Biodegradable orthopedic implants are essential for restoring the physiological structure and function of bone tissue while ensuring complete degradation after recovery. Polylactic acid (PLA), a biodegradable polymer, is considered a promising material due to its considerable mechanical properties and biocompatibility. However, further improvements are necessary to enhance the mechanical strength and bioactivity of PLA for reliable load-bearing orthopedic applications. In this study, a multifunctional PLA-based composite was fabricated by incor-porating tricalcium phosphate (TCP) microspheres and magnesium (Mg) particles homogenously at a volume fraction of 40 %. This approach aims to enhance mechanical strength, accelerate pore generation, and improve biological and antibacterial performance. Mg content was incorporated into the composite at varying values of 1, 3, and 5 vol% (referred to as PLA/TCP-1 Mg, PLA/TCP-3 Mg, and PLA/TCP-5 Mg, respectively). The compressive strength and stiffness were significantly enhanced in all composites, reaching 87.7, 85.9, and 84.1 MPa, and 2.7, 3.0, and 3.1 GPa, respectively. The degradation test indicated faster elimination of the reinforcers as the Mg content increased, resulting in accelerated pore generation to induce enhanced osseointegration. Because PLA/ TCP-3 Mg and PLA/TCP-5 Mg exhibited cracks in the PLA matrix due to rapid corrosion of Mg forming corrosion byproducts, to optimize the Mg particle content, PLA/TCP-1 Mg was selected for further evaluation. As determined by in vitro biological and antibacterial testing, PLA/TCP-1 Mg showed enhanced bioactivity with pre-osteoblast cells and exhibited antibacterial properties by suppressing bacterial colonization. Overall, the multifunctional PLA/TCP-Mg composite showed improved mechanobiological performance, making it a promising material for biodegradable orthopedic implants.

This study investigates the suppression of galvanic corrosion between copper and gold using cetyltrimethylammonium bromide (CTAB) and betaine as inhibitors. When copper is electrically connected to gold in PCB etching solutions, the substantial difference in their electrochemical potentials leads to the accelerated corrosion of copper, posing severe reliability risks. To mitigate this, we systematically investigated the galvanic corrosion inhibition properties of CTAB and betaine. Through comprehensive electrochemical analyses, it was found that the galvanic corrosion current density of copper, initially at 3.26 mA/cm2, decreased significantly to 0.251 mA/cm2 with 0.9 mM CTAB, indicating an inhibition efficiency of 92.3%. Furthermore, betaine, at a concentration of 0.1 mM, demonstrated an even higher inhibition efficiency, reducing the corrosion current to 0.03 mA/cm2, achieving a 99.1% inhibition rate. These findings provide strong evidence that CTAB and betaine are highly effective in suppressing galvanic corrosion in copper–gold systems, thereby enhancing the long-term performance and reliability of PCBs in electronic applications.

This study investigates the effects of sodium dodecyl sulfate (SDS) and polyethylene glycol (PEG) on the galvanic corrosion behavior of copper (Cu) coupled to gold (Au) in a printed circuit board (PCB) etching solution. Galvanic corrosion tests using ZRA (zero resistance ammeter) were performed to determine the optimal SDS concentration for corrosion inhibition. The corrosion current between Cu and Au decreased significantly with the addition of SDS, from 3.26 mA/cm2 to 0.248 mA/cm2 at 4 mM SDS, achieving an inhibitor efficiency (IE) of 92.3%. However, at 15 mM SDS, the corrosion current increased, and IE decreased to 80.5%. This phenomenon is attributed to the critical micelle concentration (CMC) of SDS, where surfactant molecules aggregate and reduce surface adsorption properties. Similarly, ZRA tests were conducted to analyze the effects of PEG on galvanic corrosion. The corrosion current significantly decreased with PEG addition, achieving 98.1% IE at 1 g/L and 99.5% IE at 2 g/L. Beyond this concentration, no significant change in IE was observed, indicating saturation. Potentiodynamic polarization tests were also conducted to study the individual effects of SDS and PEG on Cu and Au. The results showed that SDS effectively inhibited Cu corrosion but had a minimal impact on Au. In contrast, PEG significantly reduced the corrosion current density for both Cu and Au, with reductions of 99.5% and 95.1%, respectively.

