3)@CMK-9 nanocomposite anode with excellent electrochemical performances signifies its potential use in next generation LIBs.

Bimetallic CoCu nanoparticles (NPs) are successfully embedded within the cage-type mesopores of COOH functionalized mesoporous silica SBA-16 by double agent chemical reduction method. The presence of the COOH groups in SBA-16 control the size and dispersion of the CoCu NPs. CoCu@S16LC-20 is used as the catalyst for the hydrolysis of ammonia borane (AB) and reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). The catalytic activity of the CoCu@S16LC-20 outperforms that of monometallic counterparts Co and Cu. In particular, Co40Cu60@ S16LC-20 can release H2 at a rate of 6570 mL min−1 g−1 and reveals superb catalytic activity with a turn over frequency (TOF) of 16.36 mol H2 min−1 molcatalyst−1. The superior catalytic activity of the bimetallic CoCu@S16LC-20 could be ascribed to the strong synergistic effects emerging from the modified electronic structure, smaller particle size, and 3-dimensional (3D) mesoporous silica support. The smaller particle size renders more active sites, and the mesoporous silica support provides easier paths for transfer of reactants to the catalyst. The catalyst magnetic nature permits straightforward recovery from the aqueous solution after reaction completion which enhances the reusability. The bimetallic Co40Cu60@S16LC-20 can degrade 4-NP to 4-AP at rapid rate of 3.85 × 10−2 s−1 in presence of reducing agent NaBH4.

In comparison with the conventional crystalline alloy films, the amorphous thin film metallic glasses (TFMGs) have been reported to exhibit unique properties, such as high strength, improved fatigue property and good corrosion resistance. Among Zr-based TFMGs, the Zr–Ti–Si–W TFMGs have not yet been explored extensively. In this work, quaternary Zr–Ti–Si–W TFMGs were fabricated on Si wafer and AISI 316L stainless steel substrates by a co-sputtering system. The target power of Si target was adjusted to achieve TFMGs with Si contents ranging from 14.3 to 19.7 at.%. For the low oxygen contained Zr–Ti–Si–W TFMGs, the hardness and corrosion resistance increased with increasing Si content. The highest hardness of 8.1 GPa was obtained for the amorphous coating containing the second highest Si content and low oxygen concentration. Highly-dosed oxygen contamination, up to around 9 to 10 at.%, would make the amorphous coating exhibit larger granular surface and columnar cross-sectional microstructure. The high oxygen content also showed detrimental effect to the hardness and the corrosion resistance of coating, due to pronounced surface crack defects. However, similar hardness and corrosion resistance enhancement by the increasing Si concentration were also observed for the high oxygen contained Zr–Ti–Si–W TFMGs. Nevertheless, sufficient adhesion property, good corrosion resistance and acceptable biocompatibility were achieved for five amorphous Zr–Ti–Si–W coatings regardless their oxygen concentration.

Microbial fuel cell (MFC) is a novel technique can solve the waste water problem and generate electricity. This study focuses on the anode material by using co-axial electrospinning method to fabricate polylactic acid (PLLA) microtube array membrane (PLLA MTAM). These MTAM not only have high specific area but also enhance the microbial adhesion ability. The addictive, multi-walled carbon nanotubes (MWCNT), increase the conductivity that can improve the efficiency of MFC. Furthermore, the effects of different numbers of electro spun fiber membrane placed in the anode of dual-chamber MFC on electrical performances are analyzed. The scanning electron microscopy (SEM) images show that MTAM have thin walls and contain pores on its surface which is beneficial for fast mass transport. During acclimation, bacteria regularly accumulate on the surface and formed a lamellar structure. However the bacteria in the inner structure tend to group into individual block. The growth of biofilm obviously affected the electrical performance of the cell. In the acclimation process, more electro spun fiber membranes in the anode raise voltage rapidly due to better electron transfer ability. The use of MTAM as the anode in MFC is beneficial for attaching bacteria in shorter acclimation time. The MFC of 11 MTAMs has a maximum power density of 2.94 mW/m2 and a minimum resistance of 833 Ω. Compared to sealing MTAM, hollow MTAM demonstrate better electrical performance.

