ACS Applied Nano Materials最新文献

A facile, cost-effective, and scalable method for producing turbostratic holey graphene (tHG) nanosheets has been developed using an age-old atmospheric plasma spray technique. This single-step, residue-free process originates from the hole and simultaneously induces twisting in the graphene layers. The twisting minimizes electronic interactions between the layers, increasing interlayer spacing and significantly enhancing the graphene’s effective specific surface area. The fabricated tHG electrode exhibits the highest specific capacitance of 220.4 F g^–1 at 0.5 A g^–1, an energy density of 27.54 W h kg^–1, and a power density of 225 W kg^–1 in the three-electrode system. Furthermore, the electrode exhibits outstanding electrochemical stability, retaining about 92% of its capacitance after 10,000 cycles. These characteristics position the tHG as a highly promising material for next-generation high-performance supercapacitors.

CO₂ electroreduction catalyst with a broad potential range and high selectivity is important for ensuring consistent efficiency and reliability in renewable energy integration into electrocatalytic processes. In this study, we find that the addition of different the fourth elements would have different effects on the ternary AgCuAu nanoporous alloy catalyst, which is an optimized catalyst in our previous work. The addition of Mo exhibits the lightest negative effect on the intrinsic activity of AgCuAu due to the highest electronegativity of Mo among these doping elements (Mo, Ni, Ti, and Ce). Interestingly, the Mo addition in the Al₂AgCuAu-based precursor alloy results in nanoporous AgCuAuMo with thin nanobelt-like ligaments and greatly enhanced specific surface area, probably due to the low surface diffusion rate of Mo and its direction-selected passivation during the dealloying. As a result, the nanoporous multicomponent AgCuAuMo alloy (NP-Ag₃Cu₃Au₃Mo_0.5) achieves a Faradaic efficiency (FE) for CO of more than 90% over a wide potential window of ∼1.0 V, peaking at 95.7% at −0.973 V versus the reversible hydrogen electrode (RHE). A CO partial current density (j_CO) of 202 mA/cm² can be achieved at −1.373 V vs RHE. This work highlights multicomponent alloys as effective catalysts for promoting the electrochemical conversion of CO₂.

The overall hydrazine splitting (OHzS, N₂H₄ → N₂ + 2H₂) reaction, which is integrated by electrocatalytic hydrazine oxidation reaction (HzOR) and hydrogen evolution reaction (HER), provides an energy-efficient alternative to conventional overall water splitting (OWS) for sustainable hydrogen production. Herein, we present the controlled synthesis of Rh₁Sb₁@Rh–Sb nanoflowers (NFs) that comprise intermetallic Rh₁Sb₁ nanodendrite cores and ultrathin Rh–Sb random alloy nanosheet shells. The alloying of Sb enhances both HzOR and HER performances of Rh nanocatalysts through modulation of growth mechanisms, morphological evolution, and surface electronic configurations. Remarkably, a symmetrical OHzS electrolyzer employing Rh₁Sb₁@Rh–Sb NFs as bifunctional catalysts for both electrodes achieves the current densities of 100 and 500 mA cm^–2 at cell voltages of merely 0.216 and 0.700 V (without iR compensation), respectively, corresponding to 88.1% and 71.9% reductions in electricity consumption compared to alkaline OWS systems. Furthermore, a rechargeable zinc–hydrazine (Zn–Hz) battery using Rh₁Sb₁@Rh–Sb NFs as the positive electrode exhibits high energy efficiency, power density, and durability. The prototype device, integrating a photovoltaic cell, a Zn–Hz battery, and an OHzS cell, demonstrates the potential for efficient and simultaneous solar energy storage, hydrazine pollutant remediation, and hydrogen generation, offering a promising avenue for practical applications.

