Thin metal nanostructures: synthesis, properties and applications

Recent advances of doping strategy for boosting the electrocatalytic performance of two-dimensional noble metal nanosheets

Benefiting from the ultrahigh specific surface areas, massive exposed surface atoms, and highly tunable microstructures, the two-dimensional (2D) noble metal nanosheets (NSs) have presented promising performance for various electrocatalytic reactions. Nevertheless, the heteroatom doping strategy, and in particular, the electronic structure tuning mechanisms of the 2D noble metal catalysts (NMCs) yet remain ambiguous. Herein, we first review several effective strategies for modulating the electrocatalytic performance of 2D NMCs. Then, the electronic tuning effect of hetero-dopants for boosting the electrocatalytic properties of 2D NMCs is systematically discussed. Finally, we put forward current challenges in the field of 2D NMCs, and propose possible solutions, particularly from the perspective of the evolution of electron microscopy. This review attempts to establish an intrinsic correlation between the electronic structures and the catalytic properties, so as to provide a guideline for designing high-performance electrocatalysts.

Real-time imaging reveal anisotropic dissolution behaviors of silver nanorods

The morphology and size control of anisotropic nanocrystals are critical for tuning shape-dependent physicochemical properties. Although the anisotropic dissolution process is considered to be an effective means to precisely control the size and morphology of nanocrystals, the anisotropic dissolution mechanism remains poorly understood. Here, usingin situliquid cell transmission electron microscopy, we investigate the anisotropic etching dissolution behaviors of polyvinylpyrrolidone (PVP)-stabilized Ag nanorods in NaCl solution. Results show that etching dissolution occurs only in the longitudinal direction of the nanorod at low chloride concentration (0.2 mM), whereas at high chloride concentration (1 M), the lateral and longitudinal directions of the nanorods are dissolved. First-principles calculations demonstrate that PVP is selectively adsorbed on the {100} crystal plane of silver nanorods, making the tips of nanorods the only reaction sites in the anisotropic etching process. When the chemical potential difference of the Cl-concentration is higher than the diffusion barrier (0.196 eV) of Cl-in the PVP molecule, Cl-penetrates the PVP molecular layer of {100} facets on the side of the Ag nanorods. These findings provide an in-depth insight into the anisotropic etching mechanisms and lay foundations for the controlled preparation and rational design of nanostructures.

Fabrication of silver nanostructure array patterns (SNAPs) on silicon wafer for highly sensitive and reliable SERS substrates

Metal nanostructure arrays with large amounts of nano-gaps are important for surface enhanced Raman scattering applications, though the fabrications of such nanostructures are difficult due to the complex and multiple synthetic steps. In this research, we report silver nanostructure array patterns (SNAPs) on silicon wafer, which is fabricated with semiconductor manufacturing technology, Cu2O electrochemistry deposition, and Ag In-situ oxidation-reduction growth. Benefiting from the dense and uniform distribution of Ag nanowires, the fabricated SNAPs demonstrate a very strong and uniform surface-enhanced Raman scattering (SERS) effect. The efficiency of SNAPs was investigated by using rhodamine 6G (R6G) dye as an analyte molecule. The results show that the minimum detectable concentration of R6G can reach as low as 10-11 M, and the Raman signals in the random region show good signal homogeneity with a low relative standard deviation (RSD) of 4.77 %. These results indicate that the SNAPs perform a great sensitivity and uniformity as a SERS substrate. Furthermore, we used the SNAPs substrate to detect antibiotic sulfadiazine. The main peaks in sulfadiazine Raman and vibration modes assignments were obtained and the quantitative analysis model was established by principal component analysis (PCA). The detection and application results of sulfadiazine indicate that the SNAPs substrate can be applied for trace detection of antibiotics. In addition, we have cited the application of the SNAPs substrate in anti-counterfeiting labels. These practical applications demonstrate that the fabricated SNAPs can potentially provide a way to develop low-cost SERS platforms for environmental detections, biomedicine analysis, and commodities anti-counterfeiting.

Shape control of Au nanostructures using peptides for biotechnological applications

Metallic gold (Au) nanostructures have attracted attentions in various fields of materials science and electrical science in terms of catalysts, sensing systems, photonic devices, and drug delivery systems because of their characteristic physical, chemical, and biocompatible properties. Recently, Au nanostructures with near-infrared light absorbing properties have shown potential for applications such as biological imaging and thermotherapy in biotechnological fields. However, fabrication of Au nanostructures with complex shapes often requires the use of highly biotoxic substances such as surfactants and reducing agents. Peptides are promising compounds for controlling the shape of Au nanostructures by mineralization with several advantages for this purpose. In this highlight, we focus on the shapes with respect to the fabrication of Au nanostructures using biocompatible peptides. We classify the peptides that form Au nanostructures into three broad categories: those that bind Au ions, those that reduce Au ions, and those that control the direction of Au crystal growth. Then, we briefly summarize the correlations between peptide sequences and their roles, and propose future strategies for fabricating Au nanostructures using peptides for biotechnological applications.

Electronic and photophysical properties of an atomically thin bowl-shaped beryllene encapsulated inside the cavity of [6]cycloparaphenylene (Ben@[6]CPP)

Exotic metallic nanostructures are being intensely pursued for a myriad of applications, with ultrathin membranes currently at the heart of several investigations. The objective of the present study was to systematically assess the atom-by-atom encapsulation of Be in the molecular nanoring of [6]cycloparaphenylene ([6]CPP). Further, the study aimed to scrutinize the structure, stability, and properties of the encapsulated Ben@[6]CPP systems. The outcomes clearly revealed that [6]CPP enabled the cooperative confinement of atomically thin bowl-shaped beryllene inside its circular cavity. The confinement of Be in [6]CPP generated topologically anisotropic surfaces with distinct interior and exterior charge distributions. The Ben@[6]CPP complexes could render a cationic or anionic nature to Be depending on its neighbouring environment. Thus, the systems may offer a promising opportunity for the synergistic co-adsorption of multiple reactants that are involved in multicomponent reactions. Energy decomposition analysis (EDA) elucidated that the bonding between Be and [6]CPP was partially ionic and covalent in character. The progressive encapsulation of Be atoms inside the cavity of [6]CPP led to a red-shift of the excitation wavelength to the visible region. The calculated optical absorption coefficient was higher than 104 L mol-1 cm-1, which shows promise for diverse optoelectronic applications.