In this study, thermally sprayed Inconel 625 coatings were used to improve the corrosion-wear resistance of 304L stainless steel substrates in saline environments. The tribological behavior of various Inconel 625 coatings obtained through flame spraying (F), arc spraying (A), plasma spraying (P), or high-velocity oxygen fuel spraying (H) was evaluated by testing the specimens on a pin-on-disk apparatus with a cup-shaped container that was filled with a 5 wt% NaCl solution or deionized (DI) water. The results indicated that regardless of the testing solution, the corrosion-wear resistance of the Inconel 625 coating specimens was in the order F > A > P > H. Microstructural examination revealed that the oxide within the as-sprayed Inconel 625 coating layer was mainly Cr2O3 and exhibited a higher hardness but lower elastic modulus than the Ni-based matrix. The oxide within the Inconel 625 coating layer is suggested to function as an antiwear phase against the corrosive-wear environment. The high corrosion-wear resistance of the F specimen was attributed to the high oxide content within its coating layer. In addition, all Inconel 625 coatings exhibited higher wear resistance in the 5 wt% NaCl solution than in the DI water, which implied that chloride lubricated the sliding wear, considerably reducing weight loss of the coating after corrosion wear.

Strontium (Sr) and magnesium (Mg) have been reported to promote osteoblastic cell proliferation and to accelerate bone formation. However, the biofunctional effect on osseointegration caused by coating dental implants with hydroxyapatite (HA) incorporating both of these elements has not been investigated to date. The aim of this study was to examine bone formation and osseointegration in Sr- and Mg-doped HA-coated titanium implants. In this study, the flame-spraying technique was used to deposit Sr- and Mg-doped HA onto titanium discs and implants. The biocompatibility and alkaline phosphatase (ALP) activity of human embryonic palatal mesenchymal pre-osteoblasts on titanium discs was evaluated. In addition, the expression of the osteogenesis gene and the protein expression of Runt-related transcription factor 2 (RUNX2), osteopontin (OPN), and osteocalcin (OCN) on titanium discs were determined by using real-time polymerase chain reaction assays, Western blot analysis, and enzyme-linked immunosorbent assays. Ultimately, the effects of Sr- and Mg-doped HA on the osseointegration of implants were examined in beagle dogs. The results showed that of the groups tested, the 5Sr5Mg-HA group exhibited the highest biocompatibility, ALP activity, and mRNA and protein expression of RUNX2, OPN, and OCN. Prominent new bone ingrowth with osteoblasts and osteoid tissue was found in the 5Sr5Mg-HA group at 4 weeks and 8 weeks. In addition, the highest bone-to-implant contact ratio was found in the 5Sr5Mg-HA group compared to other groups at 8 weeks in beagle dogs. The results show the potential of using 5Sr5Mg-HA coating on dental implants for enhanced osseointegration. Statement of Significance Osseointegration is assessed according to the extent of bone-to-implant contact and is an indication of implant success. This study is the first to report that flame-sprayed Sr- and Mg-doped HA coatings on titanium surfaces enhance osseointegration and new bone apposition in a beagle dog model. Therefore, the use of titanium implants incorporating Sr and Mg might be advantageous for patients with a low bone density.

Cubic mesoporous silica SBA-1 functionalized with carboxylic acid (-COOH), namely S1B-C10, is used as a support to fabricate and confine Ru nanoparticles (NPs). The uniformly dispersed organic functional groups in SBA-1 are beneficial in attracting Ru cations, and as a result, homogenously distributed small sized Ru NPs are formed within the mesopores. The prepared Ru@S1B-C10 is utilized as a catalyst for H2 generation from the hydrolysis of ammonia borane (AB). The Ru@S1B-C10 catalyst demonstrates high catalytic activity for H2 generation (202 mol H2 molRu min−1) and lower activation energy (24.13 kJ mol−1) due to the small sized Ru NPs with high dispersion and the support’s interconnected mesoporous structure. The nanosized Ru particles provide abundant active sites for the catalytic reaction to take place, while the interconnected porous support facilitates homogenous transference and easy dispersal of AB molecules to the active sites. The catalyst demonstrates good recycle ability since the accumulation and leaking of NPs throughout catalysis can be effectively prevented by the support.

