Hydroxide Nanorods Research Articles

Engineering a vanillate-producing strain of Pseudomonas sp. NGC7 corresponding to aromatic compounds derived from the continuous catalytic alkaline oxidation of sulfite lignin

IntroductionLignin is a promising resource for obtaining aromatic materials, however, its heterogeneous structure poses a challenge for effective utilization. One approach to produce homogeneous aromatic materials from lignin involves the application of microbial catabolism, which is gaining attention. This current study focused on constructing a catabolic pathway in Pseudomonas sp. NGC7 to produce vanillate (VA) from aromatic compounds derived from the chemical depolymerization of sulfite lignin.ResultsAlkaline oxidation of sulfite lignin was performed using a hydroxide nanorod copper foam [Cu(OH)2/CF]-equipped flow reactor. The flow reactor operated continuously for 50 h without clogging and it yielded a sulfite lignin stream containing acetovanillone (AV), vanillin (VN), and VA as the major aromatic monomers. The catabolic pathway of Pseudomonas sp. NGC7 was optimized to maximize VA production from aromatic monomers in the sulfite lignin stream derived from this oxidation process. Pseudomonas sp. NGC7 possesses four gene sets for vanillate O-demethylase, comprising the oxygenase component (vanA) and its oxidoreductase component (vanB). Among these, the vanA4B4 gene set was identified as the key contributor to VA catabolism. To facilitate the conversion of AV to VA, AV-converting enzyme genes from Sphingobium lignivorans SYK-6 were introduced. The ΔvanA4B4 strain, harboring these AV-converting genes, produced VA from the sulfite lignin stream with 91 mol%. Further disruption of vanA1B1, vanA2B2, vanA3B3, and a vanillin reductase gene, in addition to vanA4B4, and introduction of a 5-carboxyvanillate decarboxylase gene from S. lignivorans SYK-6 to utilize 5-carboxyvanillin and 5-carboxyvanillate from the sulfite lignin stream for VA production achieved a VA yield of 103 mol%.ConclusionDeveloping methods to overcome lignin heterogeneity is essential for its use as a raw material. Consolidating continuous alkaline oxidation of lignin in a Cu(OH)2/CF-packed flow reactor and biological funneling using an engineered catabolic pathway of Pseudomonas sp. NGC7 is a promising approach to produce VA for aromatic materials synthesis. NGC7 possesses a higher adaptability to various aromatic compounds generated from the alkaline oxidation of lignin and its natural ability to grow on p-hydroxyphenyl, guaiacyl, and syringyl compounds underscores its potential as a bacterial chassis for VA production from a wide range of lignin-derived aromatic compounds.Graphical

In-situ growth of FeCo layered double hydroxide nanorods on MXene for high-performance supercapacitor electrodes

In the pursuit of clean energy solutions, supercapacitors have gained attention due to their exceptional energy storage capabilities. Layered double hydroxide (LDH), a notable material in this field, faces some challenges such as slow charge transfer speed and volumetric expansion. To tackle these issues, a novel FeCo-LDH/MXene composite was synthesized through in-situ hydrothermal growth of FeCo layered double hydroxide (FeCo-LDH) nanorods on MXene using ionic self-assembly, forming a three-dimensional (3D) composite with enhanced rate capability and cycling stability due to the synergetic coupling of MXene and LDH. The FeCo-LDH/MXene electrode significantly improves surface capacitance control performance and exhibits exceptional electrochemical performance, achieving a specific capacitance of 2058.2 F g−1 at 1 A g−1 and maintaining 1732.7 F g−1 at 10 A g−1, with 82.4 % capacity retention. Furthermore, the assembled supercapacitor delivers an energy density of 48.8 Wh kg−1 at 750 W kg−1 and 25.7 Wh kg−1 at 15000 W kg−1, demonstrating excellent rate performance, as well as 80.3 % capacitance after 5000 cycles at 2 A g−1, highlighting its durability. This advancement not only overcomes the specific capacitance challenge of MXene electrodes but also enhances the conductivity and cyclic stability of LDH, making FeCo-LDH/MXene a promising candidate for future high-performance energy storage applications.

