Sustainable Energy & Fuels最新文献

The sluggish kinetics of the oxygen evolution reaction (OER) and the competing chlorine evolution reaction (CER) significantly limit the efficiency of seawater electrolysis for hydrogen production. Replacing OER/CER with thermodynamically more favorable anodic reactions presents a promising strategy for reducing energy consumption and overcoming chlorine-based toxic products. This study reports a hybrid seawater electrolysis system that couples the ethanol oxidation reaction (EOR) with the hydrogen evolution reaction (HER), enabling the co-production of green hydrogen and value-added potassium acetate in alkaline seawater. Utilizing bimetallic NiCu hierarchical nanostructures supported on nickel foam (NiCu–HNS@NF) as a bifunctional electrocatalyst, this promising system required 220 mV less potential for EOR compared to OER to achieve a current density of 20 mA cm⁻². Meanwhile, the HER required a low overpotential of only 97 mV to attain the same current density, with a faradaic efficiency (FE) of 97.6%. The CO₂-free selective conversion of ethanol into acetate, along with the high faradaic efficiency (FE) for H₂, may be attributed to the bubbles-templated interconnected hierarchical nanostructures and the bimetallic synergistic effect. This study highlights the potential of ethanol-assisted seawater electrolysis as an energy-efficient and economically viable platform for sustainable hydrogen production and biomass valorization.

Na superionic conductors (NASICONs) have attracted much attention due to their unique framework structure and high capacity. However, the poor intrinsic electron conductivity severely limits further development. This work develops a soft–hard carbon composite modified Na₃V₂(PO₄)₃ (NVP) cathode with excellent rate performance and long-term cycling stability. The optimized sample exhibits excellent electrochemical performance and can deliver a specific discharge capacity of 102.7 mAh g⁻¹ at 1 C rate. At the same time, after 5000 cycles at 20 C rate, the discharge capacity can reach 82.3 mAh g⁻¹, and the capacity retention rate is 100.1%. The morphological characteristics of the NVP/C samples were investigated. Meanwhile, combined with Raman spectroscopy and electrochemical analysis, these results revealed that the synergistic interaction between soft and hard carbon components significantly enhances electronic conductivity and facilitates rapid ionic transport. This work provides a unique idea for the surface modification and synthesis of NASICON cathode materials for sodium-ion batteries.

Copper bismuthate (CuBi₂O₄) is a fascinating photocathode material for photoelectrochemical (PEC) water-splitting due to its high theoretical photocurrent density and large internal photovoltage. However, its PEC performance is hindered by insufficient light absorption, fast charge carrier recombination, sluggish interfacial charge transfer kinetics, and challenges in achieving uniform photocathode fabrication. Herein, a simple and surfactant-assisted sol–gel method is adopted to fabricate a homogeneous CuBi₂O₄ photocathode for improved PEC performance. A small amount of Pluronic P123, a triblock copolymer surfactant, was incorporated into the CuBi₂O₄ precursor sol to enhance film homogeneity and modulate the particle size during the sol–gel synthesis process. The experimental results reveal that the addition of the surfactant facilitates uniform deposition of the CuBi₂O₄ photocathode and significantly reduces its average particle size from 252 nm to 98 nm. This reduction in particle size results in approximately 2 times higher photocurrent density (−3.8 mA cm⁻² compared to −2.0 mA cm⁻²) at 0.2 V versus reversible hydrogen electrode (RHE) in 0.1 M Na₂SO₄ electrolyte with an electron scavenger. The enhanced PEC performance originates from the improved charge separation (30.5% at 0.2 V vs. RHE) and transfer efficiencies (30.1 V vs. RHE) of the surfactant-modulated photocathode. This work provides a straightforward way of fabricating robust, efficient, and large-area CBO photocathodes for PEC application.