Hydrodynamic boundary layer is a significant phenomenon occurring in a flow through a bluff body, and this includes the flow motion and mass transfer. Thus, it could affect the biofilm formation and the mass transfer of substrates in microbial fuel cells (MFCs). Therefore, understanding the role of hydrodynamic boundary layer thicknesses in MFCs is truly important. In this study, three hydrodynamic boundary layers of thickness 1.6, 4.1, and 5 cm were applied to the recirculation mode membrane-less MFC to investigate the electricity production performance. The results showed that the thin hydrodynamic boundary could enhance the voltage output of MFC due to the strong shear rate effect. Thus, a maximum voltage of 22 mV was obtained in the MFC with a hydrodynamic boundary layer thickness of 1.6 cm, and this voltage output obtained was 11 times higher than that of MFC with 5 cm hydrodynamic boundary layer thickness. Moreover, the charge transfer resistance of anode decreased with decreasing hydrodynamic boundary layer thickness. The charge transfer resistance of MFC with hydrodynamic boundary layer of thickness 1.6 cm was 39 Ω, which was 0.79 times lesser than that of MFC with 5 cm thickness. These observations would be useful for enhancing the performance of recirculation mode MFCs.

Recently, the plasma electrolytic oxidation (PEO) process has been widely studied and applied in the industrial setting due to its ability to create functional oxide layers on Al, Ti, Mg , and Zr alloys. In this work, a pulsed direct current (DC) power supply was adopted to grow the zirconia coating on pure Zr metal by PEO treatment. A fixed frequency of 1000 Hz and constant current of 2 A were used to fabricate all zirconia coatings. Duty cycle values of 25%, 75%, and 100% were used and 0.1 M K3PO4 aqueous solution containing three different concentrations of KOH, 0.01, 0.05 and 0.1 M, was also used in fabrication. The plasma breakdown voltage decreased with increasing KOH concentration due to its higher electrolyte conductivity. The PEO oxide coating consisted of a thin continuous barrier layer and a thick porous outermost layer, which consisted of mainly monoclinic and minor tetragonal ZrO2 phases. The PEO treatment of Zr metal provided excellent corrosion resistance in Hank's solution and good biocompatibility for 3T3 and MG63 cells. These results suggest that PEO coatings having potential applications in the biomedical field were confirmed in this study.

This study synthesized spinel LiMn 2 O 4 materials using a solid-state reaction processing technology. Neutral surfactants and the tri-block copolymer P123 (template) formed an organic self-assembly in alcohol (solvent), with LiCH 3 COO·2H 2 O and Mn(CH 3 COO) 2 ·4H 2 O as precursors of the inorganic skeleton. Changes in the structure, particle size, and surface area of LiMn 2 O 4 powder in relation to different surfactant contents were investigated. The changes in surface area should affect the wetting effect of the electrolyte on the cathode material, thereby further influencing the actual reaction area and charge–discharge efficiency. The results were analyzed to assess the effect of surface area on electrochemical performance of LiMn 2 O 4 cathode materials. X-ray diffraction (XRD) analysis data showed that LiMn 2 O 4 materials synthesized through the solid-phase reaction method are single-phase spinel, whose original structure is unaffected by the addition of surfactants. Scanning electron microscopic (SEM) observation revealed that LiMn 2 O 4 forms different spherical particles after the addition of different concentrations of surfactants. Furthermore, Brunauer–Emmett–Teller (BET) analysis showed that specific surface areas of 0.4–1.2 m 2 /g are relatively effective in enhancing the capacitance, similarly the formation of spherical particles is beneficial in enhancing the capacitance, and the high-current discharge efficiency is similar to the low-current discharge efficiency. As for the different concentrations of P123, the experiments added with 1.42 M P123 achieved optimum results.