Atomic coordination environment engineering of bimetallic alloy nanostructures for efficient ammonia electrosynthesis from nitrate

Electrochemical nitrate reduction reaction (NO3RR) to ammonia has been regarded as a promising strategy to balance the global nitrogen cycle. However, it still suffers from poor Faradaic efficiency (FE) and limited yield rate for ammonia production on heterogeneous electrocatalysts, especially in neutral solutions. Herein, we report one-pot synthesis of ultrathin nanosheet-assembled RuFe nanoflowers with low-coordinated Ru sites to enhance NO3RR performances in neutral electrolyte. Significantly, RuFe nanoflowers exhibit outstanding ammonia FE of 92.9% and yield rate of 38.68 mg h-1 mgcat-1 (64.47 mg h-1 mgRu-1) at -0.30 and -0.65 V (vs. reversible hydrogen electrode), respectively. Experimental studies and theoretical calculations reveal that RuFe nanoflowers with low-coordinated Ru sites are highly electroactive with an increased d-band center to guarantee efficient electron transfer, leading to low energy barriers of nitrate reduction. The demonstration of rechargeable zinc-nitrate batteries with large-specific capacity using RuFe nanoflowers indicates their great potential in next-generation electrochemical energy systems.

Hydrothermal Synthesis of a Cellular NiO Film on Carbon Paper as a Promising Way to Obtain a Hierarchically Organized Electrode for a Flexible Supercapacitor

The formation of a cellular hierarchically organized NiO film on a carbon paper substrate under hydrothermal conditions using triethanolamine as a base has been studied. The thermal behavior of the carbon paper substrate with the applied semi-product shell was studied using synchronous thermal analysis (TGA/DSC) and it was demonstrated that such modification of the material surface leads to a noticeable increase in its thermal stability. Using scanning electron microscopy (SEM), it was shown that the NiO film grown on the carbon fiber surface is characterized by a complex cellular morphology, organized by partially layered individual nanosheets of about 4-5 nm thickness and lateral dimensions up to 1-2 μm, some edges and folds of which are located vertically relative to the carbon fiber surface. The surface of the obtained material was also examined using atomic force microscopy (AFM), and the electronic work function of the oxide shell surface was evaluated using the Kelvin probe force microscopy (KPFM) method. The electrochemical parameters of the obtained flexible NiO/CP electrode were analyzed: the dependence of the specific capacitance on the current density was determined and the stability of the material during cycling was studied, which showed that the proposed approach is promising for manufacturing hierarchically organized electrodes for flexible supercapacitors.

Plate-Like Colloidal Metal Nanoparticles

The pseudo-two-dimensional (2D) morphology of plate-like metal nanoparticles makes them one of the most anisotropic, mechanistically understood, and tunable structures available. Although well-known for their superior plasmonic properties, recent progress in the 2D growth of various other materials has led to an increasingly diverse family of plate-like metal nanoparticles, giving rise to numerous appealing properties and applications. In this review, we summarize recent progress on the solution-phase growth of colloidal plate-like metal nanoparticles, including plasmonic and other metals, with an emphasis on mechanistic insights for different synthetic strategies, the crystallographic habits of different metals, and the use of nanoplates as scaffolds for the synthesis of other derivative structures. We additionally highlight representative self-assembly techniques and provide a brief overview on the attractive properties and unique versatility benefiting from the 2D morphology. Finally, we share our opinions on the existing challenges and future perspectives for plate-like metal nanomaterials.

Defect engineering of two-dimensional materials for advanced energy conversion and storage

In the global trend towards carbon neutrality, sustainable energy conversion and storage technologies are of vital significance to tackle the energy crisis and climate change. However, traditional electrode materials gradually reach their property limits. Two-dimensional (2D) materials featuring large aspect ratios and tunable surface properties exhibit tremendous potential for improving the performance of energy conversion and storage devices. To rationally control the physical and chemical properties for specific applications, defect engineering of 2D materials has been investigated extensively, and is becoming a versatile strategy to promote the electrode reaction kinetics. Simultaneously, exploring the in-depth mechanisms underlying defect action in electrode reactions is crucial to provide profound insight into structure tailoring and property optimization. In this review, we highlight the cutting-edge advances in defect engineering in 2D materials as well as their considerable effects in energy-related applications. Moreover, the confronting challenges and promising directions are discussed for the development of advanced energy conversion and storage systems.

Etching suppression as a means to Pt dendritic ultrathin nanosheets by seeded growth

2D ultrathin metal nanostructures are emerging materials displaying distinct physical and chemical properties compared to their analogues of different dimensionalities. Nanosheets of fcc metals are intriguing, as their crystal structure does not favour a 2D configuration. Thanks to their increased surface-to-volume ratios and the optimal exposure of low-coordinated sites, 2D metal nanostructures can be advantageously exploited in catalysis. Synthesis approaches to ultrathin nanosheets of pure platinum are scarce compared to other noble metals and to Pt-based alloys. Here, we present the selective synthesis of Pt ultrathin nansosheets by a simple seeded-growth method. The most crucial point in our approach is the selective synthesis of Pt seeds comprising planar defects, a main driving force for the 2D growth of metals with fcc structure. Defect engineering is employed here, not in order to disintegrate, but for conserving the defect comprising seeds. This is achieved by in situ elimination of the principal etching agent, chloride, which is present in the PtCl₂ precursor. As a result of etching suppression, twinned nuclei, that are selectively formed during the early stage of nucleation, survive and grow to multipods comprising planar defects. Using the twinned multipods as seeds for the subsequent 2D overgrowth of Pt from Pt(acac)₂ yields ultrathin dendritic nanosheets, in which the planar defects are conserved. Using phenylacetylene hydrogenation as a model reaction of selective hydrogenation, we compared the performance of Pt nanosheets to that of a commercial Pt/C catalyst. The Pt nanosheets show better stability and much higher selectivity to styrene than the commercial Pt/C catalyst for comparable activity.

Environmentally sustainable implementations of two-dimensional nanomaterials

Rapid advancement in nanotechnology has led to the development of a myriad of useful nanomaterials that have novel characteristics resulting from their small size and engineered properties. In particular, two-dimensional (2D) materials have become a major focus in material science and chemistry research worldwide with substantial efforts centered on their synthesis, property characterization, and technological, and environmental applications. Environmental applications of these nanomaterials include but are not limited to adsorbents for wastewater and drinking water treatment, membranes for desalination, and coating materials for filtration. However, it is also important to address the environmental interactions and implications of these nanomaterials in order to develop strategies that minimize their environmental and public health risks. Towards this end, this review covers the most recent literature on the environmental implementations of emerging 2D nanomaterials, thereby providing insights into the future of this fast-evolving field including strategies for ensuring sustainable development of 2D nanomaterials.

