Energy & Environmental Materials最新文献

Nosocomial infections affect implanted medical devices and greatly challenge their functional outcomes, becoming sometimes life threatening for the patients. Therefore, aggressive antibiotic therapies are administered, which often require the use of last-resort drugs, if the infection is caused by multi-drug-resistant bacteria. Reducing the risk of bacterial contamination of medical devices in the hospitals has thus become an emerging issue. Promising routes to control these infections are based on materials provided with intrinsic bactericidal properties (i.e., chemical action) and on the design of surface coatings able to limit bacteria adhesion and fouling phenomena (i.e., physical action), thus preventing bacterial biofilm formation. Here, we report the development and validation of coatings made of layer-by-layer deposition of electrospun poly(vinylidene fluoride-co-trifluoro ethylene) P(VDF-TrFE) fibers with controlled orientations, which ultimately gave rise to antifouling surfaces. The obtained 10-layer surface morphology with 90° orientation fibers was able to efficiently prevent the adhesion of bacteria, by establishing a superhydrophobic-like behavior compatible with the Cassie-Baxter regimen. Moreover, the results highlighted that surface wettability and bacteria adhesion could be controlled using fibers with diameter comparable to bacteria size (i.e., achievable via electrospinning process), by tuning the intra-fiber spacing, with relevant implications in the future design of biomedical surface coatings.

Covalent organic frameworks (COFs) after undergoing the superlithiation process promise high-capacity anodes while suffering from sluggish reaction kinetics and low electrochemical utilization of redox-active sites. Herein, integrating carbon nanotubes (CNTs) with imine-linked covalent organic frameworks (COFs) was rationally executed by in-situ Schiff-base condensation between 1,1′-biphenyl]-3,3′,5,5′-tetracarbaldehyde and 1,4-diaminobenzene in the presence of CNTs to produce core–shell heterostructured composites (CNT@COF). Accordingly, the redox-active shell of COF nanoparticles around one-dimensional conductive CNTs synergistically creates robust three-dimensional hybrid architectures with high specific surface area, thus promoting electron transport and affording abundant active functional groups accessible for electrochemical utilization throughout the whole electrode. Remarkably, upon the full activation with a superlithiation process, the as-fabricated CNT@COF anode achieves a specific capacity of 2324 mAh g⁻¹, which is the highest specific capacity among organic electrode materials reported so far. Meanwhile, the superior rate capability and excellent cycling stability are also obtained. The redox reaction mechanisms for the COF moiety were further revealed by Fourier-transform infrared spectroscopy in conjunction with X-ray photoelectron spectroscopy, involving the reversible redox reactions between lithium ions and C=N groups and gradual electrochemical activation of the unsaturated C=C bonds within COFs.

Rechargeable magnesium metal batteries need an electrolyte that forms a stable and ionically conductive solid electrolyte interphase (SEI) on the anodes. Here, we used molecular dynamic simulation, density functional theory calculation, and X-ray photoelectron spectroscopy analysis to investigate the solvation structures and SEI compositions in electrolytes consisting of dual-salts, magnesium bis(trifluoromethanesulfonyl)imide (MgTFSI₂), and MgCl₂, with different additives in 1,2-dimethoxyethane (DME) solvent. We found that the formed [Mg₃(μ-Cl)₄(DME)_mTFSI₂] (m = 3, 5) inner-shell solvation clusters in MgTFSI₂-MgCl₂/DME electrolyte could easily decompose and form a MgO- and MgF₂-rich SEI. Such electron-rich inorganic species in the SEI, especially MgF₂, turned out to be detrimental for Mg plating/stripping. To reduce the MgF₂ and MgO contents in SEI, we introduce an electron-deficient tri(2,2,2-trifluoroethyl) borate (TFEB) additive in the electrolyte. Mg//Mg cells using the MgTFSI₂-MgCl₂/DME-TFEB electrolyte could cycle stably for over 400 h with a small polarization voltage of ~150 mV. Even with the presence of 800 ppm H₂O, the electrolyte with TFEB additive could still preserve its good electrochemical performance. The optimized electrolyte also enabled stable cycling and high-rate capability for Mg//Mo₆S₈ and Mg//CuS full cells, showing great potential for future applications.