Imprinted Fe–Ni double hydroxide nanorods with high selective protein adsorption capacity

Imprinted Fe–Ni double hydroxide nanorods with high selective protein adsorption capacity

Pro-angiogenic Terbium Hydroxide Nanorods Improve Critical Limb Ischemia in Part by Amelioration of Ischemia-Induced Endothelial Injury.

Critical limb ischemia (CLI) refers to a severe condition resulting from gradual obstruction in the supply of blood, oxygen, and nutrients to the limbs. The most promising clinical solution to CLI is therapeutic angiogenesis. This study explored the potency of pro-angiogenic terbium hydroxide nanorods (THNR) for treatment of CLI, with a major focus on their impact on ischemia-induced maladaptive alterations in endothelial cells as well as on vascularization in ischemic limbs. This study demonstrated that, in hypoxia-exposed endothelial cells, THNR improve survival and promote proliferation, migration, restoration of nitric oxide production, and regulation of vascular permeability. Based on molecular studies, these attributes of THNR can be traced to the stimulation of PI3K/AKT/eNOS signaling pathways. Besides, Wnt/GSK-3β/β-catenin signaling pathways may also play a role in the therapeutic actions of THNR. Furthermore, in the murine model of CLI, THNR administration can integrally re-establish blood perfusion with concomitant reduction of muscle damage and inflammation. Additionally, improvement of locomotor activities and motor coordination in ischemic limbs in THNR treated mice is also evident. Overall, the study demonstrates that THNR have the potential to be developed as an efficacious and cost-effective alternative clinical therapy for CLI, using a nanomedicine approach.

Transformative Dynamics: Self-Assembly of Iron Oxide Hydroxide Nanorods into Iron Oxide Microcubes for Enhanced Perfluoroalkyl Substance Remediation.

We report the controlled synthesis of iron oxide microcubes (IOMCs) through the self-assembly arrays of ferric oxide hydroxide nanorods (NRs). The formation of IOMCs involves a complex interplay of nucleation, self-assembly, and growth mechanisms influenced by time, thermal treatment, and surfactant dynamics. The self-assembly of vertically aligned NRs into IOMCs is controlled by dynamic magnetism properties and capping agents like cetyltrimethylammonium bromide (CTAB), whose concentration and temperature modulation dictate growth kinetics and structural uniformity. These controlled structural growths were obtained via a hydrothermal process at 120 °C at various intervals of 8, 16, 24, and 32 h in the presence of CTAB as the capping agent. In this hydrothermal method, the formation of vertically oriented NR arrays was observed without the presence of ligands, binders, harsh drying techniques, and solvent evaporation. The formation of the self-assembly of NRs to IOMCs is obtained with an increase in saturated magnetization to attain the most stable state. The synthesized IOMCs have a uniform size, quasi-shape, and excellent dispersion. Due to its excellent magnetic and catalytic properties, IOMCs were employed to remove the various emerging pollutants known as per- and polyfluorinated substances (PFAS). Various microscopic and spectroscopic techniques were employed for the characterization and interaction studies of IOMCs with various PFAS. The interaction between IOMCs and perfluoroalkyl substances (PFAS) was investigated, revealing strong adsorption tendencies facilitated by electrostatic interactions, as evidenced by UV-vis and FT-IR spectroscopic studies. Furthermore, the higher magnetic and positive surface charge of IOMCs is responsible for an effective remediation eliminating any secondary pollution with ease of recovery after the sorption interaction studies, thereby making it practically worthwhile.

Multifunctional iron oxide‐hydroxide based nanorods for hydrogen sulfide scavenging assisted synergistic photothermal-chemotherapy of colon cancer