A high-performance bifunctional Ni-Fe-Cr electrocatalyst with a coral reef-like porous structure was fabricated by facile one-step electrodeposition at a high cathodic current density of 8 A/cm2 for 30 min in an optimal electrodeposition bath containing 80 g/L CrCl3 and 1 M NH4Cl. The highly porous Ni-Fe-Cr electrocatalyst exhibits extremely low overpotential of 234 mV for oxygen evolution reaction (OER) and 13 mVRHE for hydrogen evolution reaction (HER) in 1 M KOH at a current density of 10 mA/cm2, respectively. The excellent performance of the Ni-Fe-Cr electrocatalyst can be attributed to the modulation of the electronic structure due to the incorporation of Cr enhanced performance capabilities of the porous Ni-Fe-Cr originate from the increased electrochemical active surface area (ECSA), which is 22 times larger than that of thin Ni-Fe-Cr. Moreover, the catalyst exhibits high stability towards the OER and HER in an alkaline solution for 36 h. This work offers a facile synthesis method by which to create a highly porous Ni-Fe-Cr electrocatalyst by electrodeposition and a strategy for increasing the catalytic activity by controlling the pore size.

The chemical coupling of molybdenum carbide (Mo2C) to cobalt (Co) promotes oxygen evolution reaction (OER) kinetics on the Co surface by making the surface more electrophilic. Here, to gain a deeper understanding of the effects of the surface electrophilic properties on the OER kinetics of Co and to obtain high OER activity, Fe and Ni are additionally incorporated into Co nanoparticles that are coupled with Mo2C nanoparticles (Co‐Mo2C). Considering the oxidation states of Fe (Fe3+), Co (Co2+/Co3+), and Ni (Ni2+) ions, Fe and Ni are expected to affect the electronic structure of Co in the opposite direction. Lewis acidic Fe3+ doping makes the Co surface oxide more electrophilic, promoting the formation of OER‐active CoOOH by strongly attracting hydroxide ions (OH−). Thus, the OER kinetics is facilitated on the Co surface of Fe‐doped Co‐Mo2C, resulting in a significantly lower overpotential for the OER. On the other hand, the Ni2+ doping makes the Co surface oxide less electrophilic, leading to an increase in the overpotential for the OER. Tailoring the electrophilic properties of the Co surface is presented as a key parameter in the design of a Co‐based OER catalyst for alkaline water electrolysis.

Electrochemical water splitting is one of the environmentally friendly methods to produce H-2 gas. However, the low cost-competitiveness of water electrolysis compared to other methods, including H-2 production from natural gas, is a main hurdle for its commercial use. Therefore, continuous efforts need to be put into water electrolysis systems for improving their energy efficiency, and the development of more active and durable electrocatalysts is one of the critical requirements. This study introduces a simple synthetic procedure of iridium oxide (IrOx) nanoparticles covered by thin carbon shells and the methods to modulate the oxidation states of IrOx and the thickness of carbon shells. The postheat treatment results in the transformation of metallic Ir to Ir4+ in IrOx and oxidative thinning of carbon shells. The synthesized IrOx catalysts are investigated for the electrochemical oxygen evolution reaction (OER). This study covers how the oxidation states of IrOx nanoparticles and carbon shells affect the performance and durability of the OER. Under the optimal conditions of both variables, a current density of 1 Acm(-2) is obtained at a cell voltage of 1.62 V from a single cell of proton exchange membrane water electrolysis (PEMWE).