In this study, a (La0.8Sr0.2)0.98MnO3 protective layer was prepared on the C276, Crofer22 APU, SUS304, and SUS430 alloys by the atmospheric plasma spraying technique (APS). The oxidation behavior and electrical property of these metal alloys have been investigated isothermally at 800 °C in air for up to 300 h. Results showed that the ferritic steels transform into MnCr2O4 spinels and a Cr2O3 layer during isothermal oxidation. The C276 alloy formed NiCr2O4 and FeCr2O4 layers; these are protective and act as an effective barrier against chromium migration into the outer oxide layer, and the alloy demonstrated good oxidation resistance and a reasonable match to the coefficient of thermal expansion of the substrate and a low-oxide scale area-specific resistance. The ASR effects on the formation of oxide scale have been investigated, and the ASR of coated samples was below 0.024 Ω·cm2. It has good electrical conductivity for SOFC in long-term use.

Radio frequency (RF) sputtering is a potential medical device coating technology that is commercializable; however, a suitable commercialized target for sputtering the hydroxyapatite (HA) coating onto titanium medical devices is more important. Therefore, this study used three HA targets in conducting sputtering experiments for HA films, which were manufactured in a laboratory by using three different processes: cold pressing and sintering (CPS), hot isostatic pressing (HIP), and atmospheric plasma spraying (APS). Subsequently, the sputtering performance of each type of target and the properties of the HA films were assessed to develop an appropriate process for modifying the surfaces of medical devices. The experimental results showed that the APS target, with a density of approximately 2.83 g/cm3, was suitable for use in HA sputtering. Additionally, the APS target could withstand a high discharge power over 300 W, whereas the CPS target could nearly endure a power below 70 W. The APS target, with Ca/P ratio of 2.401, consisted of a combination of HA, α-tricalcium phosphate (α-TCP), β-TCP, and tetracalcium phosphate phases (TTCP). In addition to being able to perform at a high sputtering power of more than 300 W, the APS target achieved a higher deposition rate than did the CPS target. This study shows that the processing technology used for the APS target is a potential method for applying HA sputtering for the surface modification of artificial aggregates.

Thin film metallic glasses (TFMGs) represent a class of promising engineering materials for structural applications. Despite the effort that has been made in the development of TFMG materials, the iron-based thin film metallic glasses fabricated by sputtering have gained limited attention. In this work, five iron-based Fe–Zr–Ti thin film metallic glasses with different Fe contents ranging from 37.6 to 49.8 at.% were prepared by magnetron co-sputtering system using pure Fe, Zr and Ti targets. Through XRD and TEM analyses, the amorphous phase was confirmed for each coating. The glass transition temperature (Tg) and crystallization temperature (Tx) of TFMG increased with increasing Fe content and reached 963 K and 989 K, respectively, when Fe content was 49.8 at.%. The supercooled liquid region was around 26.3 to 51.6 °C, which was shown to be unrelated to Fe concentration. The hardness, elastic modulus, and H/E ratio of TFMGs increased with increasing Fe concentration. Based on the HRC-DB test, adequate adhesion quality was obtained for all TFMGs. The corrosion resistance of TFMGs also increased with increasing Fe content and spontaneous passivation behavior was discovered due to the large content of Zr and Ti valve metals. Nevertheless, the corrosion resistance of Fe–Zr–Ti TFMGs was strongly influenced by surface defects. A series of high hardness Fe–Zr–Ti thin film metallic glasses with good adhesion property and adequate corrosion resistance was reported in this study.

In this work, aluminum nitride (AlN) thin films were fabricated using the high power impulse magnetron sputtering (HIPIMS) process through the Taguchi method to determine the optimum deposition condition. A L9 array, signal-to-noise (S/N) ratio, and analysis of variance (ANOVA) were applied to study the deposition parameters (pulse frequency, duty cycle, temperature, and substrate bias) with consideration of the microstructure, hardness and transmittance properties of AlN coatings. The wurtzite hexagonal AlN structure was achieved for each coating. Typical fine and dense columnar structure was observed for AlN coating. Based on the higher the better concept using S/N ratio and the contribution using ANOVA, the substrate bias was the most influential parameter for the hardness of AlN coating. On the other hand, the duty cycle was important proportionally for the transmittance of AlN coatings. Confirmation tests with optimal deposition parameters were performed to verify the effectiveness of the Taguchi optimization analysis in this work. The maximum hardness of 25 GPa and transmittance of 83.4% were achieved, respectively, for the AlN coatings deposited with optimal deposition parameters.

