Sustainable Energy & Fuels最新文献

Coal has long been a significant component of China's energy system, and solid waste products from continuous mining, including coal gangue, have raised serious environmental issues. An exponential growth trend in the accumulation volume of coal gangue not only exacerbates the ecological carrying pressure of the mining area but also contributes to the cross-pollution of water, soil, and gas ecosystems through dust diffusion, heavy metal leaching, and other ways. Technical and financial limitations keep the resource conversion rate and added value at a low level, despite the current disposal technology system having established core application modes, such as ecological restoration in mining regions and substituting for building aggregate. The directional activation of coal gangue makes it highly promising for applications in sewage treatment, as it creates an abundance of active sites and unique porous structures on its surface. This review systematically summarizes the research progress on coal gangue-based modified materials in the field of sewage treatment, focusing on their physicochemical properties, adsorption, and photocatalytic reaction mechanisms. Research methods for modifying coal gangue include physical, chemical, biological, and other techniques. Modified materials derived from coal gangue encompass a range of composite materials, functional materials, and other types of materials. The text also addresses the limitations and challenges faced in the development of these modified materials. Furthermore, it provides recommendations for the future utilization of coal gangue resources, serving as a valuable reference for scholars in related fields.

Roughness-induced resistivity and surface scattering components play a vital role in the optimization of charge carrier transport properties in thin film surfaces. In the present work, the effects of surface roughness on thermoelectric (TE) parameters, namely, the Seebeck coefficient (S), electrical conductivity (σ) and power factor (PF) are investigated. The melt quenching method was employed for the synthesis of β-Zn₄Sb₃. Thin films of various thicknesses ranging from 69 nm to 363 nm were deposited using a thermal evaporation process, which resulted in variation of the surface roughness from 6.94 nm to 37.51 nm. The maximum S and PF values of 227 μV K⁻¹ and 814 μW m⁻¹ K⁻² at room temperature (RT) were obtained for the thin film with a roughness of 28.94 nm, which represented 3.05- and 41.84-fold enhancements, respectively, over the corresponding values for the film with a roughness of 6.94 nm. The enhancement of the S values with increasing roughness was attributed to the introduction of surface energy filtering effects. The maximum σ value of 2.25 × 10⁴ S m⁻¹ was obtained for the film with a roughness value of 21.75 nm. The initial increasing trend in the σ values with increasing roughness was attributed to the longer mean free path for the carriers caused by the increased crystallite sizes, and the subsequent decreasing trend was attributed to the increased resistivity, surface scattering and trapping of carriers caused by the dominance of roughness effects. X-ray diffraction (XRD) and Raman spectroscopy were employed to investigate the structural characteristics of the surfaces which revealed enhancement of the crystallite sizes with increasing film thickness. The film thicknesses of the prepared surfaces were determined by cross-sectional field emission scanning electron microscopy (FESEM) and found to be 69 nm, 146 nm, 239 nm, 286 nm and 363 nm. Atomic force microscopy (AFM) was employed to investigate the topographical characteristics and height irregularities of the surfaces. 3D micrographs of the surfaces were constructed, and parameters including roughness, skewness and kurtosis were determined. The surface roughness was consistently enhanced with increasing thickness, which was attributed to the vertical accumulation and growth of larger crystallites. Ultraviolet visible spectroscopy (UV-vis) was employed to investigate the optical properties and estimate the bandgaps. The reduction in the bandgaps was attributed to the reduced confinement effects and enhanced light absorption tendency of rougher surfaces.

Energy storage (ES) plays a vital role in decarbonizing energy systems, yet its sustainability implications remain critical during its rapid deployment across mobile and stationary applications. This study presents the first systematic literature review focused on the assessment methods applied to ES systems in the sustainability context, by analyzing 205 peer-reviewed studies from the past five years. The review identifies Techno-Economic Analysis (TEA) and Life Cycle Assessment (LCA) as the most commonly employed methods, with a strong technological focus on hydrogen-based systems and batteries. In contrast, a limited number of studies consider social aspects in the sustainability context. An increasing trend toward integrated economic and environmental assessments is observed, though their coherence is often limited due to the absence of a standardized methodological framework. Most studies apply narrow system boundaries, frequently omitting critical life cycle stages such as the use phase and end-of-life. This paper provides a methodological overview of applied approaches, summarizes key indicators and gaps, and offers recommendations to enhance the comprehensiveness of ES sustainability assessments. Additionally, targeted suggestions are delivered for practitioners, method developers and policy actors to improve the quality and applicability of future assessment practices.

