Transition-metal Nanomaterials Research Articles

Ultrafine Fe(OH)3 nanoparticles formation via oxidation-mediated strategies towards remarkable flame-retardant and smoke-suppressant performances

Transition metal nanomaterials are widely applied as flame retardants in materials. Herein, an oxidation-mediated strategy was developed for temporally controlling the in situ growth of Fe(OH)3 nanoparticles on wool/nylon (W/N) fabrics. The formed particles exhibit homogeneous dispersion on the surface of W/N fabrics, with an average particle diameter of about 60 nm. These Fe(OH)3 nanoparticles can simultaneously enhance both the flame retardancy (the limiting oxygen index increased by 18.8 % and passed the UL-94 burning test of V-0 rating) and mechanical performance (the tensile strength increased by 9.13 %) of the W/N fabrics. Meanwhile, the obtained W/N fabrics exhibit remarkable smoke-suppressant properties, demonstrating a reduction of 76.4 % and 65.5 % in smoke production rate and total smoke production, respectively, compared to the pure W/N fabrics. Furthermore, the prepared W/N fabrics exhibit good durability. This innovative strategy may be also extended for synthesizing other nanomaterials and pave a new path to develop high-performance flame-retardant materials.

Recent Progress in Transition Metal Dichalcogenides for Electrochemical Biomolecular Detection.

Advances in the field of nanobiotechnology are largely due to discoveries in the field of materials. Recent developments in the field of electrochemical biosensors based on transition metal nanomaterials as transducer elements have been beneficial as they possess various functionalities that increase surface area and provide well-defined active sites to accommodate elements for rapid detection of biomolecules. In recent years, transition metal dichalcogenides (TMDs) have become the focus of interest in various applications due to their considerable physical, chemical, electronic, and optical properties. It is worth noting that their unique properties can be modulated by defect engineering and morphology control. The resulting multifunctional TMD surfaces have been explored as potential capture probes for the rapid and selective detection of biomolecules. In this review, our primary focus is to delve into the synthesis, properties, design, and development of electrochemical biosensors that are based on transition metal dichalcogenides (TMDs) for the detection of biomolecules. We aim to explore the potential of TMD-based electrochemical biosensors, identify the challenges that need to be overcome, and highlight the opportunities for further future development.

Integrated Cu–Au stereo microelectrode arrays and microfluidic channels for the electrochemical detection of glucose

Noble and transition metal nanomaterials are widely used in glucose sensing. However, the fabrication of these sensors still suffers from complex nanomaterial synthesis process and unstable nanomaterial loading on sensing surfaces. Herein, a Cu–Au bimetallic microelectrode array was prepared via local electrochemical deposition and electrochemical reduction without the need for templates and additional nanomaterial preparation processes. Based on the COMSOL computational fluid study, the obtained microelectrode arrays combined with microfluidic channels allow the continuous and rapid detection of glucose. Large number of active sites on the surface of 3D nano-arrays contributes to excellent sensing performance for glucose, with good linear detection ranges in 10 µM to 4 × 102 µM and 4 × 102 µM to 4 × 105 µM, and a low detection limit of 284 nM. The feasibility of sensor in real sample was verified by detecting glucose in beverages with good recoveries ranging from 95.50% to 104.31%.

Recent progress on mixed transition metal nanomaterials based on metal–organic frameworks for energy-related applications

Versatile types of MOF-derived mixed transition metal nanomaterials are summarized in terms of synthetic routes. The applications of those materials in energy storage and conversion, including LIBs, SCs, ORR, OER and HER are discussed.

Polycyclodextrin as a linker for nanomedicine fabrication and synergistic anticancer application

Polycyclodextrin (denoted PCD) composed of cyclodextrin monomer units and 1,3-diethoxypropan-2-ol containing many hydroxyl groups with lone pairs of electrons, easily coordinated with transition metals with empty orbitals. The CD unit can also provide host-guest binding sites for functional molecules. This article utilizes this feature of PCD for the first time as a “linker” to combine transition metal nanomaterials with synergistic functional molecules. We synthesized PCD with 50% CD monomer by epichlorohydrin cross-linking method. Utilizing the coordination effect of the hydroxyl group in PCD and the iron ion in photothermal nanoparticles (PB-Yb), the PCD is coated on its surface; simultaneously, CD in PCD can form a host-guest complex with adamantane-modified zinc phthalocyanine (Pc) photosensitizer. Using PCD as a “linker”, PB-Yb and Pc (denoted PYPP) were combined to improve the solubility of PB-Yb, reduce the aggregation degree of Pc to increase their activity, and achieve photothermal and photodynamic synergistic tumor therapy.

