Energy & Environmental Materials最新文献

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.

Decoupling electrical and thermal properties to enhance the figure of merit of thermoelectric materials underscores an in-depth understanding of the mechanisms that govern the transfer of charge carriers. Typically, a factor that contributes to the optimization of thermal conductivity is often found to be detrimental to the electrical transport properties. Here, we systematically investigated 26 dimeric MX₂-type compounds (where M represents a metal and X represents a nonmetal element) to explore the influence of the electronic configurations of metal cations on lattice thermal transport and thermoelectric performance using first-principles calculations. A principled scheme has been identified that the filled outer orbitals of the cation lead to a significantly lower lattice thermal conductivity compared to that of the partly occupied case for MX₂, due to the much weakened bonds manifested by the shallow potential well, smaller interatomic force constants, and higher atomic displacement parameters. Based on these findings, we propose two ionic compounds, BaAs and BaSe₂, to realize reasonable high electrical conductivities through the structural anisotropy caused by the inserted covalent X₂ dimers while still maintaining the large lattice anharmonicity. The combined superior electrical and thermal properties of BaSe₂ lead to a high n-type thermoelectric ZT value of 2.3 at 500 K. This work clarifies the structural origin of the heat transport properties of dimeric MX₂-type compounds and provides an insightful strategy for developing promising thermoelectric materials.

The all-vanadium redox flow battery (VRFB) plays an important role in the energy transition toward renewable technologies by providing grid-scale energy storage. Their deployment, however, is limited by the lack of membranes that provide both a high energy efficiency and capacity retention. Typically, the improvement of the battery's energy efficiency comes at the cost of its capacity retention. Herein, novel N-alkylated and N-benzylated meta-polybenzimidazole (m-PBI) membranes are used to understand the molecular requirements of the polymer electrolyte in a vanadium redox flow battery, providing an important toolbox for future research toward next-generation membrane materials in energy storage devices. The addition of an ethyl side chain to the m-PBI backbone increases its affinity toward the acidic electrolyte, thereby increasing its ionic conductivity and the corresponding energy efficiency of the VRFB cell from 70% to 78% at a current density of 200 mA cm⁻². In addition, cells equipped with ethylated m-PBI showed better capacity retention than their pristine counterpart, respectively 91% versus 87%, over 200 cycles at 200 mA cm⁻². The outstanding VRFB cycling performance, together with the low-cost and fluorine-free chemistry of the N-alkylated m-PBI polymer, makes this material a promising membrane to be used in next-generation VRFB systems.

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.

Eco-friendly and antimicrobial globular protein lysozyme is widely produced for several commercial applications. Interestingly, it can also be able to convert mechanical and thermal energy into electricity due to its piezo- and pyroelectric nature. Here, we demonstrate engineering of lysozyme into piezoelectric devices that can exploit the potential of lysozyme as environmentally friendly, biocompatible material for mechanical energy harvesting and sensorics, especially in micropowered electronic applications. Noteworthy that this flexible, shape adaptive devices made of crystalline lysozyme obtained from hen egg white exhibited a longitudinal piezoelectric charge coefficient (d ~ 2.7 pC N⁻¹) and piezoelectric voltage coefficient (g ~ 76.24 mV m N⁻¹) which are comparable to those of quartz (~2.3 pC N⁻¹ and 50 mV m N⁻¹). Simple finger tapping on bio-organic energy harvester (BEH) made of lysozyme produced up to 350 mV peak-to-peak voltage, and a maximum instantaneous power output of 2.2 nW cm⁻². We also demonstrated that the BEH could be used for self-powered motion sensing for real-time monitoring of different body functions. These results pave the way toward self-powered, autonomous, environmental-friendly bio-organic devices for flexible energy harvesting, storage, and in wearable healthcare monitoring.

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.

Sulfide-based inorganic solid electrolytes are promising materials for high-performance safe solid-state batteries. The high ion conductivity, mechanical characteristics, and good processability of sulfide-based inorganic solid electrolytes are desirable properties for realizing high-performance safe solid-state batteries by replacing conventional liquid electrolytes. However, the low chemical and electrochemical stability of sulfide-based inorganic solid electrolytes hinder the commercialization of sulfide-based safe solid-state batteries. Particularly, the instability of sulfide-based inorganic solid electrolytes is intensified in the cathode, comprising various materials. In this study, carbonate-based ionic conductive polymers are introduced to the cathode to protect cathode materials and suppress the reactivity of sulfide electrolytes. Several instruments, including electrochemical spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy, confirm the chemical and electrochemical stability of the polymer electrolytes in contact with sulfide-based inorganic solid electrolytes. Sulfide-based solid-state cells show stable electrochemical performance over 100 cycles when the ionic conductive polymers were applied to the cathode.

A commentary on pressure-induced pre-lithiation towards Si anodes in all-solid-state Li-ion batteries (ASSLIBs) using sulfide electrolytes (SEs) is presented. First, feasible pre-lithiation technologies for Si anodes in SE-based ASSLIBs especially the significant pressure-induced pre-lithiation strategies are briefly reviewed. Then, a recent achievement by Meng et al. in this field is elaborated in detail. Finally, the significance of Meng's work is discussed.

The relation between the structure of the silver network electrodes and the properties of Cu(In,Ga)Se₂ (CIGS) solar cells is systemically investigated. The Ag network electrode is deposited onto an Al:ZnO (AZO) thin film, employing a self-forming cracked template. Precise control over the cracked template's structure is achieved through careful adjustment of temperature and humidity. The Ag network electrodes with different coverage areas and network densities are systemically applied to the CIGS solar cells. It is revealed that predominant fill factor (FF) is influenced by the figure of merit of transparent conducting electrodes, rather than sheet resistance, particularly when the coverage area falls within the range of 1.3–5%. Furthermore, a higher network density corresponds to an enhanced FF when the coverage areas of the Ag networks are similar. When utilizing a thinner AZO film, CIGS solar cells with a surface area of 1.0609 cm² exhibit a notable performance improvement, with efficiency increasing from 10.48% to 11.63%. This enhancement is primarily attributed to the increase in FF from 45% to 65%. These findings underscore the considerable potential for reducing the thickness of the transparent conductive oxide (TCO) in CIGS modules with implications for practical applications in photovoltaic technology.