The aluminum nitride thin film has recently gained importance due to its unique properties, which include good thermal and chemical stabilities as well as dielectric property. In this work, aluminum nitride thin films were fabricated using the high power impulse magnetron sputtering (HIPIMS) technique. Effects of duty cycle and pulse frequency of HIPIMS power on the microstructure and mechanical property evolution of AlN coatings were explored. The ionization ratio of Al+ species in HIPIMS plasma was characterized to be around 55%. The peak power density increased to 1.60 kW cm− 2 as duty cycle decreased to 3.5%. The deposition rate increased from 1.74 to 4.50 nm/min as repetition frequency reached to 833 Hz at a fixed duty cycle of 3.5%. Strong preferred orientation of hcp-AlN (002) was discovered for AlN films with lower oxygen contamination. In addition to the hcp-AlN phase, the α-Al2O3 phase was found when the oxygen concentration was higher than 3.0 at.%. The hardness enhancement effect was brought by the HIPIMS technique. The hardness increased with decreasing duty cycle and increasing peak power density. Greater hardness of around 26.5 to 28.0 GPa was achieved for the crystalline over-stoichiometric AlN thin film when the coating was fabricated using a 3.5% duty cycle. Meanwhile, the adhesion property was improved with increasing duty cycle and frequency. The AlN coating with both high hardness of 27 GPa and adequate adhesion property was fabricated at a repetition frequency of 1250 Hz and duty cycle of 3.5%.

Microbial fuel cells (MFCs) use microorganisms to convert organic matter into electricity. In order to enhance the mass transfer of MFCs, four types of simplified flow channels, without flow obstacles (square, circular, divergent and convergent), were designed and applied to the anode/cathode channels of MFCs. The simulation analysis showed that the four types of simplified flow channels without flow obstacles obtained a better flow mixing efficiency with an Aspect Ratio (AR) of 1 at a Reynolds number (Re) of 60. A maximum power density of 617.8 mW/m 2 and a COD (chemical oxygen demand) degradation ratio = 9.9% were obtained by the MFCs with the convergent types of flow channels without flow obstacles. This is because the flow mechanism (convection and vortex flow) generated by convergent types of flow channels decrease the mass transfer and ohmic losses. Therefore, this concept of the simplified flow channel without flow obstacles will be useful to the application of MFCs in the future.

We investigated the residual strain of each membrane electrodes in plasma-sprayed solid oxide fuel cell (SOFC), which are under the cyclic redox treatments. The results show that all of the components of SOFC reveal compressive residual stress after plasma spraying. However, the stress states of these components become complicated and irregular after the redox treatments. The strain state of both LSCM (La 0.75 Sr 0.25 Cr 0.5 Mn 0.5 O 3 − δ ) buffer layer and anode was changed from compressive to tensile. We also found that the original stress state was changed when the upper component was deposited. For example, the original stress state was 0.78% in compressive; after the NiO/LDC (Ce 0.55 La 0.45 O 3 − δ ) anode deposited on the LSCM buffer, the anode side of LSCM revealed the compressive strain with 3.34% and the matrix side of LSCM revealed the tensile strain with 10.65%. Two kinds of strain states coexisted in an electrode coating resulted in the electrode failure occurred in the reverse position of stress states. Therefore, the redox treatments indeed affect the strain state of the SOFC components and the influences on the cell durability should not be ignored. The more research results will be described in detail.