PdAu Nanosheets for Visible-Light-Driven Suzuki Cross-Coupling Reactions

Combining a two-dimensional (2D) morphology and plasmonic photocatalysis represents an efficient design for light-driven organic transformations. We report a one-pot synthesis of surfactant templated PdAu nanosheets (NSs). Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) analyses show the formation of 2D PdAu structures was initiated through nanoparticle seeds dispersed in the alkyl ammonium salt surfactant which acted as a template for the growth into NSs. The PdAu NSs were used for visible-light-enhanced Suzuki cross coupling. The PdAu bimetallic NSs outperformed monometallic Pd NSs and commercial Pd/C in room-temperature Suzuki cross-coupling reactions. The high catalytic activity is attributed to a combination of the 2D morphology giving rise to plasmon-enhanced catalysis and a high density of surface atoms, the electron-rich Pd surface due to alloying, and the presence of weakly bound amines. A comparative study of surfactant-assisted NSs and CO-assisted NSs was also carried out to assess the influence of surface ligands on the catalytic and photocatalytic enhancement of NSs with similar morphology. The surfactant-assisted NSs showed substantially superior performance compared to the CO-assisted for room-temperature Suzuki coupling reactions.

Formation of Ultimate Thin 2D Crystal of Pt in the Presence of Hexamethylenetetramine

Platinum naturally crystalizes into a three-dimensional crystal due to its highly symmetrical fcc lattice, with a metallic bond which is non-directional and highly isotropic. This inherently means ultimately that 2D crystals of a few atoms thick growth are hardly available in this material. Here, we discovered that a combinative effect of formic acid reductant and hexamethylenetetramine surfactant during the reduction of their metal ions precursor can realize an ultimate thin 2D crystal growth in platinum. High-resolution transmission electron microscopy and filed-emission electron microscopy analysis have also discovered that the 2D crystal of Pt has 111 facets with a lateral dimension that can be up to more than 5 μm × 2 μm. The thickness of the 2D crystal of Pt is 1.55 nm. A mechanism for obtaining ultimate thin 2D crystal of Pt using the present approach is proposed.

Nanoscale visualization of metallic electrodeposition in a well-controlled chemical environment

Liquid phase transmission electron microscopy (TEM) provides a useful means to study a wide range of dynamics in solution with near-atomic spatial resolution and sub-microsecond temporal resolution. However, it is still a challenge to control the chemical environment (such as the flow of liquid, flow rate, and the liquid composition) in a liquid cell, and evaluate its effect on the various dynamic phenomena. In this work, we have systematically demonstrated the flow performance of anin situliquid TEM system, which is based on 'on-chip flow' driven by external pressure pumps. We studied the effects of different chemical environments in the liquid cell as well as the electrochemical potential on the deposition and dissolution behavior of Cu crystals. The results show that uniform Cu deposition can be obtained at a higher liquid flow rate (1.38μl min^-1), while at a lower liquid flow rate (0.1μl min^-1), the growth of Cu dendrites was observed. Dendrite formation could be further promoted byin situaddition of foreign ions, such as phosphates. The generality of this technique was confirmed by studying Zn electrodeposition. Our direct observations not only provide new insights into understanding the nucleation and growth but also give guidelines for the design and synthesis of desired nanostructures for specific applications. Finally, the capability of controlling the chemical environment adds another dimension to the existing liquid phase TEM technique, extending the possibilities to study a wide range of dynamic phenomena in liquid media.

Electrocatalytic Water Oxidation: An Overview With an Example of Translation From Lab to Market

Water oxidation has become very popular due to its prime role in water splitting and metal–air batteries. Thus, the development of efficient, abundant, and economical catalysts, as well as electrode design, is very demanding today. In this review, we have discussed the principles of electrocatalytic water oxidation reaction (WOR), the electrocatalyst and electrode design strategies for the most efficient results, and recent advancement in the oxygen evolution reaction (OER) catalyst design. Finally, we have discussed the use of OER in the Oxygen Maker (OM) design with the example of OM REDOX by Solaire Initiative Private Ltd. The review clearly summarizes the future directions and applications for sustainable energy utilization with the help of water splitting and the way forward to develop better cell designs with electrodes and catalysts for practical applications. We hope this review will offer a basic understanding of the OER process and WOR in general along with the standard parameters to evaluate the performance and encourage more WOR-based profound innovations to make their way from the lab to the market following the example of OM REDOX.

Recent advances in degradation of organic pollutant in aqueous solutions using bismuth based photocatalysts: A review

Today, a major concern associated with the environment is the water pollution occurred due to the introduction of variety of persistent organic pollutants and residual dyes from different sources (e.g., dye and dye intermediates industries, paper and pulp industries, textile industries, tannery and craft bleaching industries, pharmaceutical industries, etc.) into our natural water resources. Recently, advanced oxidation processes (AOPs) by photocatalyst have garnered great attention as a new frontier promising eco-friendly and sustainable wastewater treatment technology. Utilization of the photocatalytic technology efficiently is significant for cleaner environment. Bismuth based photocatalyst have aroused widespread attention as a visible light responsive photocatalyst for waste water treatment due to their non-toxicity, low cost, modifiable morphology, and outstanding optical and chemical properties. In this review, we have dealt with the research progress on bismuth-based photocatalysts for waste water treatment. However, it seems to give limitation over pristine photocatalysts such as slow migration of charge carriers, charge carrier recombination, low visible light absorption, etc., Various bismuth based photocatalyst and its modifications via doping, heterojunction, Z-scheme etc., are discussed in detail. Further, the strategies adopted to improve the photocatalytic activity of bismuth based photocatalyst to improve the waste water treatment (mostly drugs and dyes) are critically reviewed. Also, we have discussed the bacterial inactivation by bismuth based photocatalyst. Finally, the challenges and future aspects against bismuth based photocatalyst are explored for further research.