The tumor microenvironment responsive multifunctional nanoplatforms with integrated diagnosis and therapy have recently received great attention in anti-cancer treatment. In this study, we developed biocompatible iron oxide-hydroxide-based nanorods (DOX-FPT NRs) for MR imaging and H2S scavenging assisted synergistic photothermal-chemotherapy of colon cancer, which is fabricated by modifying polydopamine (PDA) and transferrin (Tf) on the surface of iron oxide hydroxide (FeOOH) nanorods. The prepared DOX-FPT NRs could precisely target the colon cancer cells through transferrin ligand-receptor-mediated targeting and effectively scavenge endogenous H2S to prohibit the growth of colon cancer. Meanwhile, the considerable drug loading capability and outstanding photothermal conversion efficiency are permitted by the PDA shell modification. In addition, the H2S scavenging assisted photothermal-chemotherapy showed an excellent therapeutic effect on CT26 cells via in vitro cell test. Therefore, the prepared DOX-PFT NRs will be a promising nanoplatform to enhance the therapeutic effect of colon cancer through the treatment strategy of H2S scavenging-assisted synergistic photothermal chemotherapy.

Deoxyribonucleic acid scaffolded and encapsulated one-dimensional gadolinium(III) hydroxide nanorods for supercapacitors and oxygen evaluation reaction properties

Deoxyribonucleic acid scaffolded and encapsulated one-dimensional gadolinium(III) hydroxide nanorods for supercapacitors and oxygen evaluation reaction properties

In situ construction of core–shell structured cobalt oxide@nickel–cobalt-layered double hydroxide nanorods with abundant oxygen vacancies towards boosting electrochemical energy storage

A facile in situ “growth–conversion–oxidation” strategy is employed to fabricate a core–shell structured CoO@Ov-NiCo LDH with abundant oxygen vacancies, which significantly improves the electrochemical performance.

The Active Interface of Iron-Decorated Cobalt (Oxy)Hydroxide for Oxygen Evolution Reaction

Iron can significantly enhance the activity of Co (oxy)hydroxide. However, the nature of active sites is currently under debate for Fe-Co (oxy)hydroxide. Here, we use well-define crystalline cobalt hydroxide nanosheets and nanorods as model catalysts to investigate the role of Fe on different crystal planes. The electrochemical reactivity and morphology-dependent analysis suggest that the lateral facets of Co(OH)2 are active sites and the enhancement effect of iron incorporation only occurs on lateral facets rather than basal facets. Furthermore, by introducing tetramethylammonium cation (TMA+) as a chemical probe in KOH solution, we demonstrate the Fe species can interact strongly with the “active species” on the lateral facets and promote the improvement of OER activity. This work identifies the active site of cobalt hydroxides in the presence and absence of iron and elucidates the interaction of Fe species with “active oxygen” species on the lateral facets of cobalt hydroxide, which has a fundamental implication on the design of efficient OER catalysts.

Chitosan-coated magnetic nanorods and nanospheres: physicochemical characterizations and potential as methotrexate carriers for targeted drug delivery

Abstract Spherical magnetite nanoparticles were employed in the almost all magnetic based drug delivery studies. But as we all know the shape of employed particles is one of the major deterministic properties that can significantly affect the physicochemical and biological features of nanostructures and so can fluctuate efficiency of drug delivery. However, it is worthy of consideration that so far no study has investigated the effect of the shape of nanoparticles in drug delivery. To some extent this deficiency in publications may be due to the fact that the synthesis of other forms of magnetite nanoparticles is not as developed as spherical nanoparticles. But recent experiments paved the way for the synthesis of magnetite nanoparticles specially magnetite nanorods (MNRs). So, for the first time, in the current experiment magnetite nanospheres (MNSs) and MNRs were compared in the potential for drug delivery. Chitosan is a natural and biocompatible compound that widely employed as coating material for the fabrication of anticancer drug nano-carriers. So in the present study this carbohydrate was chosen as coating material for the magnetic nanostructures. MNSs were synthesized via a co-precipitation reaction, and MNRs were obtained from the chemical reduction of iron oxide hydroxide (FeOOH) nanorods. Both nanostructures were loaded with methotrexate (MTX), and the release of the drug was measured. The chitosan-coated MNSs (C@MNSs) were 7–18 nm in diameter, and the chitosan-coated MNRs (C@MNRs) were 5–21 nm in width and 29–108 nm in length and had a porous structure. The C@MNSs had a magnetic saturation of ∼80 emu/g, whereas that for the C@MNRs was ∼45 emu/g. The synthesized nanostructures exhibited low toxicity and were able to release the drug inside the cells. The findings of this study demonstrate the suitability of C@MNRs as an alternative to spherical nano-carriers for the efficient and contained delivery of anticancer drugs to designated target cells.