In this work, nitrogen contained and B doped ZrCuAlNi thin film metallic glass composites (TFMGCs) were grown by magnetron co-sputtering process. Boron element was doped to evaluate its influence on the microstructure and mechanical properties of nitrogen contained TFMGCs. The supercooled liquid region of TFMG was determined by the differential scanning calorimetry (DSC) analysis. The microstructure was analyzed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The phase structure was confirmed by using X-ray diffraction (XRD). The mechanical properties were measured by nanoindentation. The scratch tester and tests were employed to evaluate the adhesion and tribological properties. The surface roughness was determined by atomic force microscopy (AFM). It was concluded that the surface roughness, microstructure, glass-forming ability and mechanical behaviors of TFMGCs were strongly influenced by the nitrogen and boron doping. The ZrN nanocrystallites were embedded in the amorphous matrix. The hardness, H/E ratio, and indentation toughness increased with increasing boron concentration. Excellent adhesion quality was also confirmed for all coatings. The Zr-based thin film metallic glass composite containing 6.4 B–32.6 N (in at.%) with optima hardness, 16.2 GPa, adequate indentation toughness and excellent adhesion quality was achieved in this work.

High power impulse magnetron sputtering (HIPIMS) is a newly developed coating technology, characterized by its ultra-high peak current and peak power density to achieve unique thin film properties, such as high hardness, good adhesion and tribological performance. In this study, an AlCr alloy target was used to deposit Al x Cr 1 − x N coatings on various substrates by the HIPIMS technique. The aim of this work was to systematically study the microstructure evaluation and mechanical properties of Al x Cr 1 − x N coatings as a function of duty cycle and pulse frequency. The experimental results showed that the peak power density increased linearly as the duty cycle decreased from 5% to 2% at constant frequency of 1000 Hz. A maximum peak power density of 2.76 kW cm − 2 was achieved at the duty cycle of 2% and repetition frequency of 833 Hz. A mixture of cubic and hexagonal Al x Cr 1 − x N phases was found for each coating. The x value of Al x Cr 1 − x N thin films changed from 0.72 to 0.75 and showed no direct relationships with duty cycle and repetition frequency. The peak power density had great influence on the microstructure evolution and altered the microstructure from coarse columnar to fine columnar structure. Re-nucleation grains were also found between columnar grains. The hardness increased with increasing frequency at constant duty cycle of 2% and reached the optimum hardness of 39.9 GPa at x = 0.75. Good adhesion and wear resistance was observed for each coating. The critical load increased as the repetition frequency increased from 500 to 1250 Hz at the same duty cycle of 2%. Since the wear resistance for each coating was excellent, the duty cycle and pulse frequency showed limited influence on the wear resistance of thin films.

In the spraying process, residual stresses are unavoidably developed in coatings due to the differences in thermal expansion coefficients, and cooling conditions between the coating and the substrate. A significant residual stress may lead to micro-cracks in the film or cause the film to peel off the substrate. Therefore, in this work, the biaxial residual stress states of a SOFC anode with various spraying conditions by using the “sin2ψ” technique of the XRD method were studied. The results show that the NiO/LDC coating on the porous Ni substrate with high temperature displayed the lowest compressive residual stress. The compressive residual stress in the NiO/LDC anode decreases with the increase of the Ni substrate temperature during the plasma spraying. In addition, the coating thickness didn't show the obvious effect on the residual stress. Moreover, the compressive stress will promote the tendency of coatings to debond or curve all the cell components.

The purpose of this study is to obtain a favorable combination of biocompatibility and mechanical properties for dental implants by developing process parameters for plasma-sprayed hydroxyapatite (HA) coating on titanium (Ti-6Al-4V ELI) surfaces. The plasma spraying experiments in this study, involving different process parameters of HA coating (coating thickness up to approximately 120 μm), are divided into four stages. An immersion test for the HA coatings in a simulated body fluid (SBF) was performed after HA coating. After 28 days, the crystallinity level of the HA coatings in the SBF increased from 54.88% to 74.39%, and the released calcium ion concentration increased from 44.9 ppm up to 79.27 ppm. Phase III involved investigating the differences in nozzle transverse speeds and surface speeds between disk- and rod (4.5 mm in diameter)-shaped substrates for plasma HA spraying. The results of Phase III reveal that nozzle transverse speeds of 400 mm/s and titanium surface speeds of 5 rpm may be optimal for the titanium rods. Finally, Phase IV entailed using the parameters alternating from Phase III to perform HA plasma spraying on dental implants measuring 4.5 mm in diameter. An SEM morphology examination indicated that the coverage level of the HA coating was nearly uniform and the thickness was approximately 47–130 μm. This study successfully applied plasma spray technology to an HA spray for titanium surface modification. The evaluation and characterization of the resulting HA coatings reveal that the Phase IV parameters may be used for HA-coating on titanium dental implants. The coatings contained no significant phase components such as tricalcium phosphate (α-TCP, β-TCP) or tetracalcium phosphate (TTCP).