Constructing Schottky junctions via Pd nanosheets on DUT-67 surfaces to accelerate charge transfer

The separation, transfer and recombination of charge often affect the rate of photocatalytic reduction of CO₂. Schottky junctions can promote the rapid separation of space charge. Therefore, in this paper, Pd nanosheets were grown on the surface of DUT-67 by a hydrothermal method, and a Schottky junction was constructed between DUT-67 and Pd. Under the action of the Schottky junction, the CO yield of 0.3-Pd/DUT-67 reached 12.15 μmol/g/h, which was 17 times higher than that of DUT-67. Efficient charge transfer was demonstrated in photochemical experiments. The large specific surface area and the increased light utilization rate also contributed to the increase in the CO₂ reduction efficiency. In addition, the mechanism of Pd/DUT-67 photocatalytic reduction of CO₂ was proposed.

Kinetics-Controlled Synthesis of Gold-Silver Nanosheets with Abundant in-Plane Cracking and Their Trimetallic Derivatives for Plasmon-Enhanced Catalysis

Controlled synthesis of two-dimensional noble metal nanomaterials with in-plane branching morphology has been of great research interest recently, which yet achieves limited success for AuAg-based nanocrystals. Herein, we report the...

Plasmonic O2 dissociation and spillover expedite selective oxidation of primary C-H bonds

Manipulating O₂ activation via nanosynthetic chemistry is critical in many oxidation reactions central to environmental remediation and chemical synthesis. Based on a carefully designed plasmonic Ru/TiO_2−x catalyst, we first report a room-temperature O₂ dissociation and spillover mechanism that expedites the “dream reaction” of selective primary C–H bond activation. Under visible light, surface plasmons excited in the negatively charged Ru nanoparticles decay into hot electrons, triggering spontaneous O₂ dissociation to reactive atomic ˙O. Acceptor-like oxygen vacancies confined at the Ru–TiO₂ interface free Ru from oxygen-poisoning by kinetically boosting the spillover of ˙O from Ru to TiO₂. Evidenced by an exclusive isotopic O-transfer from ¹⁸O₂ to oxygenated products, ˙O displays a synergistic action with native ˙O₂⁻ on TiO₂ that oxidizes toluene and related alkyl aromatics to aromatic acids with extremely high selectivity. We believe the intelligent catalyst design for desirable O₂ activation will contribute viable routes for synthesizing industrially important organic compounds.

Room-temperature O₂ dissociation and spillover, as driven by plasmonic Ru on oxygen-deficient TiO₂, expedite the selective oxidation of primary C–H bonds in alkyl aromatics for synthesizing industrially important organic compounds.

Recent development in graphdiyne and its derivative materials for novel biomedical applications

Graphdiyne (GDY), which possess sp- and sp²-hybridized carbon and Dirac cones, offers unique physical and chemical properties, including an adjustable intrinsic bandgap, excellent charge carrier transfer efficiency, and superior conductivity compared to other carbon allotropes. These exceptional qualities of GDY and its derivatives have been successfully used in a variety of fields, including catalysis, energy, environmental protection, and biological applications. Herein, we focus on the potential application of GDY and its derivatives in the biomedical domain, including biosensing, biological protection, cancer therapy, and antibacterial agents, demonstrating how the biomimetic behavior of these materials can be a step forward in bridging the gap between nature and applications. Considering the excellent biocompatibility, solubility and selectivity of GDY and its derived materials, they have shown great potential as biosensing and bio-imaging materials. The unusual combination of properties in GDY has been used in biological applications such as "OFF-ON" DNA detection and enzymatic sensing, where GDY has a greater adsorption capacity than graphene and other 2D materials, resulting in increased sensitivity. GDY and its derivatives have also been used in cancer treatment due to their high doxorubicin (DOX) loading capacity (using-stacking) and photothermal conversion ability, and radiation protection since their initial biological use. The poor biodegradation rate of graphene demands the search for new nanomaterials. Accordingly, GDY has better biocompatibility and bio-safety than other 2D nanomaterials, especially graphene and its oxide, due to its absence of aggregation in the physiological environment. Thus, GDY-based nanomaterials have become promising candidates as bio-delivery carriers. Besides, GDY and GDY-based materials have also shown interesting applications in the fields of cell-culture, cell-growth and tissue engineering. Herein, we present a comprehensive review on the applications of GDY and its derivatives as biomedical materials, followed by their future perspectives. This review will provide an outlook for the application of graphene and its derivatives and may open up new horizons to inspire broader interests across various disciplines. Finally, the future prospects for GDY-based materials are examined for their potential biological use.

Emerging 2D Nanomaterials for Biomedical Applications

Two-dimensional (2D) nanomaterials are an emerging class of biomaterials with remarkable potential for biomedical applications. The planar topography of these nanomaterials confers unique physical, chemical, electronic and optical properties, making them attractive candidates for therapeutic delivery, biosensing, bioimaging, regenerative medicine, and additive manufacturing strategies. The high surface-to-volume ratio of 2D nanomaterials promotes enhanced interactions with biomolecules and cells. A range of 2D nanomaterials, including transition metal dichalcogenides (TMDs), layered double hydroxides (LDHs), layered silicates (nanoclays), 2D metal carbides and nitrides (MXenes), metal-organic framework (MOFs), covalent organic frameworks (COFs) and polymer nanosheets have been investigated for their potential in biomedical applications. Here, we will critically evaluate recent advances of 2D nanomaterial strategies in biomedical engineering and discuss emerging approaches and current limitations associated with these nanomaterials. Due to their unique physical, chemical, and biological properties, this new class of nanomaterials has the potential to become a platform technology in regenerative medicine and other biomedical applications.

Facile Synthesis of PdCuRu Porous Nanoplates as Highly Efficient Electrocatalysts for Hydrogen Evolution Reaction in Alkaline Medium

Ru is a key component of electrocatalysts for hydrogen evolution reaction (HER), especially in alkaline media. However, the catalytic activity and durability of Ru-based HER electrocatalysts are still far from satisfactory. Here we report a solvothermal approach for the synthesis of PdCuRu porous nanoplates with different Ru compositions by using Pd nanoplates as the seeds. The PdCuRu porous nanoplates were formed through underpotential deposition (UPD) of Cu on Pd, followed by alloying Cu with Pd through interdiffusion and galvanic replacement between Cu atoms and Ru precursor simultaneously. When evaluated as HER electrocatalysts, the PdCuRu porous nanoplates exhibited excellent catalytic activity and durability. Of them, the Pd24Cu29Ru47/C achieved the lowest overpotential (40.7 mV) and smallest Tafel slope (37.5 mV dec−1) in an alkaline solution (much better than commercial Pt/C). In addition, the Pd24Cu29Ru47/C only lost 17% of its current density during a stability test for 10 h, while commercial Pt/C had a 59.5% drop under the same conditions. We believe that the electron coupling between three metals, unique porous structure, and strong capability of Ru for water dissociation are responsible for such an enhancement in HER performance.