Surface area, pore properties, synergistic behavior, homogenous dispersion, and interactions between carbon matrix and metal-nanostructures are the key factors for achieving the better performance of carbon-metal based (electro)catalysts. However, the traditional hydro- or solvothermal preparation of (electro)catalysts, particularly, bi- or tri-metallic nanostructures anchored graphene (G) or carbon nanotubes (CNTs), often pose to poor metal–support interaction, low synergism, and patchy dispersion. At first, bimetallic flower-like-CuFeS₂/NG and cube-like-NiFeS₂/NCNTs nanocomposites were prepared by solvothermal method. The resultant bimetallic nanocomposites were employed to derive the 2D-nano-sandwiched Fe₂CuNiS₄/NGCNTs-SW (electro)catalyst by a very simple and green urea-mediated “mix-heat” method. The desired physicochemical properties of Fe₂CuNiS₄/NGCNTs-SW such as multiple active sites, strong metal-support interaction, homogenous dispersion and enhanced surface area were confirmed by various microscopic and spectroscopic techniques. To the best of our knowledge, this is the first urea-mediated “mix-heat” method for preparing 2D-nano-sandwiched carbon-metal-based (electro)catalysts. The Fe₂CuNiS₄/NGCNTs-SW was found to be highly effective for alkaline-mediated oxygen evolution reaction at low onset potential of 284.24 mV, and the stable current density of 10 mA cm⁻² in 1.0 m KOH for 10 h. Further, the Fe₂CuNiS₄/NGCNTs-SW demonstrated excellent catalytic activity in the reduction of 4-nitrophenol with good k_app value of 87.71 × 10⁻² s⁻¹ and excellent reusability over five cycles. Overall, the developed urea-mediated “mix-heat” method is highly efficient for the preparation of metal-nanoarchitectures anchored 2D-nano-sandwiched (electro)catalysts with high synergism, uniform dispersion and excellent metal-support interaction.

The current global warming, coupled with the growing demand for energy in our daily lives, necessitates the development of more efficient and reliable energy storage devices. Lithium batteries (LBs) are at the forefront of emerging power sources addressing these challenges. Recent studies have shown that integrating hexagonal boron nitride (h-BN) nanomaterials into LBs enhances the safety, longevity, and electrochemical performance of all LB components, including electrodes, electrolytes, and separators, thereby suggesting their potential value in advancing eco-friendly energy solutions. This review provides an overview of the most recent applications of h-BN nanomaterials in LBs. It begins with an informative introduction to h-BN nanomaterials and their relevant properties in the context of LB applications. Subsequently, it addresses the challenges posed by h-BN and discusses existing strategies to overcome these limitations, offering valuable insights into the potential of BN nanomaterials. The review then proceeds to outline the functions of h-BN in LB components, emphasizing the molecular-level mechanisms responsible for performance improvements. Finally, the review concludes by presenting the current challenges and prospects of integrating h-BN nanomaterials into battery research.

Finding appropriate photocatalysts for solar-driven water (H₂O) splitting to generate hydrogen (H₂) fuel is a challenging task, particularly when guided by conventional trial-and-error experimental methods. Here, density functional theory (DFT) is used to explore the MXenes photocatalytic properties, an emerging family of two-dimensional (2D) transition metal carbides and nitrides with chemical formula M_n+1X_nT_x, known to be semiconductors when having T_x terminations. More than 4,000 MXene structures have been screened, considering different compositional (M, X, T_x, and n) and structural (stacking and termination position) factors, to find suitable MXenes with a bandgap in the visible region and band edges that align with the water-splitting half-reaction potentials. Results from bandgap analysis show how, in general, MXenes with n = 1 and transition metals from group III present the most cases with bandgap and promising sizes, with C-MXenes being superior to N-MXenes. From band alignment calculations of candidate systems with a bandgap larger than 1.23 eV, the minimum required for a water-splitting process, Sc₂CT₂, Y₂CT₂ (T_x = Cl, Br, S, and Se) and Y₂CI₂ are highlighted as adequate photocatalysts.

As one promising carbon-based material, sp³-hybrid carbon nitride has been predicted with various novel physicochemical properties. However, the synthesis of sp³-hybrid carbon nitride is still limited by the nanaoscale, low crystallinity, complex source, and expensive instruments. Herein, we have presented a facile approach to the sp³-hybrid carbon nitride nano/micro-crystals with microwave-assisted confining growth and liquid exfoliation. Actually, the carbon nitride nano/micro-crystals can spontaneously emerge and grow in the microwave-assisted polymerization of citric acid and urea, and the liquid exfoliation can break the bulk disorder polymer to retrieve the highly crystalline carbon nitride nano/micro-crystals. The obtained carbon nitride nano/micro-crystals present superior blue light absorption strength and surprising photoluminescence quantum yields of 57.96% in ethanol and 18.05% in solid state. The experimental characterizations and density functional theory calculations reveal that the interface-trapped localized exciton may contribute to the excellent intrinsic light emission capability of carbon nitride nano/micro-crystals and the interparticle staggered stacking will prevent the aggregation-caused-quenching partially. Finally, the carbon nitride nano/micro-crystals are demonstrated to be potentially useful as the phosphor medium in light-emitting-diode for interrupting blue light-induced eye damage. This work paves new light on the synthesis strategy of sp³-hybrid carbon nitride materials and thus may push forward the development of multiple carbon nitride research.