While monolayers of WSe₂, an intrinsic p-type two-dimensional semiconductor, have been widely studied for their optical and electrical properties, large-scale synthesis of WSe₂ monolayers via chemical vapor deposition (CVD) can be challenging due to the high temperatures required to generate sufficient W vapor phase from oxide precursors. Utilizing a mixture of NaCl and tungsten oxide as a source enables lower growth temperatures in atmospheric pressure CVD to 825 °C–850 °C. However, the increased W vapor pressure can disrupt the balance between W and Se supplies during the slow cooling process, causing uncontrolled overgrowth at the edges of the WSe₂ flakes. This issue is effectively addressed by employing thermal quenching immediately following growth, resulting in monolayer WSe₂ flake nanostructures with uniform morphology and optical properties. The synthesized WSe₂ monolayers exhibit characteristic p-type semiconducting behaviors with a positive photoresponse.

In this study, we demonstrate the synthesis of 0D/1D Bi₂MoO₆/Na₂Ti₃O₇ (BMT) nanocomposites employing an in situ hydrothermal method for the photocatalytic conversion of benzyl alcohol to benzaldehyde. Various advanced techniques, including X-ray diffraction, transmission electron microscopy, scanning transmission electron microscopy, and a range of spectroscopic methods were employed for structural and morphological analysis of the nanocomposites. The BMT-10 heterostructure, synthesized by loading 10 wt % Bi₂MoO₆ on the surface of Na₂Ti₃O_7, showcases exceptional photocatalytic activity, achieving a conversion rate of 6.8 mmol_{converted BzOH} g_cat^–1 h^–1. This rate surpasses most reported values and is comparable to the best-performing catalytic systems for the selective photooxidation of benzyl alcohol driven by blue LED irradiation (450 nm < λ < 495 nm). The extraordinary performance results from the elevated charge separation and an effective inhibition in charge recombination rates, facilitated by the synergistic effect of the BMT-10 heterostructure. Active intermediate trapping experiments confirm that·O₂^–,·OH, and h⁺ radicals are the primary reactive species responsible for the improved activity, adopting a Z-scheme charge dynamics approach. In addition, the XPS results show that benzyl alcohol exhibits a large adsorption affinity for BMT-10, whereas benzaldehyde shows a weak affinity, which aids the conversion of the reactants. After five consecutive cycles, the photocatalytic activity of the BMT-10 heterostructure remained unchanged, indicating excellent stability during repeated use. This work presents a facile and effective method for optimizing the photocatalytic selective oxidation of benzyl alcohol to benzaldehyde, offering significant potential for sustainable chemical synthesis.

Two-dimensional transition metal carbide Ti₃C₂T_x, with its large surface area, excellent conductivity, and abundant surface terminations (T_x), has found broad applications in optoelectronic devices. To address issues such as energy level misalignment, low conductivity, and surface defects at the HTL/perovskite interface in inverted perovskite solar cells (p-i-n PSCs), this study proposes an interface passivation strategy based on MXene to regulate the buried interface of NiO_x/MeO-2PACz-based p-i-n PSCs. Experimental results show that Ti₃C₂T_x, when used as an interface passivation layer, increases the work function (WF) of MeO-2PACz, facilitating energy level alignment. The abundant hydroxyl groups (−OH) on the surface of Ti₃C₂T_x undergo continuous hybridization reactions with P atoms, forming strong Ti–O–P covalent bonds that provide an effective pathway for hole transport, thereby reducing charge accumulation at the interface. Additionally, MXene-doped MeO-2PACz was used as a control group to further reveal the dual passivation mechanism of MXene on both the MeO-2PACz and the underlying perovskite interface. Ultimately, compared to PSCs with undoped HTLs, the power conversion efficiency (PCE) of PSCs increased by 6% with HTL doping and by 10.7% with interface passivation. This study expands the application of Ti₃C₂T_x in HTLs and provides a pathway for its use in the fabrication of highly efficient and stable PSCs.