Differences and Similarities of Photocatalysis and Electrocatalysis in Two-Dimensional Nanomaterials: Strategies, Traps, Applications and Challenges

Photocatalysis and electrocatalysis have been essential parts of electrochemical processes for over half a century. Recent progress in the controllable synthesis of 2D nanomaterials has exhibited enhanced catalytic performance compared to bulk materials. This has led to significant interest in the exploitation of 2D nanomaterials for catalysis. There have been a variety of excellent reviews on 2D nanomaterials for catalysis, but related issues of differences and similarities between photocatalysis and electrocatalysis in 2D nanomaterials are still vacant. Here, we provide a comprehensive overview on the differences and similarities of photocatalysis and electrocatalysis in the latest 2D nanomaterials. Strategies and traps for performance enhancement of 2D nanocatalysts are highlighted, which point out the differences and similarities of series issues for photocatalysis and electrocatalysis. In addition, 2D nanocatalysts and their catalytic applications are discussed. Finally, opportunities, challenges and development directions for 2D nanocatalysts are described. The intention of this review is to inspire and direct interest in this research realm for the creation of future 2D nanomaterials for photocatalysis and electrocatalysis.

Intraband hot-electron photoluminescence of a silver nanowire-coupled gold film via high-order gap plasmons

We report a strong one-photon photoluminescence (PL) behavior of a silver nanowire directly coupled gold film. The PL peak position of the silver nanowire-coupled gold film deviates from the intrinsic interband transition of gold materials and is not sensitive to the diameter change of the silver nanowire. We attribute this strong PL behavior to the intraband transition of hot electrons dominated by high-order gap plasmons, which are excited in the ultra-small gap formed by an ultra-thin polyvinyl pyrrolidone (PVP) layer coated on the silver nanowire. The results show that the energy required for the strong PL of the heterogeneous system mainly comes from the gold film, acting as an incident energy absorber enhanced by the high-order gap plasmons, while the silver nanowire acts an efficient incident energy focusing antenna. In situ Raman scattering spectra and time-resolved PL intensity integral curves were used to record the carbonization and disappearance process of PVP. The understanding of the PL behavior of the silver nanowire directly coupled gold film proves the universality of plasmon-modulated PL theory and is also of great significance to improve the generation and utilization efficiency of hot electrons with high-order gap plasmons in the fields of catalysis and incident energy capture.

Facile Synthesis of Pd@PtM (M = Rh, Ni, Pd, Cu) Multimetallic Nanorings as Efficient Catalysts for Ethanol Oxidation Reaction

Pt-based multimetallic nanorings with a hollow structure are attractive as advanced catalysts due to their fantastic structure feature. However, the general method for the synthesis of such unique nanostructures is still lack. Here we report the synthesis of Pd@PtM (M = Rh, Ni, Pd, Cu) multimetallic nanorings by selective epitaxial growth of Pt alloyed shells on the periphery of Pd nanoplates in combination with oxidative etching of partial Pd in the interior. In situ generation of CO and benzoic acid arising from interfacial catalytic reactions between Pd nanoplates and benzaldehyde are critical to achieve high-quality Pt-based multimetallic nanorings. Specifically, the in-situ generated CO promotes the formation of Pt alloyed shells and their epitaxial growth on Pd nanoplates. In addition, the as-formed benzoic acid and residual oxygen are responsible for selective oxidative etching of partial Pd in the interior. When evaluated as electrocatalysts, the Pd@PtRh nanorings exhibit remarkably enhanced activity and stability for ethanol oxidation reaction (EOR) compared to the Pd@PtRh nanoplates and commercial Pt/C due to their hollow nanostructures.

Nonspherical Metal-Based Nanoarchitectures: Synthesis and Impact of Size, Shape, and Composition on Their Biological Activity

Metal-based nanoentities, apart from being indispensable research tools, have found extensive use in the industrial and biomedical arena. Because their biological impacts are governed by factors such as size, shape, and composition, such issues must be taken into account when these materials are incorporated into multi-component ensembles for clinical applications. The size and shape (rods, wires, sheets, tubes, and cages) of metallic nanostructures influence cell viability by virtue of their varied geometry and physicochemical interactions with mammalian cell membranes. The anisotropic properties of nonspherical metal-based nanoarchitectures render them exciting candidates for biomedical applications. Here, the size-, shape-, and composition-dependent properties of nonspherical metal-based nanoarchitectures are reviewed in the context of their potential applications in cancer diagnostics and therapeutics, as well as, in regenerative medicine. Strategies for the synthesis of nonspherical metal-based nanoarchitectures and their cytotoxicity and immunological profiles are also comprehensively appraised.

The effect of 2D tungsten disulfide nanoparticles on Lewis lung carcinoma cells in vitro

The unique physicochemical properties of modern two-dimensional (2D) nanomaterials with graphene-like structures make them promising candidates for biology and medicine purposes. In this article, we investigate the influence of the two-dimensional tungsten disulfide (2D WS₂) water suspension nanoparticles obtained by an improved mechanochemical method from powdered WS₂ on morphological and structural characteristics of Lewis lung carcinoma cells using FT-IR, Raman spectroscopy, and confocal microscopy. The characterization of the 2D WS₂ nanoparticles by different physical methods is given also. We have highlighted that 2D WS₂ does not exert cytotoxic activity in the case of 1 day incubation with tumor cells. Prolongation of the incubation period up to 2 days has caused a statistically significant (p < 0.05) concentration-dependent decrease of the number of viable cells by more than 30% with the maximum cytotoxic effect at concentrations of 2D WS₂ close to 2 μg ml⁻¹. In the Raman spectra of 2D WS₂ treated cells the bands centered at 354 cm⁻¹ and 419 cm⁻¹, which are assigned to characteristics and modes of WS₂ nanoparticles were observed. The obtained data indicate, that the cytotoxic effect of 2D WS₂ on tumor cells in the case of long-term incubation is realized particularly through the ability of 2D WS₂ to enter tumor cells and/or accumulate on their surface, which gives a rationale to conduct further studies of their antitumor efficacy in vitro and in vivo when combined with chemotherapeutic drugs.

WS₂ 2D nanoparticles show no cytotoxic and/or cytostatic effect on Lewis lung carcinoma cells after one day incubation. Only after two days incubation we registered cytotoxic effect. Cells incubated with 2D WS₂ nanoparticles have luminescence in the blue spectral region.