Rechargeable aqueous zinc-ion batteries (ARZIBs) have gained considerable attention as sustainable energy storage systems due to their inherent safety, environmental friendliness, and low cost. Among various cathode candidates, β-MnO₂ is particularly attractive owing to its structural stability and abundance. However, its practical application is hindered by the dissolution of Mn²⁺ ions during cycling, which leads to poor long-term performance. In this study, β-MnO₂ was synthesized via a hydrothermal method and integrated into electrodes using both conventional PVDF and a novel water-based, cross-linked binder system composed of xanthan gum and citric acid (c-XG-CA). The c-XG-CA binder, abundant in hydroxyl, carboxyl, and acetyl groups, was shown to enhance Mn²⁺ adsorption capacity, improve electrode adhesion, and increase hydrophilicity compared to PVDF. The formation and stability of the cross-linked structure, along with its manganese ion adsorption behavior, were verified through FTIR and DFT analyses. Electrochemical evaluations revealed that the β-MnO₂-c-XG-CA cathode achieved superior cycling stability (73% capacity retention after 200 cycles at C/2) and higher diffusion coefficients. Post-cycling XRD and SEM characterization studies indicated the formation of reversible Zn–buserite and Zn_x(OTf)_y(OH)_2x−y·nH₂O phases. These findings demonstrate that the c-XG-CA binder offers significant structural and electrochemical advantages, making it a promising alternative to conventional binders for high-performance ARZIBs.

To enhance power adequacy in low-carbon power systems across a multi-timescale and improve the utilization of renewable energy, this work proposes a coordinated strategy for short-term power dispatch and long-term energy shifting in a hybrid integrated energy system (IES) supported by diversified energy storage. A time-period averaging method is employed to analyze the annual net power sequence, taking into account seasonal variations in renewable generation and load demand, thereby revealing supply–demand adequacy across different seasons. Based on the source–load matching characteristics, a long-term operational strategy for seasonal energy storage modules is explored to realize inter-seasonal energy shifting. Subsequently, a collaborative scheduling model for short- and long-term energy storage is developed, aiming to balance power regulation and energy adequacy, with a particular focus on the role of seasonal storage in alleviating seasonal power shortages and enhancing system economic and environmental performance. The results demonstrate that the coordinated operation of diversified energy storage systems significantly improves the energy efficiency, reduces energy losses, and lowers dependence on external energy supply in the hybrid IES. Under the proposed joint long–short-term storage strategy, the system independence reaches 85%. In terms of operational cost, energy costs and carbon emission costs are reduced by 8.56% and 11.35%, respectively, compared to short-term-only and long-term-only strategies. Although the inclusion of seasonal storage modules, such as electrolyzers and fuel cells, leads to a 4.31% increase in maintenance costs within a certain capacity range, it results in a 6.92% reduction in both energy and carbon emission costs. The proposed long–short-term coupled scheduling strategy for the hybrid IES effectively enhances system operational efficiency and adaptability.

Screen-printed supercapacitors have become a promising energy storage solution, combining high power density, rapid charge and discharge capabilities, and long cycle life, while also offering a cost-effective and scalable manufacturing method. This review explores the principles of screen-printed supercapacitor devices, highlighting the importance of energy storage mechanisms in supercapacitors and the advantages of using screen-printing technology for device fabrication. A detailed overview of screen-printing technology, its historical evolution in electronics, and comparisons with other fabrication methods such as photolithography, inkjet printing, and vacuum deposition are presented. The review also discusses the materials used in screen-printed supercapacitors, including carbon-based, graphene oxide, MXene-based, and metal sulfide materials, as well as the integration of metal–organic frameworks (MOFs) in enhancing electrochemical performance. While screen-printed supercapacitors offer several advantages in terms of cost, scalability, and flexibility, challenges in their development remain. These challenges include issues with ink formulation and conductivity, material compatibility with substrates, electrode architecture, process optimization, and performance limitations. Furthermore, print resolution, patterning accuracy, and the durability and flexibility of screen-printed supercapacitors for wearable or portable devices continue to pose significant concerns. Despite these hurdles, recent innovations are paving the way for improved performance and scalability. New approaches, such as co-doping and the use of hybrid materials, are being explored to enrich the electrochemical properties of screen-printed supercapacitors. The potential for integrating screen-printed supercapacitors into practical applications, such as wearable electronics, IoT devices, and energy harvesting systems, is also discussed. These supercapacitors enable the development of self-sustaining systems, such as wireless sensors and flexible electronics, that benefit from the combination of high power and fast energy storage capabilities. The review concludes with a look at the future direction of screen-printed supercapacitors, focusing on sustainability through the use of eco-friendly materials, the potential for large-scale production, and the commercialization prospects of this technology.

