Sustainable Energy & Fuels最新文献

Interfacial instability between Ni-rich layered oxide cathodes and sulfide electrolytes remains a major bottleneck hindering the development of high-performance all-solid-state lithium batteries (ASSLBs). Conventional coating materials often suffer from low ionic conductivity and poor mechanical deformability, necessitating complex processing or additional interlayers. Halide electrolytes offer good stability, ionic conductivity, and softness, but their poor reductive stability with lithium metal limits their use as standalone solid electrolytes in full cells. In this work, we propose a dual-electrolyte composite cathode strategy by introducing a halide electrolyte, Li₃InCl₆ (LIC), as a functional surface coating for LiNi_0.8Co_0.1Mn_0.1O₂ (NCM). The nanosized Li₃InCl₆ particles synthesized by freeze-drying exhibit high ionic conductivity and uniform particle size distribution, making them effective as interfacial buffer layers. The optimized 15% LIC@NCM composite cathode delivers a high initial capacity of 189 mA h g⁻¹ with a coulombic efficiency of 84.4% at 0.1 C, along with remarkable cycling stability, retaining 114 mA h g⁻¹ after 250 cycles at 0.5 C. Comprehensive electrochemical and spectroscopic analyses confirm that the Li₃InCl₆ coating effectively mitigates interfacial degradation, suppresses side reactions, and facilitates ion transport across the composite interface. This study offers a facile and scalable interface engineering strategy using halide electrolytes to simultaneously enhance lithium-ion transport and interfacial stability in sulfide-based ASSLBs.

Plastic waste management is a critical sustainability challenge, but it also offers an opportunity to produce clean fuels from carbon-rich materials. In this study, we report a ruthenium catalyst supported on thermally stable mesoporous nitrogen-doped carbon (Ru/NAC) for the solvent-free hydrogenolysis of polyethylene into diesel-range hydrocarbons. The catalyst features ultrasmall Ru nanoparticles (∼1.48 nm), uniformly dispersed and stabilized by Ru–N coordination within an ordered mesoporous carbon framework. This architecture enhances polymer–catalyst interactions and enables controlled C–C bond cleavage. Under mild conditions (300 °C, 3 MPa H₂), Ru/NAC achieves a high liquid yield (86.5%) with 90.4% selectivity toward C₈–C₂₂ alkanes and a productivity of 391.1 g_p g_Ru⁻¹ h⁻¹. Mechanistic studies, including ¹³C solid-state NMR and in situ Diffuse Reflectance Infrared Fourier Transform spectroscopy, reveal that mesopore confinement and homogeneous metal dispersion synergistically promote selective depolymerization pathways. This strategy offers a practical and scalable route for transforming polyolefin waste into sustainable fuel-range hydrocarbons, advancing circular energy systems.

The development of effective electrocatalysts is vital for advancing lithium–sulfur (Li–S) batteries, particularly in addressing sluggish redox kinetics and the polysulfide shuttle effect. In this study, we systematically investigate the catalytic behavior of three tantalum-based two-dimensional (2D) monolayers, TaS₂, Ta₂C, and hybrid Ta₂S₂C, using first-principles calculations. All three systems exhibit excellent thermal and structural stability, confirmed by geometry optimizations and ab initio molecular dynamics (AIMD) simulations. Electronic structure analyses indicate metallic character in each case. Adsorption energy analysis reveals that TaS₂ binds strongly with Li₂S₄ (−2.60 eV), Li₂S₂ (−2.94 eV), and Li₂S (−3.93 eV), in sharp contrast to Ta₂C, which shows weak binding (e.g., +1.63 eV for Li₂S₄). Ta₂S₂C exhibits intermediate strength (−2.02 eV for Li₂S₂). Bader charge analysis further confirms significant electron redistribution during polysulfide anchoring, with up to 1.28|e| transferred on TaS₂. Importantly, free energy profiles along the sulfur reduction reaction (SRR) pathway demonstrate that the critical Li₂S₂ → Li₂S conversion step proceeds with a remarkably low barrier of 0.08 eV on TaS₂, compared to 0.70 eV on Ta₂C and 0.59 eV on Ta₂S₂C. These findings demonstrate that surface composition and coordination environments have a significant impact on catalytic performance. Overall, TaS₂ emerges as the most promising sulfur host, combining superior conductivity, strong polysulfide adsorption, and ultrafast catalytic kinetics, while Ta₂S₂C offers balanced anchoring and activity. This work provides atomic-scale insights for the rational design of advanced 2D electrocatalysts for high-performance Li–S batteries.