Revitalizing silver nanocrystals as a redox catalyst by modifying their surface with an isocyanide-based compound

Silver is an excellent catalyst for oxidation reactions such as ethylene epoxidation, but it shows limited activity toward reduction reactions. Here we report a strategy to revitalize Ag nanocrystals as a redox catalyst for the production of an aromatic azo compound by modifying their surface with an isocyanide-based compound. We also leverage in situ fingerprint spectroscopy to acquire molecular insights into the reaction mechanism by probing the vibrational modes of all chemical species at the catalytic surface with surface-enhanced Raman spectroscopy. We establish that binding of isocyanide to Ag nanocrystals makes it possible for Ag to extract the oxygen atoms from the nitro-groups of nitroaromatics and then use these atoms to oxidize isocyanide to isocyanate. Concurrently, the coupling between two adjacent deoxygenated nitroaromatic molecules leads to the formation of an aromatic azo compound.

Emerging Strategies in Stimuli-Responsive Nanocarriers as the Drug Delivery System for Enhanced Cancer Therapy

The conventional Drug Delivery System (DDS) has limitations such as leakage of the drug, toxicity to normal cells and loss of drug efficiency, while the stimuli-responsive DDS is non-toxic to cells, avoiding the leakage and degradation of the drug because of its targeted drug delivery to the pathological site. Thus nanomaterial chemistry enables - the development of smart stimuli-responsive DDS over the conventional DDS. Stimuliresponsive DDS ensures spatial or temporal, on-demand drug delivery to the targeted cancer cells. The DDS is engineered by using the organic (synthetic polymers, liposomes, peptides, aptamer, micelles, dendrimers) and inorganic (zinc oxide, gold, magnetic, quantum dots, metal oxides) materials. Principally, these nanocarriers release the drug at the targeted cells in response to external and internal stimuli such as temperature, light, ultrasound and magnetic field, pH value, redox potential (glutathione), and enzyme. The multi-stimuli responsive DDS is more promising than the single stimuli-responsive DDS in cancer therapy, and it extensively increases drug release and accumulation in the targeted cancer cells, resulting in better tumor cell ablation. In this regard, a handful of multi-stimuli responsive DDS is in clinical trials for further approval. A comprehensive review is crucial for addressing the existing knowledge about multi-stimuli responsive DDS, and hence, we summarized the emerging strategies in tailored ligand functionalized stimuli-responsive nanocarriers as the DDS for cancer therapies.

An Electrochemical Aptasensor Platform Based on Flower-Like Gold Microstructure-Modified Screen-Printed Carbon Electrode for Detection of Serpin A12 as a Type 2 Diabetes Biomarker

Purpose

In the present study, a highly sensitive and simple electrochemical (EC) aptasensor for the detection of serpin A12 as a novel biomarker of diabetes was developed on a platform where flower-like gold microstructures (FLGMs) are electrodeposited onto a disposable screen-printed carbon electrode. Meanwhile, serpin A12-specific thiolated aptamer was covalently immobilized on the FLGMs.

Methods

The electrochemical activity of a fabricated aptasensor under various conditions were examined by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Aptamer concentration, deposition time, self-assembly time, and incubation time were optimized for assay of serpin A12. The differential pulse voltammetry (DPV) was implemented for quantitative detection of serpin A12 in K₃ [Fe (CN) ₆]/K₄ [Fe (CN) ₆] solution (redox probe).

Results

The label-free aptasensor revealed a linear range of serpin A12 concentration (0.039–10 ng/mL), detection limit of 0.020 ng/mL (S/N=3), and 0.031 ng/mL in solution buffer and plasma, respectively.

Conclusion

The results indicate that this aptasensor has a high sensitivity, selectivity, stability, and acceptable reproducibility for detection of serpin A12 in diabetic patients.

Ultrathin Pd-based nanosheets: syntheses, properties and applications

Two-dimensional (2D) noble metal-based nanosheets (NSs) have received considerable interest in recent years due to their unique properties and widespread applications. Pd-based NSs, as a typical member of 2D noble metal-based NSs, have been most extensively studied. In this review, we first summarize the research progress on the synthesis of Pd-based NSs, including pure Pd NSs, Pd-based alloy NSs, Pd-based core-shell NSs and Pd-based hybrid NSs. The synthetic strategy and growth mechanism are systematically discussed. Then their properties and applications in catalysis, biotherapy, gas sensing and so on are introduced in detail. Finally, the challenges and opportunities towards the rational design and controlled synthesis of Pd-based NSs are proposed.

Recent advances in two-dimensional-material-based sensing technology toward health and environmental monitoring applications

Monitoring harmful and toxic chemicals, gases, microorganisms, and radiation has been a challenge to the scientific community for the betterment of human health and environment. Two-dimensional (2D)-material-based sensors are highly efficient and compatible with modern fabrication technology, which yield data that can be proficiently used for health and environmental monitoring. Graphene and its oxides, black phosphorus (BP), transition metal dichalcogenides (TMDCs), metal oxides, and other 2D nanomaterials have demonstrated properties that have been alluring for the manufacture of highly sensitive sensors due to their unique material properties arising from their inherent structures. This review summarizes the properties of 2D nanomaterials that can provide a platform to develop high-performance sensors. In this review, we have also discussed the advances made in the field of infrared photodetectors and electrochemical sensors and how the structural properties of 2D nanomaterials affect sensitivity and performance. Further, this review highlights 2D-nanomaterial-based electrochemical sensors that can be used to check for contaminations from heavy metals, organic/inorganic compounds, poisonous gases, pesticides, bacteria, antibiotics, etc., in water or air, which are severe risks to human wellbeing as well as the environment. Moreover, the limitations, future prospects, and challenges for the development of sensors based on 2D materials are also discussed for future advancements.