Copper doped lanthanum hydroxide nanorods as a low temperature processable hole transport material for perovskite solar cells

For efficient perovskite solar cells (PSCs), hole transport layers (HTLs) are necessary components that can suppress recombination by collecting holes and blocking electrons. Inorganic hole transport materials (HTMs) are attractive because of their ease of preparation, low production cost and high stability. Although metal oxides and halides have been developed as the HTMs, metal hydroxides have not yet been reported as the HTMs of PSCs. In this work, copper doped lanthanum hydroxide (LaxCuy(OH)3) nanorods were firstly synthesized by the hydrothermal method as a new kind of HTM for PSCs. Although the valence band edge of La(OH)3 is slightly mismatch with that of perovskite layers, Cu2+ dopants improve the energy level alignment at HTL/perovskite interfaces. As an acceptor dopant for La(OH)3, Cu2+ ions also increase the hole transport ability of LaxCuy(OH)3 HTLs. Additionally, LaxCuy(OH)3 HTLs tend to encourage the crystallization of perovskite layers. As a consequence, Cu2+ dopants lead to an increase of PCE from 11.3 % to 20.4 % for LaxCuy(OH)3 based PSCs. This promotion can be related to the reduced recombination process and the elevated charge extraction process. This work firstly applied metal hydroxide as the HTMs of PSCs, and demonstrates the regulation of these HTMs by the doping method.

Nano-tablets and rods-shaped Fe and Ni oxide/hydroxide encapsulated graphene for asymmetric supercapacitor and OER applications

Ternary hybrid electrodes have been spotlighted in the energy storage and conversion domain due to their superior physicochemical and electrochemical attributes. Yet, elevating their electrochemical properties remains a challenge. Herein, gamma‑iron oxide nano-tablets and nickel hydroxide nano-rods encapsulated graphene sheets (γ-Fe2O3@Ni(OH)2@G/NF) nanocomposite (NC) electrodes are synthesized, using PVP as a surfactant by a simple, cost-effective and low-temperature synthesis procedure for supercapacitor (SC) and OER applications. These interconnected graphene sheets with γ-Fe2O3 and Ni(OH)2 are seen to enhance the electrical conductivity of NCs, leading to outstanding supercapacitive performances. The developed NC electrode displays the highest specific capacitance (Csp) of ∼937.5 F g−1 in the alkaline electrolyte. Moreover, Dunn's investigations, revealing the surface capacitive controlled contribution (77 %@10 mV s−1), predominates in the total capacitance, thus affirming the capacitor behavior of the electrodes. Using the NC electrode, an asymmetric supercapacitor (ASC) is constructed, and exhibits a maximum Csp of ∼120.3 F g−1 with an outstanding stability performance of 87.3 % capacitance retention. Moreover, the ASC displays an energy density of 22 Wh kg−1 under a power density of 1100 W kg−1. Overall, the results demonstrate that the developed ternary-hybrid composite shows promise as a worthy electrode for future energy demands.

Application of FeOOH nanorods as a heterogeneous Fenton catalyst: The Matter of aspect ratio

Due to the growing global population and shift towards industrialized societies, water pollution and the management of wastewater are becoming significant issues. Hence, there is a need for innovative approaches to remove contaminants from effluent streams to protect the environment and human health. The Fenton's reaction is an established method for wastewater treatment, and iron oxide hydroxide (FeOOH) nanorods have immense potential as heterogeneous Fenton catalysts. The catalytic potency of nanorods is determined by their morphology, especially their length. Therefore, this study aimed to synthesize FeOOH nanorods of different mean lengths (49–101 nm) and evaluate their catalytic activity in a Fenton's reaction. Nanorods with an average length of 78 nm had the highest catalytic activity, and 87% of methyl orange was degraded over the reaction. The greater catalytic activity of these nanorods can be attributed to their larger surface area compared to the other investigated sizes. FeOOH nanorods have a porous structure; thus, their surface area is not directly related to their particle size. These outcomes indicate that the porosity and surface area play a significant role in determining the performance of heterogeneous catalysts and, as a result, must be considered to develop efficient catalysts for environmental remediation.