In this study, the preparation of mesoporous TiO2 was based on an evaporation-induced self-assembly (EISA) method that used Pluronic P123 as the structure-directing agent and TBOT as the titanium source. We added TBOT to the P123 surfactant that was dissolved in ethanol and then added HCl to this mixed solution with stirring at 25 °C. Then, the thin film of sol was prepared on the Ti substrate through spin-coating. The result was allowed to be sampled in an open Petri dish as it underwent solvent evaporation at 40 RH% and 35 °C for 24 h, and then the samples were calcined for 1 h at various temperatures from 150 to 450 °C. Finally, the mesoporous TiO2 array was formed on the Ti substrate. The mesostructures of the samples were characterized by a small angle X-ray diffraction on the 13A1 beam line at the National Synchrotron Radiation Research Center (NSRRC, Taiwan). The result demonstrates that the sample prepared with a P123/TBOT mole ratio of 0.6 clearly shows a main peak at 0.2° to 0.25°, thus revealing the presence of a hexagonal phase mesostructure. The mesoporous TiO2 film calcined at various temperatures between 150 and 450 °C revealed that the calcination temperature of 250 °C is the optimal temperature for the ordered mesoporous TiO2 that grew on the Ti substrate. The microstructures revealed that the tubular mesopores are arrayed on the Ti substrate. In vitro bioactivity appraisement results show that apatite was formed on the coating surface after immersion in simulated body fluid (SBF) for 3 weeks, which indicates that the mesoporous film has the potential for chemical bonding with bone tissue after being implanted into an animal body.

High internal resistance issue in microbial fuel cell will decrease the power performance and need to overcome. In this study, same working surface area of carbon cloth (CC), aluminum-alloy mesh (ACM) and aluminum-alloy mesh composite carbon cloth (AAMCC) will be applied to act as electrodes for realizing their individual power performance. Results show that AAMCC could provide the largest adhering surface and the lowest equivalent resistance because of the appearance of electrical double-layer. The power density of 2966 mW/m 2 achieved by using AAMCC is higher than CC and ACM electrodes 132.4 and 1497 times, respectively. These evidences show that AAMC electrode can enhance electrical properties significantly and useful to improve the electrode of anode and the cathode in microbial fuel cell.

The present study investigates the antibacterial properties of CuCrO 2 thin film surfaces against Escherichia coli ( E. coli ) bacteria. Single-phase delafossite type copper-chromium oxide (CuCrO 2 ) thin films were prepared on glass substrate by radio-frequency (RF) magnetron sputtering, followed by two-step post-deposition annealing at 400 °C with 5% forming gas and at 600 °C in a nitrogen atmosphere. The structure of the CuCrO 2 thin films was confirmed by X-ray diffraction. The transmittance properties were measured by a UV–Vis spectrometer. The ISO 22196 method was utilized to evaluate the colony forming unit (CFU) of E. coli on the CuCrO 2 surface after several hours. The experimental results find the CuCrO 2 surface to exhibit superior antibacterial performance and an optical transparency of >70% in the visible region with a thickness of 100 nm. A novel transparent antibacterial coating has been demonstrated in the present study.

In the present study, porous electrode coating of Ni/8YSZ on the interconnector material was made by the plasma-spraying. By introducing the pore former into the composite powder, the porous structure of SOFC anode will be obtained. By using the plasma spraying technique for SOFC fabrication, we can avoid the thermal failure between the components of SOFC which made from the traditional sintering method at high temperature. In this study, two kinds of composite powders in the granulate form were prepared, one with the nano carbon as a pore former and the other without the carbon. The results showed that the porous structure of SOFC anode could be achieved by the plasma spraying technique. The porosity of the anode made from the composite powder with pore former was 40%. Without pore former the porosity in the anode coating after hydrogen reduction was almost 30%. These results suggest that this method exhibits the potential to manufacture the porous ceramic/metal composite anode of SOFC to achieve the larger triple phase boundary for fuel oxidation.