Synthesis of water-dispersible, plate-like perovskites and their core-shell nanocrystals

Shape-controlled halide perovskite nanocrystals are attractive as an emerging functional material; however, these nanocrystals are prepared using organic solvents containing alkylamines and there are few reports on the synthesis of water-dispersible halide perovskite nanocrystals. We report a simple method to prepare water-dispersible, plate-like perovskite nanocrystals by mixing a long-chain amidoamine derivative (C18AA) and potassium tetrachloropalladate (K₂PdCl₄) in water. The obtained nanocrystals have a 2D layered perovskite structure represented by the chemical formula (C18AAH₂)PdCl₄. Furthermore, because seed-mediated growth is useful for preparing shape-controlled nanocrystals, such as rods, plates, wires and cubes, we used the water-dispersible (C18AAH₂)PdCl₄ nanocrystals as seeds to grow (C18AAH₂)PdCl₄@Pt core–shell nanocrystals. The core–shell nanocrystals have rough surfaces due to the deposition of Pt on the (C18AAH₂)PdCl₄ seeds. In addition, plate-like (C18AAH₂)PdCl₄@Au core–shell nanocrystals were easily obtained using this seed-mediated growth method.

Water-dispersible, plate-like perovskite nanocrystals were prepared using a long-chain amidoamine derivative (C18AA) and perovskite@Pt or Au core–shell nanocrystals were synthesized using the plate-like perovskite nanocrystals as seeds.

Effects of a graphene substrate on the structure and properties of atomically thin metal sheets

The production and use of atomically thin metal sheets are desirable but challenging. Here, density functional theory calculations indicate that the introduction of graphene as a support can play an unexpected role in the stability and function of Rh monolayer, as a representative of single-layer metal nanosheets. The graphene stabilizes the otherwise unstable Rh monolayer by the substrate interaction that not only impedes the out-of-plane movement of the Rh atoms but also decreases the surface energy. The Rh/graphene bilayer has good mechanical properties, comparable to those of emerging 2D graphene-based materials. The interfacial stress from the substrate interaction causes surface corrugations to form on the bilayer, exhibiting a degree of consistency in the direction and the area. Discrete magnetic units, compatible with the substrate interaction, are present in the corrugated Rh sheet. The visible magnetic anisotropy and spin-splitting of polarized carrier states of the corrugated Rh sheet dominate the spin-dependent transport in the bilayer film, which can be used as a building block for ultrathin electronic/spintronic devices.

Investigating the role of reducing agents on mechanosynthesis of Au nanoparticles

The influence of reducing agents on the mechanochemical synthesis of Au nanoparticles differ significantly from analogous solution syntheses. Environmentally benign mechanochemical syntheses of metal nanoparticles therefore require dedicated studies.

Porous pyrrhotite Fe7S8 nanowire/SiOx/nitrogen-doped carbon matrix for high-performance Li-ion-battery anodes

Iron sulfides, known as attractive anode materials for rechargeable lithium-ion batteries, have been extensively studied. Nevertheless, low electrical conductivity and huge volume expansion of iron sulfides hinder its practical applications. Herein, a novel method was developed to synthesize ternary porous Fe₇S₈ nanowires/SiO_x/nitrogen-doped carbon matrix by facile hydrothermal method and subsequent sulfidation derived from bamboo leaves. The SiO_x/nitrogen-doped carbon matrix can ensure the growth of nanowires, maintain the structural stability, improve the conductivity and provide improved capacity of Fe₇S₈. The 3D matrix structure and porous properties of Fe₇S₈ nanowires effectively relieve the volume change upon the insertion/extraction of Li⁺. The Fe₇S₈/SiO_x/nitrogen-doped carbon anode exhibited a superior discharge capacity of 1060.2 mA h g^-1 at 200 mA g^-1 along with good long cycling performance of 415.8 mA h g^-1 at the 1000th cycle at 5 A g^-1. The facile strategy for preparing ternary Fe₇S₈ composites with superb LIB electrochemical performances demonstrates a great potential in electrochemical energy storage.

Enhanced Photoelectrocatalytic Reduction and Removal of Atrazine: Effect of Co-Catalyst and Cathode Potential

Photoelectrocatalytic (PEC) reduction and removal of atrazine, one typical endocrine disruptor chemical, was achieved on Pd quantum dots modified TiO₂ nanotubes (PdQDs@TiO₂NTs) under regulating potentials. Compared with that on TiO₂NTs, the PEC reduction efficiency of atrazine on PdQDs@TiO₂NTs significantly increased, mainly attributed to the reduced electron transfer resistance, longer lifetime of the photogenerated electrons and the faster electron injection from the catalyst to atrazine in the solution. Meanwhile, PdQDs could also function as cocatalyst so that the electrocatalytic activity of PdQDs@TiO₂NTs was evidently improved. Moreover, the investigation indicated that the applied potential not only played important role in accelerating the separation of photogenerated electrons and holes, but also with the increment of the cathodic potential, the PEC reduction mechanism of atrazine underwent the variation of electro-assisted photocatalysis, synergetic photoelectro-catalysis, and photoassisted electro-catalysis. A highest atrazine PEC reduction efficiency was achieved as 99.5% on PdQDs@TiO₂NTs in about 5 h under the potential of -1.3 V vs. SCE, whereas the highest synergetic effect of photo- and electro- catalysis was achieved at a lower potential of -0.9 V vs. SCE.

Plasmon-Mediated Synthesis of Periodic Arrays of Gold Nanoplates Using Substrate-Immobilized Seeds Lined with Planar Defects

The seed-mediated growth of noble metal nanostructures with planar geometries requires the use of seeds lined with parallel stacking faults so as to provide a break in symmetry in an otherwise isotropic metal. Although such seeds are now routinely synthesized using colloidal pathways, equivalent pathways have not yet been reported for the fabrication of substrate-based seeds with the same internal defect structures. The challenge is not merely to form seeds with planar defects but to do so in a deterministic manner so as to have stacking faults that only run parallel to the substrate surface while still allowing for the lithographic processes needed to regulate the placement of seeds. Here, we demonstrate substrate-imposed epitaxy as a viable synthetic control able to induce planar defects in Au seeds while simultaneously dictating nanostructure in-plane alignment and crystallographic orientation. The seeds, which are formed in periodic arrays using nanoimprint lithography in combination with a vapor-phase assembly process, are subjected to a liquid-phase plasmon-mediated synthesis that uses light as an external stimuli to drive a reaction yielding periodic arrays of hexagonal Au nanoplates. These achievements not only represent the first of their kind demonstrations but also advance the possibility of integrating wafer-based technologies with a rich and exciting nanoplate colloidal chemistry.