Most of the point-of-care (POC) POC diagnostics systems require a fluid manipulation that can be controlled by microfluidic components, such as micropumps, microvalves, and micro-separators, among others. These microfluidic components require significant external energy to apply external forces. Hence, the lack of reliable and sustainable power sources impedes the widespread adoption of these devices. Since the 1970s, photobatteries have been the subject of scientific inquiry with a resurgence in recent years, catalysing the creation of diverse photobattery designs. Among these, paper-based systems have emerged as a particularly promising avenue, offering a potential solution to mitigate the environmental footprint of disposable energy storage devices. Their performance and longevity, however, are heavily dependent on the photoactive battery electrode materials and architectures employed. This comprehensive review article examines the cutting-edge research on bifunctional nanomaterials optimally suited for paper-based lithium-ion photobatteries. The focus is primarily on two-electrode configurations where a single electrode integrates both light harvesting and energy storage capabilities. Such a design is particularly advantageous for electrochemical point-of-care (POC) medical sensors, offering a compact and efficient energy solution. The work highlights the unique requirements and challenges associated with these systems and provides a comprehensive overview of potential photoactive materials. It critically evaluates their performance metrics, such as specific energy, power density, safety, and environmental impact, in the context of solar-powered POC medical sensor applications. Successful case studies and real-world applications are discussed, showcasing their potential to improve healthcare accessibility and quality, particularly in underserved and resource-constrained communities. This review underscores the transformative potential of nanostructure photobatteries and beckons researchers to partake in shaping this new field.

The urgent need for low-carbon energy alternatives has intensified interest in sustainable biofuel production pathways. This study presents a comprehensive Life Cycle Assessment (LCA) of a chemolithotrophic bacterial platform for simultaneous CO₂ mitigation and biodiesel production using Bacillus cereus SSLMC2 cultivated in 10 and 20 L bubble column bioreactors. Unlike phototrophic systems, this process leverages light-independent bacterial metabolism, offering year-round operation, high biomass yield, and compatibility with flue gas as a carbon source. Experimental data were integrated with LCA modeling using Umberto NXT Universal software and the ReCiPe 2016 and CML baseline methods to quantify environmental impacts across cultivation, biomass harvesting, lipid extraction, and transesterification stages. The results identify dewatering and homogenization as major environmental hotspots, contributing significantly to climate change, fossil depletion, and human toxicity categories. Endpoint analysis revealed human health and resource availability as the most impacted areas, primarily due to electricity use and chemical inputs. Cumulative energy demand assessments confirmed that scale-up from 10 to 20 L does not proportionally increase energy use, suggesting promising scalability. Recommendations include replacing centrifugation with membrane-based dewatering, solvent recovery systems, integration of renewable energy, and recycling of CO₂ and water. This is the first LCA study to evaluate chemolithotrophic CO₂ bio-mitigation coupled with biodiesel production at pilot scale using empirical data. The findings provide critical insights for optimizing microbial biorefineries and support the development of scalable, environmentally efficient carbon capture and utilization technologies.

The transition from fossil fuels to sustainable energy and chemical production relies heavily on efficient biomass valorization. Levulinic acid (LA), a key platform chemical from lignocellulosic biomass, serves as a versatile precursor for valuable chemicals like γ-valerolactone (GVL), a promising green solvent, fuel additive, and polymer precursor. While ruthenium-based catalysts are effective for LA hydrogenation, conventional systems like Ru/C often suffer from metal leaching and deactivation due to weak metal–support interactions. Current approaches to improve stability, such as using nitrogen-doped carbon supports, involve complex synthesis and synthetic nitrogen precursors. Addressing these limitations, we present a facile and sustainable strategy for synthesizing a robust ruthenium catalyst by directly pyrolyzing marine biomass-derived chitosan to form a self-nitrogen-doped carbon support. This catalyst exhibited superior stability and excellent recyclability in the aqueous-phase hydrogenation of LA to GVL, surpassing conventional Ru/C while maintaining activity comparable to that of leading Ru catalysts supported on N-doped carbon. Unlike other N-doped carbon supports, our method avoids synthetic N-dopants and tedious procedures, making it inherently more sustainable. Detailed characterization via XPS and H₂-TPR revealed strong metal–support interactions, facilitated by intrinsic nitrogen functionalities, effectively stabilizing the ruthenium species. This study also identifies the critical role of graphitic and pyridinic nitrogen species in controlling catalytic activity and elucidates the importance of optimizing nitrogen species and content in tailoring chitosan-derived supports. The proposed mechanism describes how Ru–N centers activate hydrogen and LA, with basic nitrogen sites aiding the dehydration step to GVL. Overall, this work features the potential of chitosan derived carbon as a sustainable and tunable support for efficient biomass hydrogenation catalysts and offers fundamental insights into the role of nitrogen doping in tailoring catalytic performance.