Multimodal cancer treatment that combines anticancer drug delivery with other therapeutic strategies, such as photothermal therapy, has shown enormous potential for biomedical applications. However, traditional nano-scale photothermal conversion agents require complicated synthesis processes and lack biosafety, detectability, and mechanical reinforcement ability in the hyperthermia platform. Here, we engineered near-infrared laser (NIR)-responsive bullets as multifunctional nanodrug platforms via a three-dimensional (3D) printing process as an image-guided versatile chemo-photothermal cancer treatment platform. This customizable platform not only serves as a container for anticancer nanodrugs but also possesses excellent radiopacity and high photothermal conversion efficiency, merging on-demand anticancer nanodrug release and hyperthermia effect. Benefiting from the combined chemo-photothermal therapy, the 3D-printed platform showed enhanced cytotoxicity to cancer cells in vitro. Furthermore, in vivo results confirmed effective on-demand nanodrug release and synergistic inhibition of tumor growth upon NIR laser irradiation. 3D-printed NIR-responsive bullets can synergistically enhance anticancer efficiency while evading potential clinical application risks, offering great potential for multimodal cancer therapies.

Chronic wounds in diabetic patients are challenging because their prolonged inflammation makes healing difficult, thus burdening patients, society, and health care systems. Customized dressing materials are needed to effectively treat such wounds that vary in shape and depth. The continuous development of 3D‐printing technology along with artificial intelligence has increased the precision, versatility, and compatibility of various materials, thus providing the considerable potential to meet the abovementioned needs. Herein, functional 3D‐printing inks comprising DNA from salmon sperm and DNA‐induced biosilica inspired by marine sponges, are developed for the machine learning‐based 3D‐printing of wound dressings. The DNA and biomineralized silica are incorporated into hydrogel inks in a fast, facile manner. The 3D‐printed wound dressing thus generates provided appropriate porosity, characterized by effective exudate and blood absorption at wound sites, and mechanical tunability indicated by good shape fidelity and printability during optimized 3D printing. Moreover, the DNA and biomineralized silica act as nanotherapeutics, enhancing the biological activity of the dressings in terms of reactive oxygen species scavenging, angiogenesis, and anti‐inflammation activity, thereby accelerating acute and diabetic wound healing. These bioinspired 3D‐printed hydrogels produce using a DNA‐induced biomineralization strategy are an excellent functional platform for clinical applications in acute and chronic wound repair.

Chronic wounds in diabetic patients are challenging because their prolonged inflammation makes healing difficult, thus burdening patients, society, and health care systems. Customized dressing materials are needed to effectively treat such wounds that vary in shape and depth. The continuous development of 3D-printing technology along with artificial intelligence has increased the precision, versatility, and compatibility of various materials, thus providing the considerable potential to meet the abovementioned needs. Herein, functional 3D-printing inks comprising DNA from salmon sperm and DNA-induced biosilica inspired by marine sponges, are developed for the machine learning-based 3D-printing of wound dressings. The DNA and biomineralized silica are incorporated into hydrogel inks in a fast, facile manner. The 3D-printed wound dressing thus generates provided appropriate porosity, characterized by effective exudate and blood absorption at wound sites, and mechanical tunability indicated by good shape fidelity and printability during optimized 3D printing. Moreover, the DNA and biomineralized silica act as nanotherapeutics, enhancing the biological activity of the dressings in terms of reactive oxygen species scavenging, angiogenesis, and anti-inflammation activity, thereby accelerating acute and diabetic wound healing. These bioinspired 3D-printed hydrogels produce using a DNA-induced biomineralization strategy are an excellent functional platform for clinical applications in acute and chronic wound repair.

Anode-free Li-metal batteries have been reported to maximize the volumetric energy density in the cell by excluding the thick anode component while taking advantage of the high energy benefit of Li-metal anode. Nevertheless, irregular Li dendrite growth and unstable surface reactions impede the practical application of anode-free Li-metal batteries. Herein, we report a "Li-dendrite cage" for a promising anode-free Li-metal battery configuration employing a three-dimensionally (3-D) interconnected porous Cu foam electrode synthesized by a facile and versatile electrodeposition method. The numerous pores within the electrode serve as "cages" to accommodate Li dendrites for Li deposition, consequently suppressing the vertical growth of Li and alleviating the volume change of the cell during cycling. The 3-D interconnected porous Cu foam electrode exhibits facile charge transfer, lower nucleation overpotential, and reduced polarization compared to conventional Cu foil. We also investigate the Li plating/stripping behaviors and morphology evolution on the unique 3-D interconnected porous Cu foam electrode by cross-sectional observations and ex-situ characterizations. This work provides a novel strategy for rationally designing porous electrodes to achieve stable and high performance of anode-free Li-metal batteries.