The transformation of solar radiation into chemical energy or valuable chemical compounds has garnered significant research interest, particularly in light of the global energy crisis. Hydrogen and hydrogen peroxide serve as sustainable energy sources in fuel cells, producing electricity with zero carbon emissions. Recently, the eco-friendly synthesis of H₂ and H₂O₂ from water and oxygen using porous organic polymers (POPs) as photocatalysts has drawn considerable attention. However, their applications have been limited due to low absorption of visible light and the rapid recombination of photoinduced charge carriers, while noble metal co-catalysts remain essential in all POP-based photocatalysts to achieve high rates of hydrogen evolution and hydrogen peroxide production, as well as to enhance charge separation in semiconductor photocatalysts. In this study, we demonstrate a more effective heterojunction photocatalyst—2D–2D SnS₂@TAPA-BPDA—which has a significant effect on photocatalytic H₂ evolution and H₂O₂ production. When exposed to visible light, the SnS₂@TAPA-BPDA composite achieves a hydrogen evolution rate of 1818.8 μmol h⁻¹ g⁻¹, which is approximately 30 times higher than that of the bare TAPA-BPDA POP. Similarly, for hydrogen peroxide production, the same catalyst reaches 3013.3 μmol h⁻¹ g⁻¹, nearly 14 times greater than the bare catalyst. These results highlight the significant enhancement in photocatalytic H₂ evolution and H₂O₂ generation, leading to highly effective solar-to-chemical energy conversion.

Barium titanate (BaTiO₃) has long been regarded as inactive for photocatalytic overall water splitting, in stark contrast to its perovskite counterparts SrTiO₃ and CaTiO₃. Here we report that BaTiO₃ codoped with Al³⁺ and Sc³⁺ at Ti⁴⁺ sites under flux synthesis conditions is activated as a robust photocatalyst for overall water splitting. This material achieves apparent quantum yields of 29.8% at 310 nm and 27.5% at 365 nm, representing the first demonstration of efficient overall water splitting on BaTiO₃. Comparative analyses show that BaTiO₃ doped only with Al³⁺ suffers from severe band-edge disorder, whereas BaTiO₃ codoped with Al³⁺ and Mg²⁺ exhibits clear activation with moderate efficiency. In contrast, BaTiO₃ codoped with Al³⁺ and Sc³⁺ achieves the critical defect and structural control required to push the material across the threshold from inactive to highly active. These findings overturn the long-standing perception of BaTiO₃ as unsuitable for water splitting and establish a general design principle for activating previously inactive perovskite oxides, thereby expanding the materials palette for solar-to-hydrogen energy conversion.

Wide band gap semiconductors are essential for next-generation photovoltaics, especially indoor tandem applications, because they align well with both the solar spectrum and artificial light sources. Quaternary chalcogenides, such as Cu₂ZnSnS₄ (CZTS), offer tunable bandgaps, stability, and earth abundance. In this study, Ag-alloyed CZTS (ACZTS) thin films were synthesized via a controlled chemical solution process involving spin coating deposition process and sulfur annealing. Elemental composition and morphology analyses confirmed uniform grain distribution and precise control of the Ag/Cu ratio. Structural characterization via X-ray diffraction and Raman spectroscopy revealed a gradual transformation from the kesterite to the stannite phase as the Ag concentration increased. This transformation was accompanied by lattice expansion and a change in crystallite size. Optical measurements showed a clear widening of the bandgap from approximately 1.5 eV of pure CZTS to about 1.7 eV at high Ag levels, supporting its potential use as a top absorber in tandem solar cells. These findings demonstrate that alloying with Ag effectively tailors the properties of CZTS, making it a promising, non-toxic candidate for stable and efficient use in solar cells for indoor environments or high-efficiency tandem applications.

Lithium nitrate (LiNO₃) exhibits exceptional solid electrolyte interphase-forming capabilities, cost efficiency, high thermal stability, and low environmental impact. However, its limited solubility in ester-based electrolytes means that it is frequently used only as an electrolyte additive. This study presents a low-concentration electrolyte (LCE) formulation comprising 1,2-dimethoxyethane (DME), fluoroethylene carbonate (FEC), and ethoxylated pentafluorocyclotriphosphazene (PFPN), with 0.5 M lithium nitrate (LiNO₃) serving as the sole lithium salt. In LiNO₃, strong Li⁺–NO₃⁻ interactions arise from the high binding affinity between NO₃⁻ and Li⁺, driving preferential incorporation of NO₃⁻ into the Li⁺ solvation shell to form a solvation structure dominated by contact ion pairs (CIPs). Furthermore, FEC and PFPN pull out part of DME from the Li⁺ solvation shell via intermolecular interactions, thereby reducing the proportion of DME solvent participation in the Li⁺ solvation shell and promoting the formation of nitrate-rich aggregates (AGG/AGG+). This design confers high voltage tolerance (4.4 V) and non-flammability characteristics to a 0.5 M low-salt-concentration ether-based electrolyte. It tackles the challenge inherent in LCEs, where solvent-dominated solvation architectures give rise to the formation of an organic-rich solid electrolyte interphase (SEI), culminating in suboptimal cycling stability. The approach markedly improves the cycling performance of NMC811 (9.2 mg cm⁻²)‖Li (50 μm) full cells, achieving 80% capacity retention after 150 cycles, while promoting the formation of a LiF/Li₃N inorganic composite solid electrolyte interphase (SEI). The key strategy of this work is to utilize LiNO₃ as the sole lithium salt, which paves a novel pathway for the rational design of advanced low-concentration electrolytes.