Commercially available sodium-ion battery (SIB) cells, with energy densities comparable to lithium-ion battery (LIB) cells based on LiFePO₄, were investigated regarding their safety behaviour under thermal abuse conditions. Tests were carried out in an inert atmosphere. The SIB-cells went into thermal runaway (TR), intriguingly, even at a rather low state of charge of 30%. The TR-event was coupled with a pronounced jelly roll ejection, challenging the interpretation of the TR-diagrams. These findings highlight the necessity of incorporating SIB-cells into the ongoing safety classification discussions for LIB-cells.

Fullerene derivative PCBM is a widely used electron transport layer (ETL) in p–i–n structured perovskite solar cells (PSCs). However, the high cost of PCBM, often exceeding that of all other active materials combined (excluding ITO), represents a significant barrier to the large-scale commercialization of PSCs, necessitating the search for more cost-effective alternatives. Herein, nine novel perylenediimide (PDI) dimers are synthesized and employed as ETLs to overcome these challenges. Electrochemical, optoelectronic, and morphological properties of the synthesized compounds were systematically compared with respect to the reference PDI derivative with a thiophene core building block. Correlations were identified between the ability of the developed materials to form high-quality, uniform films and the stabilization of the underlying perovskite layer. A further significant correlation was also observed between the LUMO level of the PDI derivative and the performance of the perovskite devices. These findings offer valuable insights into the targeted design of dimeric perylenediimide derivatives for creating stable and efficient perovskite solar cells.

In this study, binder-free nickel cobalt oxide (NiCo₂O₄) nanowire arrays with a cubic spinel structure were directly grown on nickel foam (NF) via an in situ hydrothermal process. The resulting one-dimensional nanowires exhibited a uniform morphology and a favourable bandgap of approximately 1.67 eV, making them ideal candidates as electrode materials for photo-assisted supercapacitors. Electronic structure analysis revealed the coexistence of Ni²⁺/Ni³⁺ and Co²⁺/Co³⁺ redox pairs, significantly enhancing electrochemical kinetics and facilitating efficient photo-assisted charge storage. Under illumination, the NiCo₂O₄@NF nanowires demonstrated a remarkable 54% increase in areal capacitance, from 570 to 880 mF cm⁻² at 15 mA cm⁻², attributed to the efficient separation and storage of photo-generated charges driven by surface polarization effects. An asymmetric supercapacitor device was fabricated with activated carbon (AC) as the anode and NiCo₂O₄@NF nanowires as the photoactive cathode, maintaining 88% capacitance retention after 1000 illumination cycles. Density functional theory with the on-site Hubbard U correction (DFT + U) calculations further confirmed that nickel substitution in the Co₃O₄ matrix significantly reduces the bandgap and enhances the magnetic moment, supported by asymmetric spin-resolved density of states and band structure analyses. This research provides valuable insights for developing next-generation photo-assisted energy storage solutions.

Flexible thermoelectric generators (FTEGs) have garnered considerable interest for their potential in energy harvesting applications. This study investigates the synthesis of SnSe and Bi/Te co-doped SnSe polycrystals using the solid-state reaction method, followed by the fabrication of FTEGs using a low-cost, scalable screen-printing technique. Hall effect measurements confirm successful doping, resulting in a transition from p-type to n-type conduction in SnSe. The Seebeck coefficient of the 2% Bi-doped SnSe/SnSe (p–n type) FTEG reaches −1146 μV K⁻¹, enhancing the thermoelectric performance. A maximum power output of 6.8 nW was obtained for a p–n-type FTEG consisting of SnSe and Sn_0.98Bi_0.02Se_0.97Te_0.03 at a temperature difference of 120 °C. Thermal conductivity measurements indicate that doping reduces phonon transport due to increased microstrain and dislocation density, which enhance phonon scattering. Furthermore, the FTEGs exhibited excellent mechanical stability, with less than 0.5% change in electrical resistance at bending angles up to 120° and after 500 cycles. These results suggest that Bi/Te co-doped SnSe is a potential candidate for scalable, flexible thermoelectric applications.