Hydrogen generation through the hydrolysis of aluminum alloys has attracted significant attention because it generates hydrogen directly from alkaline water without the need for hydrogen storage technology. The hydrogen generation rate from the hydrolysis of aluminum in alkaline water is linearly proportional to its corrosion rate. To accelerate the corrosion rate of the aluminum alloy, we designed Al-Ni alloys by continuously precipitating an electrochemically noble Al3Ni phase along the grain boundaries. The Al-0.5~1 wt.% Ni alloys showed an excellent hydrogen generation rate of 16.6 mL/cm2·min, which is about 6.4 times faster than that of pure Al (2.58 mL/cm2·min). This excellent performance was achieved through the synergistic effects of galvanic and intergranular corrosion on the hydrolysis of Al. By raising the solution temperature to 50 °C, the optimal rate of hydrogen generation of Al-1 wt.% Ni in 10 wt.% NaOH solutions at 30 °C can be further increased to 54.5 mL/cm2·min.

Developing next-generation thermal-neutron-shielding and -absorbing materials for the safe storage and transportation of spent nuclear fuel is a topic of active research in academia. Gadolinium (Gd) boasts superior neutron absorption capacity compared with other nuclei. Consequently, it has garnered significant attention as a potential replacement for boron in spent nuclear fuel (SNF) applications. In this study, the austenitic stainless steels 304 and 316 and the duplex stainless steel 5A were reinforced with 2 wt.% of gadolinium to explore their thermal-neutron-absorbing efficiency. Their properties were then compared with commercial-grade borated stainless steel, as per ASTM standard A887. After the inclusion of Gd, both the yield strength and ultimate tensile strength of the alloys slightly increased, which was attributed to the evenly distributed Gd intermetallics within the matrix. However, the elongation rate was reduced. The Charpy impact absorption energy also decreased. The influence of the Gd intermetallic was further explored by examining the fractography. While the corrosion resistance of the alloy slightly diminished after the addition of Gd, its neutron absorption capacity demonstrated superior performance, especially when the Gd content was equivalent to that of boron. Although most properties of the experimental alloy deteriorated after the Gd addition, they still outperformed commercial borated stainless steel, suggesting that this alloy might be a promising candidate for SNF applications.

In developing anion exchange membrane fuel cells (AEMFCs), the sluggish hydrogen oxidation reaction (HOR) under alkaline condition is one of the major challenges to be overcome. A screening process using the simple electrodeposition method suggests Ni-29Mo as the most promising composition among the prepared Ni-M (M= Co, Fe, Zn, Cr, Mo, W) and Ni-xMo (x = 22 similar to 33 at%) samples. Experimental analyses and theoretical computations demonstrate that the Ni-29Mo is composed of metallic nickel and molybdenum oxide (Ni-MoOx) domains and the hydrogen adsorption energy on metallic Ni is tailored in the presence of MoO2 towards the optimal value. The Ni-MoOx composite catalyst shows a superior HOR activity (1.12 mA/cm(2) @ 20 mV(RHE)), outperforming carbon supported platinum (Pt/C, 1.01 mA/cm(2) @ 20 mV(RHE)), the best HOR catalyst. An AEMFC fabricated using Ni-29Mo nanoparticles as an anode catalyst exhibits excellent performance, approximately half of the Pt/C counterpart cell, demonstrating practical applicability of the catalyst.