Oxygen Vacancy‐rich Ni/NiO@NC Nanosheets with Schottky Heterointerface for Efficient Urea Oxidation Reaction

H2 production via electrocatalytic water splitting is greatly hindered by the sluggish oxygen evolution reaction (OER). The urea oxidation reaction (UOR) draws specific attention not only because of its lower theoretical voltage of 0.37 V compared with OER (1.23 V), but also for treating sewage water. Herein, Ni/NiO nanosheets with an ultrathin N-doped C layer containing a Schottky Ni and NiO heterointerface is constructed. Because of the self-driven charge redistribution at the heterointerface, janus charge domains are successfully created to drive the cleavage of urea molecules. Meanwhile, the synergistic effect between N-doped C and Ni/NiO restrains the deactivation of active sites in alkaline solution. The catalyst displays 1.35 V for UOR at 10 mA/cm2 , 0.27 V lower than that of OER. The final potential increase is only 2 mV after long-term stability test of 12 h for UOR, much smaller than the uncoated sample (38 mV). The present work shows that C-coated transition metal nanomaterials with oxygen vacancies and a Schottky heterointerface are promising candidates for simultaneously boosting UOR with both high activity and long-term stability.

Strongly coupled iron selenides-nitrogen-bond as an electronic transport bridge for enhanced synergistic oxygen electrocatalysis in rechargeable zinc-O2 batteries

Hybrid of transition-nitrogen-doped carbon (M-NC) and transition metal nanomaterials into one single catalyst has been considered as the most promising strategy for constructing bifunctional oxygen reduction and evolution reaction (ORR/OER) catalysts. However, the direct evidence of bridged-bond between ORR and OER catalyst which is crucial for enhancing the electrocatalytic performance, has never been confirmed in the literature. In this manuscript, we exploited a new class of strongly coupled Fe2NiSe4@Fe-NC hybrid material, in which the Fe2NiSe4 nanocubes strongly coupled to the Fe-NC through the selenium-graphitic-nitrogen bond (Se-GNG). Additional characterizations and DFT calculations have confirmed that the Se-GNG bond can act as a bridge to deliver the electrons from Fe and Ni to the graphitic-N (Quaternary-N), which is beneficial to enhance both the ORR/OER activity and durability. Due to this strong electronic interaction, this novel hybrid Fe2NiSe4@Fe-NC electrocatalyst reveals superior performance and durable operation without chemical instability towards both ORR/OER.

Facile Non-Enzymatic Electrochemical Sensing for Glucose Based on Cu2O-BSA Nanoparticles Modified GCE.

Transition-metal nanomaterials are very important to non-enzymatic glucose sensing because of their excellent electrocatalytic ability, good selectivity, the fact that they are not easily interfered with by chloride ion (Cl−), and low cost. However, the linear detection range needs to be expanded. In this paper, Cu2O–bovine serum albumin (BSA) core-shell nanoparticles (NPs) were synthesized for the first time in air at room temperature by a facile and green route. The structure and morphology of Cu2O–BSA NPs were characterized. The as-prepared Cu2O–BSA NPs were used to modify the glassy carbon electrode (GCE) in a Nafion matrix. By using cyclic voltammetry (CV), the influence from scanning speed, concentration of NaOH, and load of Cu2O–BSA NPs for the modified electrodes was probed. Cu2O–BSA NPs showed direct electrocatalytic activity for the oxidation of glucose in 50 mM NaOH solution at 0.6 V. The chronoamperometry result showed this constructing sensor in the detection of glucose with a lowest detection limit of 0.4 μM, a linear detection range up to 10 mM, a high sensitivity of 1144.81 μAmM−1cm−2 and reliable anti-interference property to Cl−, uric acid (UA), ascorbic acid (AA), and acetaminophen (AP). Cu2O–BSA NPs are promising nanostructures for the fabrication of non-enzymatic glucose electrochemical sensing devices.

Low-temperature solid-state reduction approach to highly reduced titanium oxide nanocrystals

Considerable attention has been paid to reduced transition metal nanomaterials because they exhibit attractive properties for practical applications in fuel cells, memory or thermoelectric devices, and photocatalysts. In particular, a series of oxygen-nonstoichiometric titanium oxides has advantages such as abundance of the elements, non-toxicity, corrosion resistance, and high electrical conductivity. However, the control of nanostructures is not straightforward because a high-temperature reductive condition is required for the synthesis of highly reduced metal oxides. Recently, it has been demonstrated that the novel low-temperature reduction technique can afford highly reduced titania nanoparticles with different particle sizes ranging from 20 to 300 nm diameter. This review article is focused on the synthesis of corundum-type Ti2O3 nanoparticles, the reaction mechanism, and the correlation between structure and physical properties.

Recent advances in emerging 2D nanomaterials for biosensing and bioimaging applications

Abstract The great success of graphene throws new light on discovering more two-dimensional (2D) layered nanomaterials that stem from atomically thin 2D sheets. Compared with a single element of graphene, emerging graphene-like 2D materials composed of multiple elements that possess more versatility, greater flexibility and better functionality with a wide range of potential applications. In this review, we provide insights into the rapidly emerging 2D materials and their biosensing and bioimaging applications in recent three years, including 2D transition metal nanomaterials, graphitic nitride materials, black phosphorus, and emerging 2D organic polymers. We first briefly highlight their unique 2D morphology and physicochemical properties and then focus on their recent applications in electrochemical biosensing, optical biosensing and bioimaging. The challenges and some thoughts on future perspectives in this field are also addressed.