Open-Microcolumn Array: A Novel Approach for Enhanced Electrocatalytic Bubble Desorption in Microreactors.

High-efficiency electrocatalytic water splitting requires high intrinsic activity of catalysts and even more importantly favorable mass transfer. However, gas bubbles adhering to the surface of catalysts limit the re-expose of catalytic active sites to the electrolyte and reduce the catalytic activities. The efficient desorption of bubbles can be facilitated by a hierarchical multiscale structure of the electrode surface. Herein, we report an opened periodic three-dimensional electrode composed of iron (Fe)-cobalt (Co)-nickel (Ni) (oxy)hydroxide nanorods (NRs) grown in situ on a high aspect ratio nickel microcolumn array (NCA) for electrocatalytic water splitting. Compared with the flat nickel plate, the NCA not only increases the surface area for catalyst loading but also improves the wettability of the electrolyte on the electrode surface, exhibiting superhydrophilicity/superaerophobicity (the electrolyte and the bubble contact angles were about ∼0 and 163°, respectively), which accelerates the bubble evolution and desorption process. The X-ray photoelectron spectroscopy indicates that the synergy of Fe-Co-Ni could enhance the ratio of Co3+/Co2+ and Ni3+/Ni2+ and promote the electrocatalytic activity. Benefiting from the microstructure design and synergistic effects, the Co4Fe0.5Ni0.5OOH-NR@NCA electrode achieves a superior OER performance with an overpotential of 199 mV at 10 mA·cm-2.

Therapeutic potentials of terbium hydroxide nanorods for amelioration of hypoxia-reperfusion injury in cardiomyocytes

Myocardial hypoxia reperfusion (H/R) injury is the paradoxical exacerbation of myocardial damage, caused by the sudden restoration of blood flow to hypoxia affected myocardium. It is a critical contributor of acute myocardial infarction, which can lead to cardiac failure. Despite the current pharmacological advancements, clinical translation of cardioprotective therapies have proven challenging. As a result, researchers are looking for alternative approaches to counter the disease. In this regard, nanotechnology, with its versatile applications in biology and medicine, can confer broad prospects for treatment of myocardial H/R injury. Herein, we attempted to explore whether a well-established pro-angiogenic nanoparticle, terbium hydroxide nanorods (THNR) can ameliorate myocardial H/R injury. For this study, in vitro H/R-injury model was established in rat cardiomyocytes (H9c2 cells). Our investigations demonstrated that THNR enhance cardiomyocyte survival against H/R-induced cell death. This pro-survival effect of THNR is associated with reduction of oxidative stress, lipid peroxidation, calcium overload, restoration of cytoskeletal integrity and mitochondrial membrane potential as well as augmentation of cellular anti-oxidant enzymes such as glutathione-s-transferase (GST) and superoxide dismutase (SOD) to counter H/R injury. Molecular analysis revealed that the above observations are traceable to the predominant activation of PI3K-AKT-mTOR and ERK-MEK signalling pathways by THNR. Concurrently, THNR also exhibit apoptosis inhibitory effects mainly by suppression of pro-apoptotic proteins like Cytochrome C, Caspase 3, Bax and p53 with simultaneous restoration of anti-apoptotic protein, Bcl-2 and Survivin. Thus, considering the above attributes, we firmly believe that THNR have the potential to be developed as an alternative approach for amelioration of H/R injury in cardiomyocytes.

Support Effects on Nickel Hydroxide and Oxide Nanorods Supported Au Nanoparticles for CO Oxidation

Support Effects on Nickel Hydroxide and Oxide Nanorods Supported Au Nanoparticles for CO Oxidation

Flexible aqueous supercapacitors with excellent cycling performance and high-energy density based on mesocrystalline NiCo-LDHs.