Biodegradability, bone-healing rate, and prevention of bacterial infection are critical factors for orthopedic implants. Polylactic acid (PLA) is a good candidate biodegradable material; however, it has insufficient mechanical strength and bioactivity for orthopedic implants. Magnesium (Mg), has good bioactivity, biodegradability, and sufficient mechanical properties, similar to that of bone. Moreover, Mg has an inherent antibacterial property via a photothermal effect, which generates localized heat, thus preventing bacterial infection. Therefore, Mg is a good candidate material for PLA composites, to improve their mechanical and biological performance and add an antibacterial property. Herein, we fabricated an antibacterial PLA/Mg composite for enhanced mechanical and biological performance with an antibacterial property for application as biodegradable orthopedic implants. The composite was fabricated with 15 and 30 vol% of Mg homogeneously dispersed in PLA without the generation of a defect using a high-shear mixer. The composites exhibited an enhanced compressive strength of 107.3 and 93.2 MPa, and stiffness of 2.3 and 2.5 GPa, respectively, compared with those of pure PLA which were 68.8 MPa and 1.6 GPa, respectively. Moreover, the PLA/Mg composite at 15 vol% Mg exhibited significant improvement of biological performance in terms of enhanced initial cell attachment and cell proliferation, whereas the composite at 30 vol% Mg showed deteriorated cell proliferation and differentiation because of the rapid degradation of the Mg particles. In turn, the PLA/Mg composites exerted an antibacterial effect based on the inherent antibacterial property of Mg as well as the photothermal effect induced by near-infrared (NIR) treatment, which can minimize infection after implantation surgery. Therefore, antibacterial PLA/Mg composites with enhanced mechanical and biological performance may be a candidate material with great potential for biodegradable orthopedic implants.

Porous titanium（Ti） scaffolds have been extensively utilized as bone substitute scaffolds due to their superior biocompatibility and excellent mechanical properties. However, naturally formed TiO2 on the surface limits fast osseointegration. Different biomolecules have been widely utilized to overcome this issue; however, homogeneous porous Ti scaffolds could not simultaneously deliver multiple biomolecules that have different release behaviors. In this study, functionally graded porous Ti scaffolds（FGPTs） with dense inner and porous outer parts were fabricated using a two-body combination and densification procedure. FGPTs with growth factor（BMP-2） and antibiotics（TCH） exhibited suitable mechanical properties as bone substituting material and presented good structural stability. The release of BMP-2 was considerably prolonged, whereas the release of TCH was comparable to that of homogenous porous titanium scaffolds（control group）. The osteogenic differentiation obtained using FGPTs was maintained due to the prolonged release of BMP-2. The antimicrobial properties of these scaffolds were verified using S. aureus in terms of prior release time. In addition, various candidates for graded porous Ti scaffolds with altered pore characteristics were presented.

The kinetic-sluggish oxygen evolution reaction (OER) is the main obstacle in electrocatalytic water splitting for sustainable production of hydrogen energy. Efficient water electrolysis can be ensured by lowering the overpotential of the OER by developing highly active catalysts. In this study, a controlled electrophoretic deposition strategy was used to develop a binder-free spinel oxide nanoparticle-coated Ni foam as an efficient electrocatalyst for water oxidation. Oxygen evolution was successfully promoted using the CoFe2O4 catalyst, and it was optimized by modulating the electrophoretic parameters. When optimized, CoFe2O4 nanoparticles presented more active catalytic sites, superior charge transfer, increased ion diffusion, and favorable reaction kinetics, which led to a small overpotential of 287 mV for a current density of 10 mA cm-2, with a small Tafel slope of 43 mV dec-1. Moreover, the CoFe2O4 nanoparticle electrode exhibited considerable long-term stability over 100 h without detectable activity loss. The results demonstrate promising potential for large-scale water splitting using Earth-abundant oxide materials via a simple and cheap fabrication process.

Aluminum, used as a material for heat exchangers in air conditioners, often has problems of leakage of refrigerant on the Al surface due to corrosion. The problems originate from pitting corrosion of the Al in an external environment. To understand corrosion problems, it is necessary to study the corrosion behavior of Al in various environments. In this study, the effects of environmental factors on the corrosion behavior of Al were studied by the surface analysis and electrochemical testing in 3.5 wt% NaCl solutions, with changes of dissolved oxygen, temperature, and concentration of Cl- and S ions. Among the external environmental factors, the presence of oxygen and the increase of Cl- ion concentration do not significantly affect the corrosion potential of Al, leading to an increase of only 1.1 and 6 times, respectively. There was a significant decrease in the corrosion resistance of Al, approximately 40 and 800 times, respectively, with the increase of concentration of S and temperature.