Nanostructuration of Thin Metal Films by Pulsed Laser Irradiations: A Review

Metal nanostructures are, nowadays, extensively used in applications such as catalysis, electronics, sensing, optoelectronics and others. These applications require the possibility to design and fabricate metal nanostructures directly on functional substrates, with specifically controlled shapes, sizes, structures and reduced costs. A promising route towards the controlled fabrication of surface-supported metal nanostructures is the processing of substrate-deposited thin metal films by fast and ultrafast pulsed lasers. In fact, the processes occurring for laser-irradiated metal films (melting, ablation, deformation) can be exploited and controlled on the nanoscale to produce metal nanostructures with the desired shape, size, and surface order. The present paper aims to overview the results concerning the use of fast and ultrafast laser-based fabrication methodologies to obtain metal nanostructures on surfaces from the processing of deposited metal films. The paper aims to focus on the correlation between the process parameter, physical parameters and the morphological/structural properties of the obtained nanostructures. We begin with a review of the basic concepts on the laser-metal films interaction to clarify the main laser, metal film, and substrate parameters governing the metal film evolution under the laser irradiation. The review then aims to provide a comprehensive schematization of some notable classes of metal nanostructures which can be fabricated and establishes general frameworks connecting the processes parameters to the characteristics of the nanostructures. To simplify the discussion, the laser types under considerations are classified into three classes on the basis of the range of the pulse duration: nanosecond-, picosecond-, femtosecond-pulsed lasers. These lasers induce different structuring mechanisms for an irradiated metal film. By discussing these mechanisms, the basic formation processes of micro- and nano-structures is illustrated and justified. A short discussion on the notable applications for the produced metal nanostructures is carried out so as to outline the strengths of the laser-based fabrication processes. Finally, the review shows the innovative contributions that can be proposed in this research field by illustrating the challenges and perspectives.

Aging amorphous/crystalline heterophase PdCu nanosheets for catalytic reactions

Phase engineering is arising as an attractive strategy to tune the properties and functionalities of nanomaterials. In particular, amorphous/crystalline heterophase nanostructures have exhibited some intriguing properties. Herein, the one-pot wet-chemical synthesis of two types of amorphous/crystalline heterophase PdCu nanosheets is reported, in which one is amorphous phase-dominant and the other one is crystalline phase-dominant. Then the aging process of the synthesized PdCu nanosheets is studied, during which their crystallinity increases, accompanied by changes in some physicochemical properties. As a proof-of-concept application, their aging effect on catalytic hydrogenation of 4-nitrostyrene is investigated. As a result, the amorphous phase-dominant nanosheets initially show excellent chemoselectivity. After aging for 14 days, their catalytic activity is higher than that of crystalline phase-dominant nanosheets. This work demonstrates the intriguing properties of heterophase nanostructures, providing a new platform for future studies on the regulation of functionalities and applications of nanomaterials by phase engineering.

Tunable 2D-gallium arsenide and graphene bandgaps in a graphene/GaAs heterostructure: an ab initio study

The bandgap behavior of 2D-GaAs and graphene have been investigated with van der Waals heterostructured into a yet unexplored graphene/GaAs bilayer, under both uniaxial stress along c axis and different planar strain distributions. The 2D-GaAs bandgap nature changes from [Formula: see text]-K indirect in isolated monolayer to [Formula: see text]-[Formula: see text] direct in graphene/GaAs bilayer. In the latter, graphene exhibits a bandgap of 5 meV. The uniaxial stress strongly affects the graphene electronic bandgap, while symmetric in-plane strain does not open the bandgap in graphene. Nevertheless, it induces remarkable changes on the GaAs bandgap-width around the Fermi level. However, when applying asymmetric in-plane strain to graphene/GaAs, the graphene sublattice symmetry is broken, and the graphene bandgap is open at the Fermi level to a maximum width of 814 meV. This value is much higher than that reported for just graphene under asymmetric strain. The [Formula: see text]-[Formula: see text] direct bandgap of GaAs remains unchanged in graphene/GaAs under different types of applied strain. The analyses of phonon dispersion and the elastic constants yield the dynamical and mechanical stability of the graphene/GaAs system, respectively. The calculated mechanical properties for bilayer heterostructure are better than those of their constituent monolayers. This finding, together with the tunable graphene bandgap not only by the strength but also by the direction of the strain, enhance the potential for strain engineering of ultrathin group-III-V electronic devices hybridized by graphene.

Corrosion Engineering To Synthesize Ultrasmall and Monodisperse Alloy Nanoparticles Stabilized in Ultrathin Cobalt (Oxy)hydroxide for Enhanced Electrocatalysis

Two-dimensional (2D) nanomaterials decorated with ultrasmall and well-alloyed bimetallic nanoparticles (NPs) have many important applications. Developing a facile and scalable 2D material/hybrid synthesis strategy is still a big challenge. Herein, a top-down corrosion strategy is developed to prepare ultrathin cobalt (oxy)hydroxide nanosheets decorated with ultrasmall (∼1.6 nm) alloy NPs. The formation of ultrathin (oxy)hydroxide nanosheets has a restrain effect to prevent the growth of small NPs into bigger ones. Thanks to the ultrathin 2D nature and strong electronic interaction between Co(OH)₂ and alloy NPs, the Pt-based binary alloy NPs are greatly stabilized by the Co(OH)₂ nanosheets and the hybrids exhibit much enhanced electrocatalytic performance for water splitting. Especially, the mass activities of the PtPd- and PtCu-decorated samples for hydrogen evolution are ∼8 times that of Pt/C. When used as both cathode and anode electrocatalysts to split water, the hybrid nanosheets outperform the commercial Pt/C-RuO₂ combination. At 10 mA cm^-2, the needed potential is only 1.53 V. This work provides us a highly controllable and scalable means to produce clean 2D nanomaterials decorated with a series of alloy NPs such as PtPd, PtCu, AuNi, and so forth.

Highly Excavated Octahedral Nanostructures Integrated from Ultrathin Mesoporous PtCu3 Nanosheets: Construction of Three-Dimensional Open Surfaces for Enhanced Electrocatalysis

Developing electrocatalysts with ultrathin nanostructures and high mesoporosity is a relevant high-priority research direction toward enhancing the performance of noble metals. Herein, mesoporous, highly excavated octahedral PtCu₃ nanostructures are prepared by a facile one-pot synthesis. The mesoporous, highly excavated octahedral PtCu₃ nanostructures are built with mutually perpendicular interlaced mesoporous nanosheets with a thickness of ≈4.5 nm. Benefiting from its mesoporous features, three-dimensional (3D) open surfaces, ultrathin nanosheets, and a Cu-rich surface, PtCu₃ exhibits excellent electrocatalytic performance and high antipoisoning activity toward the methanol oxidation reaction.