Flexible aqueous supercapacitors are promising candidates as safe power sources for wearable electronic devices (WEDs). However, the absence of advanced electrode materials with high structural stability has become the most critical factor hindering the development, which is closely related to the poor interface combination between the active substances and flexible collectors. Herein, a unique rigid layered double hydroxide (LDH) nanorod array with the mesocrystalline feature is created using the NiO-Ni layer as the inducer by the electrodeposition strategy. Differing from the traditional NiCo-LDH nanosheets directly grown on a carbon cloth, an elaborately designed NiO-Ni buffer can simultaneously and effectively improve the bidirectional combination with active substances and collectors, also the mesocrystalline LDH showed enhanced intrinsic stability through the reinforcing effect of grain boundaries. Benefiting from these, the assembled supercapacitor exhibited pre-eminent cycle stability (increased from 64% of the initial capacity after 10 000 cycles to no significant attenuation after 50 000 cycles) and ultrahigh energy density. When it was used as a flexible device, a remarkable energy density of 70.4 W h kg-1 could be harvested and processed with high flexibility in the bending state and good temperature adaptability. This study provides an excellent design strategy for the development of next-generation flexible supercapacitors with the goal of better comprehensive performances.

Enhanced wear resistance while maintaining transparency of epoxy resin coatings filled with novel one-dimensional magnesium borate hydroxide nanorods

Wear resistance and transparency are critical properties of polymer coatings. In this study, a novel nanocoating filler composed of one-dimensional inorganic magnesium borate hydroxide (MBH) nanorods was used to improve the wear resistance and transparency of epoxy resin (EP) coatings. After successfully synthesizing MBH nanorods, different amounts were added to EP coatings to prepare EP/MBH nanocomposites, denoted as ExMBH (x = 1, 5, and 10 wt% MBH). The transparency and wear resistance of the neat and MBH-filled EP coatings were estimated using optical transmittance and nanoscratch testing, respectively. The results indicate that E10MBH displays a transmittance of more than 85 % in the visible region and a low value in the UV region, resulting from the similar refractive indices of the MBH filler and EP. Additionally, the scratch recovery index and scratch hardness increase by 53 % and 22 %, respectively, while the plastic deformation energy decreases by 67 % compared to that of the neat EP coating. The E10MBH nanocoating presents excellent wear resistance due to the formation of a solid three-dimensional network structure between EP and MBH. This paper demonstrates an effective strategy for designing inorganic nanofillers to improve the mechanical durability and optical properties of EP nanocoatings.

Limpet teeth microstructure unites auxeticity with extreme strength and high stiffness.

Materials displaying negative Poisson's ratio, referred to as auxeticity, have been found in nature and created in engineering through various structural mechanisms. However, uniting auxeticity with high strength and high stiffness has been challenging. Here, combining in situ nanomechanical testing with microstructure-based modeling, we show that the leading part of limpet teeth successfully achieves this combination of properties through a unique microstructure consisting of an amorphous hydrated silica matrix embedded with bundles of single-crystal iron oxide hydroxide nanorods arranged in a pseudo-cholesteric pattern. During deformation, this microstructure allows local coordinated displacement and rotation of the nanorods, enabling auxetic behavior while maintaining one of the highest strengths among natural materials. These findings lay a foundation for designing biomimetic auxetic materials with extreme strength and high stiffness.

A High‐Efficiency MRI Contrast Agent as well as a Tumor Therapeutic Agent

AbstractInorganic/polymercore/shell nanoparticles (NPs) for theranostics have always attracted research interest due to their flexible composition and facile synthesis. Here, core/shell NPs are prepared with gadolinium hydroxide nanorods cores and Mn ion‐doped polydopamine shells. After PEG modification, the relaxation rate of Gd(OH)3@MnPDA‐PEG NRs achieved 35 s−1mm−1. The characterization results indicate that the predoping Mn ions obviously promote the effect of MRI compared with the nanorods without or with postdoping Mn ions, and the predoping method can effectively control the actual doping account of metal ions. Considering the toxicity, dopamine and manganese in molar ratio of 8:1 is finally chosen. Gd(OH)3@MnPDA‐PEG nanorods are conducted in vivo and in vitro imaging and therapeutic experiments. The results show that the nanorods has low biological toxicity, excellent magnetic resonance imaging effects, clear photoacoustic imaging, and photothermal therapy effects.