One of the biggest challenges of nuclear industries is to fabricate safe, stable and efficient materials for the storage and transportation of spent nuclear fuels (SNFs), these materials are known as neutron shielding and absorbing materials. Recently, Gd has received much attention as a neutron absorbing material in SNF applications owing to its high neutron absorption capability. Herein, we propose novel Fe-Gd alloys as binary alloys and master alloys for potential materials in nuclear applications. Fe-Gd alloys with 20, 55 and 80 wt% Gd were selected based on the Fe-Gd phase diagram. All fabricated Fe-Gd alloys had higher hardnesses than pure Fe due to the formed Fe-Gd phases, and the Fe-rich phase had a higher hardness than the Gd-rich phase. On the other hand, corrosion resistance of the Fe-Gd alloys decreased as the Gd content increased. Satisfactory Gd-based intermetallic dispersion and modifying effects were obtained by casting Fe and stainless-steel alloy with Fe-80Gd. The average intermetallic size in the stainless-steel alloy remarkably decreased with a decrease in the average distance between Gd-based intermetallics. Fe-Gd alloys possess requisite hardness, thermal conductivity, and corrosion resistance as well as dispersion ability of intermetallics; hence, they show potential as promising candidates for SNF applications. (c) 2020 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Cost reduction and long-term durability are crucial issues for the commercialization of polymer electrolyte membrane fuel cells. To accomplish these goals, herein, we report an electrospun iron and nitrogen codoped mesoporous carbon nanofiber (Fe-N-MCNF) for use as both a low-cost nonprecious metal catalyst and a durable support of platinum nanoparticles. Silica nanoparticles and polyvinyl acetate are used together as porogens to create mesopores. As a synergetic effect of these two types of porogens, numerous mesopores are successfully formed inside of the carbon nanofibers. The highly mesoporous structure increases the specific surface area and improves the diffusion kinetics of the reactants, leading to an increase in the effective surface area of the Fe-N-MCNFs for electrochemical reactions. Therefore, the Fe-N-MCNFs can have high oxygen reduction reaction activity alone in an acidic solution and the ability to provide a large surface area for platinum nanoparticles as a support. The platinum nanoparticles on the Fe-N-MCNFs are highly stable under an oxidative potential condition of fuel cells due to the high corrosion resistance of the graphitized carbon structure. This work demonstrates that Fe-N-MCNF can be utilized as both a low-cost catalyst and a durable support in practical fuel cell applications.

A highly active cobalt-iron-phosphorus catalyst was fabricated to generate hydrogen from the hydrolysis of NH3BH3 by facile one-step electrodeposition method. The performance of the catalyst was optimized by electrodeposition condition via controlling microstructure and composition. As the applied cathodic current density was increased from 10 to 400mA/cm(2), the particle sizes of the Co-Fe-P catalysts increased from 1 to 15 mu m. With the increase in a deposition time, the particles of the Co-Fe-P catalyst became densely agglomerated. The Co-Fe-P catalyst deposited at 50 mA/cm(2) for 5min, which had a particle size of 2 mu m, exhibited the best hydrogen generation rate of 2858 ml min(-1)g(-1)-catalyst in 1 wt% NH3BH3 solution at 30 degrees C. With an increase in the solution temperature from 10 to 60 degrees C, the hydrogen generation rate increased exponentially from 1543 to 8915 ml min(-1)g(-1)-catalyst in the 1 wt% NH3BH3 solution. The activation energy for the hydrolysis of NH3BH3 by the Co-Fe-P catalyst was calculated and found to be approximately 25 +/- 3 kJ/mol, which is comparable to those of noble metal-based catalysts. Furthermore, with an increase in the concentration of NH3BH3 from 0.5 wt% to 3 wt%, the hydrogen generation rate of the Co-Fe-P catalyst increased gradually from 1900 ml min(-1)g(-1)-catalyst to 8105 ml min(-1)g(-1)-catalyst at 30 degrees C.