This computational study shows that partial ligation of metal chalcogenide clusters can lead to a class of catalysts with low oxidation barriers for CO oxidation. Two metal chalcogenide clusters, W₆Se₈ and Mo₆Te₈, were investigated for their catalytic activity toward CO oxidation, a crucial reaction with substantial environmental and industrial implications. Bare clusters are marked by high oxidation barriers. However, DFT analyses reveal that the attachment of organic electron-donor ligands, including trimethylphosphine, triethylphosphine, and N-ethyl-2-pyrrolidone, enhances the catalytic performance. A progressive decrease in activation barriers was observed through systematic ligation, reaching a minimum for W₆Se₈-(PEt₃)₂ at 0.16 kcal/mol. Detailed investigations, including Hirshfeld charge analysis, natural population analysis, and intrinsic reaction coordinates calculations, provide molecular-level insight into observed progressions. This study advances our understanding of catalytic mechanisms in metal chalcogenide clusters and highlights the intricate relationship between ligand-induced electronic effects and activation barriers. The results of this computational investigation open up possibilities for designing highly efficient catalysts for CO oxidation.

Membranes have seen growing interest in employing 2D materials for water treatment and desalination, aiming to enhance the performance of the current technologies. Among these 2D materials, MoS₂ nanosheets have recently attracted significant attention. Current fabrication approaches of MoS₂-based membranes require intensive electrochemical or sonication steps, which may hinder scalability. Besides, top-down methods usually produce MoS₂ slabs with large size distributions, creating detrimental defects affecting selectivity. We present a single-step bottom-up MoS₂ synthesis that yields highly concentrated solutions containing exclusively MoS₂ single-layer nanosheets allowing a perfect laminar stacking on poly(ether sulfone) (PES) support leading to excellent monovalent salt rejection (99.7% ± 0.5 NaCl).

Graphitic carbon nitride (g-C₃N₄) is a photocatalyst that has been extensively investigated. Unfortunately, g-C₃N₄ suffers from the challenges of insufficient light absorption and rapid complexation of photogenerated charges. Modification methods such as defect engineering and nanostructure reconstruction can improve photocatalytic performance. This is because modification can improve carrier separation efficiency, increase active sites and increase light absorption, etc. Here, we demonstrate a simple approach to fabricate nanosheet-stacked g-C₃N₄ (M-CN₆₀₀) tubes with carbon vacancies (V_Cs) and used for photocatalytic water splitting to hydrogen production. M-CN₆₀₀ was prepared by the thermal polymerization of precursors. These precursors were obtained through the melem induced by methanesulfonic acid. Due to the nano effect, the obtained M-CN₆₀₀ exhibits a significantly higher specific surface area (105.2 m² g^–1) and pore volume (0.391 cm³ g^–1) compared to pristine g-C₃N₄ (B-CN). This creates more reaction sites, which improve the performance of photocatalytic H₂ production. The nanosheet-stacked structure reduces the transport distance of photogenerated carriers to the material surface. In addition, M-CN₆₀₀ possesses more negative conduction band positions with stronger photocatalytic reduction ability. Moreover, due to the presence of V_Cs in the catalyst, the separation of photogenerated electron and hole pairs is accelerated. Under visible light (λ > 420 nm), the obtained M-CN₆₀₀ exhibits excellent photocatalytic H₂ evolution performance, which is 21.5-fold higher than that of B-CN. This work provides a method for preparation of nanostructured g-C₃N₄ with efficient photocatalytic performance.

Lactose serves as a crucial biomarker for assessing the quality and safety of milk. Therefore, the precise measurement of the lactose content is of paramount importance. Herein, we demonstrate that vanadium pentoxide (V₂O₅) nanobelts exhibit lactose oxidase-like activity. Additionally, a colorimetric biosensor for lactose detection was developed by leveraging a cascade reaction mechanism of V₂O₅ nanobelts possessing lactose oxidase-like and peroxidase-like activities. The sensor shows a linear response from 0.1 to 1.0 mM lactose, with a detection limit of 0.04 mM, and demonstrates accuracy and reliability in milk analysis. The accuracy of the proposed colorimetric method was verified by capillary electrophoresis in five milk samples. A self-designed portable device incorporating this technology serves to enhance its potential for practical application, enabling the precise and convenient detection of lactose levels in milk. This development not only simplifies the measurement process but also broadens the scope of its use in various settings, including on-site testing and quality control.