Metal halide perovskites are highly attractive for optoelectronic applications due to their exceptional optoelectronic properties. However, defect-induced non-radiative recombination and poor long-term stability continue to limit device performance. In this work, we present a Lewis base doping strategy using (4-(2,7-dibromo-9,9-dimethylacridin-10(9H)-yl)butyl)phosphonic acid (DMAcPA) to effectively passivate electron trap states in perovskite films. The phosphonic acid group in DMAcPA coordinates with undercoordinated Pb²⁺ ions, thereby suppressing trap-assisted recombination. This doping approach results in a 77% reduction in electron trap density, a fourfold enhancement in carrier lifetime, enlarged grain size, and improved film crystallinity. As a result, inverted (p–i–n) perovskite solar cells incorporating DMAcPA achieve a power conversion efficiency of 24.22% and exhibit excellent ambient stability, retaining 81% of their initial efficiency after 60 days. These findings demonstrate the potential of molecular-level doping with phosphonic acid-functionalized compounds as a general strategy for defect mitigation and performance enhancement in perovskite photovoltaics.

The alkaline hydrogen evolution reaction (HER) and urea oxidation reaction (UOR) are gaining considerable interest for boosting the overall water splitting in the context of green hydrogen production with simultaneous urea removal from wastewater. In this work, we successfully synthesized a novel cobalt-based two-dimensional (2D) metal–organic framework (MOF), named Co-IDBA-MOF, by a solvothermal method using a mixed ligand system consisting of 2,2′-iminodibenzoic acid (IDBA) and 4,4′-bipyridine (Bpy). Single-crystal X-ray analysis of the Co-IDBA-MOF confirmed its layered 2D structure. The bulk specimen of the MOF was further characterized by powder X-ray diffraction (PXRD), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric (TG) analysis, and UV-visible spectroscopic analysis. Field emission-scanning electron microscopic (FE-SEM), field emission gun-transmission electron microscopic (FEG-TEM) and atomic force microscopic (AFM) analyses uncovered the ultrathin 2D nanosheet-type morphology of the MOF, which facilitates the fabrication of 2D materials for the potential fabrication of real devices. This Co-IDBA-MOF exhibited good electrocatalytic performance in the alkaline HER at −0.241 V w. r. t. RHE at a current density of 10 mA cm⁻² (η₁₀) and a modest oxygen evolution reaction (OER) activity (1.66 V for 10 mA cm⁻² w. r. t. RHE) in an alkaline water medium. However, the anodic potential got drastically reduced to 1.55 V after the addition of 0.33 M urea due to the urea oxidation reaction (UOR). The lowering of the Tafel slope and the concomitant increase in double-layer capacitance for the alkaline hydrogen evolution reaction (HER) and urea oxidation reaction (UOR) suggested improved kinetics for overall water splitting after urea addition. Further variations in the urea concentration and the concentration of electrode materials can tune the UOR activity. This work aims to design a novel Co-MOF-based electrode material for bifunctional activity and large-scale green hydrogen production via the UOR.

We investigate the use of hydrolysate from preconditioned pine wood chips using dilute sulfuric acid for biofuel production. High-performance liquid chromatography analysis of the hydrolysate indicated the presence of pentoses, hexoses, and various degradation products, including levulinic acid, furfural, and hydroxymethylfurfural. Both detoxified and non-detoxified lignocellulosic hydrolysates were examined for lipid production (biofuel intermediates) using the oleaginous strain Cutaneotrichosporon curvatus. After five days of growth, C. curvatus achieved a maximum dry cell weight of 0.93 g per g of mixed sugars and a lipid yield of 0.23 g per g of mixed sugars. The lipid content represented 25% of the dry cell weight, suggesting that C. curvatus is a promising alternative for utilizing both C5 and C6 sugars derived from pretreated lignocellulosic biomass. Hydrothermal liquefaction of the C. curvatus broth was conducted under subcritical and supercritical water conditions. The bio-oil was extracted using dichloromethane, and the calculated higher heating values of the bio-oil were found to be 26.4, 34.4, and 37.2 MJ kg⁻¹ at 300 °C, 350 °C, and 375 °C reaction temperatures, respectively. The composition of biocrude was analyzed using GC-MS and identified oleic, palmitic, stearic, pentadecanoic, palmitic, and heptadecanoic acids. The results of this study demonstrate an integrated pathway with the potential to upgrade a mixed sugar stream into fuel intermediates.