By using the atmospheric plasma spraying (APS) technique for SOFC fabrication, we can avoid the thermal failure between the components of SOFC which made from the traditional sintering method at high temperature. The advantage of porous metal supported SOFC produced by the APS process is that the process is simple and low cost. The purpose of this study was to manufacture a porous Ni/CeO 2 anode of intermediate temperature SOFC. By introducing the pore former into the feedstocks, the porous structure of the Ni/CeO 2 anode was obtained by plasma spraying method. In this study, the feedstock of the NiO/CeO 2 /Na 2 CO 3 powder made by the spray granulation is spherical; the powder structure is compact and a hollow hole inside the powder, hence more porosity (29.1%) of the as-sprayed coating was found and the pore distribution is more uniform. The remainder oxygen vacancies are existed in the reduced anode coating. Use of undoped ceria as an anode material appears to be feasible. The NiO/CeO 2 /Na 2 CO 3 powder formed the higher bonding strength coating with 33.6 MPa. The electron conductivity was obtained with around 200 S/cm in 700 °C. The other properties of the anode were discussed in the paper.

In the past studies, the various results of the residual stresses in the hydroxyapatite coatings (HACs) prepared vis the plasma spraying were investigated; some arguments discussed in these studies especially focused on the stress values and the stress states (i.e. tension or compression). In this study, in order to obtain the complete and accurate value and state of the residual stress, the nonstressed free HAC slice was separated from the substrate. According to the curvature theory, the liner residual strain and curvature strain of HAC were obtained. For the purpose of inferring the generation mechanism of residual stress, the particular types of the substrate and different directions of cooling jets were employed. The results showed that the difference of temperature between the HAC and substrate is the main factor that dominates the states of residual stress. HAC on the hollow rotational holder with back cooling from substrate side displayed the higher temperature than titanium substrate (Ti-substrate) during the plasma spraying and resulted in tensile residual stress in the HAC. On the contrary, HAC on the non-hollow holder with front cooling from coating side displayed much lower temperature than Ti-substrate and therefore showed the compressive residual stress. These could be attributed to the differences of volume shrinkage between the HAC and Ti-substrate when the specimen cooled from different initial temperature to room temperature. In other words, the residual stress is not always tensile or compressive; the stress state might be dominated by the cooling directions and the substrate types.

La 2 O 3 –Al 2 O 3 –B 2 O 3 –SiO 2 glasses free of alkaline earth metals were prepared in this study for SOFC applications to relieve the poison caused by BaCrO 4 or SrCrO 4 formation. The apparent densities, coefficients of thermal expansion (CTE), and softening points of the La 2 O 3 –Al 2 O 3 –SiO 2 –B 2 O 3 glasses prepared in this study ranged respectively from 3.24 to 4.54 g/cm 3 , 4.1 to 8.1 ppm/°C, and 912 to 937 °C, depending on the glass composition. The CTE value dropped with the rise in SiO 2 content and escalated with increase in La 2 O 3 content. Crystallization of La 9.51 (SiO 1.0404 ) 6 O 2 and La 4.67 (SiO 4 ) 3 O was observed in part of the glasses after soaking at 800 °C. Two CTE modifiers, MgO and SDC, effectively increased the CTE of La 2 O 3 –Al 2 O 3 –SiO 2 –B 2 O 3 glasses. The composites of selected La 2 O 3 –Al 2 O 3 –B 2 O 3 –SiO 2 glasses and SDC additive on the YSZ substrate were evaluated for use as sealing materials of solid oxide fuel cells (SOFCs). Results indicated that the leakage rates for the composites of A07 glass and 60–70 vol% SDC on the YSZ plate read less than 0.02 (sccm/cm)(kg/cm 2 ) per min at 800 °C. This property seems highly promising for ensuring long-term stability of the sealing materials for SOFC applications.