Copper nanowires with fivefold twinned structures (t-CuNWs) are shown to be effective as cathode catalysts for the electrochemical CO₂ reduction reaction (CO₂RR) in a zero-gap electrolyzer to produce ethylene. The t-CuNWs, with surfaces enclosed by (100) facets, were selected for their enhanced CO adsorption strength, which along with the presence of the twin boundary defects, are proposed to promote C–C coupling—a key pathway toward multi-carbon (C₂) products. We also find that the entangled t-CuNWs exhibit enhanced hydrophobicity when compared to commercial Cu nanoparticles (CuNPs), which reduces electrode flooding and contributes to enhance the stability of the cathode. These characteristics distinguish t-CuNWs from CuNPs in terms of activity (overpotential, selectivity) and stability. The t-CuNWs exhibited ∼40% C₂H₄ Faradaic efficiency (FE) for more than 4 hours under a current density of 100 mA cm⁻², while commercial CuNPs exhibited ∼20% C₂H₄ FE for less than 4 hours and the CuNPs devices consistently required increased operating voltages. These findings highlight the potential of (100) faceted t-CuNWs for C₂ product formation in CO₂RR with facet engineering and hydrophobicity control.

2,5-Bis(furan-2-ylmethyl)cyclopentan-1-one (FCFDH), a C₁₅ precursor for renewable jet fuel range cycloalkanes and high-value electronic photolithography material, was selectively synthesized via a cascade aldol condensation/hydrogenation reaction of furfural and cyclopentanone under solvent-free conditions. Non-noble metal Cu and Ni modified MgAl-hydrotalcite (Cu₂Ni₁/MgAl-HT) was found to be an effective and stable catalyst for this reaction. Under the optimized conditions (423 K, 4 MPa H₂, 10 h), 97.0% cyclopentanone conversion and 82.0% carbon yield of FCFDH were achieved. Based on the characterization results, the presence of Ni and Cu species increased the acidity of MgAl-HT and formed Ni–Cu alloy particles with an average size of 2.33 nm during the preparation of the catalyst. Both effects facilitate the aldol condensation of furfural and cyclopentanone and the formation of FCFDH by the selective hydrogenation of CC bonds.

Air-cathode microbial fuel cells (MFCs) offer a sustainable approach to bioelectricity generation, but their commercialization is hindered by costly platinum catalysts and inefficient microbial electron transfer. This study investigates bio-palladium (bio-Pd) nanoparticles as a cost-effective cathode catalyst and optimizes microbial consortia to enhance MFC performance. Four cathode configurations were tested, two incorporating bio-Pd (9.6–16.9 nm, characterized via XRD and SEM-EDS), alongside sulfate-reducing bacteria (SRB) and marine bacteria (MB) cultures. The CM3 cathode, combining bio-Pd, activated charcoal, and carbon black, achieved a peak power density of 3.70 ± 0.15 mW m⁻², six times higher than the control, with a low internal resistance of 210 ± 15 Ω m². MB, dominated by electroactive Paraclostridium sp., outperformed SRB, delivering 4.18 ± 0.17 mW m⁻² due to its dense biofilm (85% anode coverage) and efficient direct and indirect electron transfer, as confirmed by 16S rRNA sequencing and SEM. These advancements, yielding power densities comparable to bio-catalytic systems, highlight bio-Pd's potential as a sustainable alternative to platinum and Paraclostridium's role as a high-performance inoculum. Addressing South Africa's energy challenges and UN Sustainable Development Goals (6, 7, 9, 13), this work paves the way for scalable MFCs in wastewater treatment and renewable energy, though long-term stability requires further exploration.