ACS Sustainable Chemistry & Engineering最新文献

The kinetics of the anode oxygen evolution reaction (OER) in photoelectrochemical (PEC) cells present challenges, motivating the exploration of alternative strategies such as biomass oxidation to yield high-value chemicals. In this study, we investigate the applications of nontoxic, stable, and earth-abundant α-Fe₂O₃ as a photoanode. In the first part of the research, a Ge-doped α-Fe₂O₃ thin film was synthesized via a hydrothermal method, with germanium oxide (GeO₂) introduced into the iron oxide precursor to prepare Ge-doped α-Fe₂O₃ thin films. We then identified a carbonate-bicarbonate solution as a suitable electrolyte for the α-Fe₂O₃ photoanode and for the selective oxidation of 5-hydroxymethylfurfural (HMF) into 2,5-furandicarboxylic acid (FDCA), a precursor for polyethylene 2,5-furandicarboxylate (PEF) synthesis. To further enhance photoelectrochemical oxidation performance, nickel phosphate (Ni–P), a cocatalyst, was loaded on top of the Ge-doped α-Fe₂O₃ by varying electrodeposition time and precursor concentration. Furthermore, we introduced 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) as a mediator to facilitate selective HMF oxidation. Our results indicated that an electrodeposition time of 30 min and a molar ratio of nickel to phosphate in the precursor of Ni_0.075P (Ni:P = 15:200) yield optimal results for selective oxidation. Relative to the unloaded case, the selectivity of FDCA increases from 35.4% to 67.1% after 12 h of reaction, with a simultaneous increase in yield from 11.8% to 41.0% and HMF conversion reaching 61.1%. α-Fe₂O₃ shows promise as a photoanode for the selective oxidation of HMF, and the incorporation of Ni–P as a cocatalyst significantly contributes to FDCA formation. This research presents an environmentally sustainable approach to harnessing solar energy for the conversion of biomass into valuable chemical products.

In this study, we investigate the applications of nontoxic, stable, and earth-abundant α-Fe₂O₃ as a photoanode. In the first part of the research, a Ge-doped α-Fe₂O₃ thin film was synthesized via a hydrothermal method, with germanium oxide (GeO₂) introduced into the iron oxide precursor to prepare Ge-doped α-Fe₂O₃ thin films. We then identified a carbonate-bicarbonate solution as a suitable electrolyte for the α-Fe₂O₃ photoanode and for the selective oxidation of 5-hydroxymethylfurfural (HMF) into 2,5-furandicarboxylic acid (FDCA), a precursor for polyethylene 2,5-furandicarboxylate (PEF) synthesis. To further enhance photoelectrochemical oxidation performance, nickel phosphate (Ni−P), a cocatalyst, was loaded on top of the Ge-doped α-Fe₂O₃ by varying electrodeposition time and precursor concentration.

In this study, we developed a novel CuMn₂O₄/CuMnO₂-based honeycomb structure module for thermochemical energy storage applications. The honeycomb modules (φ 32 mm × H 49 mm, 304 cpsi) were prepared using an extrusion molding method. We investigated the effects of the initial reaction temperature (700, 600, and 500 °C) and gas flow rate (5, 2.5, and 1 L/min) on the module’s heat release performance and chemical reactivity during the oxidation process. Experimental results demonstrated a maximum outlet temperature change of 46.2 ± 4.1 °C and a thermal output power of 4.97 ± 0.49 W (97.99 ± 9.59 W/kg) under optimal conditions. In terms of chemical reactivity, the module achieved a maximum conversion ratio of 0.863 ± 0.007, showing excellent chemical reaction activity.

The electrocatalytic oxidation of small organic molecules, such as ethylene glycol (EG), can be paired with the hydrogen evolution reaction (HER) to effectively lower the overall cell voltage, thereby enhancing energy efficiency for hydrogen production. Moreover, the anodic EG oxidation reaction (EGOR) can generate valuable C1 and C2 compounds, offering a sustainable approach to greener chemical production. The industrial viability of this process requires nonprecious metal electrocatalysts that demonstrate high performance at low potential and exhibit high selectivity. In this study, we report on a cost-effective electrocatalyst based on a nickel sulfide phase (Ni₃S₂) heterogeneously nucleated on the surface of nickel–iron-manganese layered double hydroxide (NiFeMn-LDH) nanosheet arrays and supported on nickel foam (NF), demonstrating exceptional activity for the coupled HER and EGOR in alkaline conditions. This Ni₃S₂@NiFeMn-LDH/NF catalyst achieves an EG-to-formate faradaic efficiency of up to 90% at 1.5 V, with glycolate and oxalate as minor byproducts. Density functional theory calculations reveal that the EGOR was facilitated by the phase-separated Ni₃S₂, which lowers the energy barrier of the rate-limiting step. This work presents a promising, sustainable pathway for hydrogen production alongside value-added chemical generation from the electrooxidation of EG.

The dynamic behaviors of interfacial nanobubbles play a pivotal role in determining the efficiency of hydrogen evolution reaction (HER), yet their regulation remains a significant challenge. Ionic liquids (ILs), with their exceptional interfacial properties and broad applications in electrochemistry, offer a promising avenue for tuning nanobubble behaviors during HER. In this study, we employed nanoelectrodes to manipulate the generation of individual H₂ nanobubble and investigated the effects of two ILs ([Bim][HSO₄] and [Bmim][HSO₄]) on nanobubble behavior through electrical signal monitoring and molecular simulations. The results show that H₂ nanobubble needs a higher critical nucleation concentration in [Bim][HSO₄] solution than that in [Bmim][HSO₄] solution, suggesting a pronounced inhibitory effect of [Bim][HSO₄] on nanobubble nucleation. Furthermore, nanobubbles in [Bim][HSO₄] exhibited distinctive interfacial characteristics, including smaller contact angles and greater heights, which facilitate their growth and aggregation. Density functional theory and molecular dynamics simulations confirmed that compared with [Bmim][HSO₄], the stronger adsorption of [Bim][HSO₄] at the electrode interface enhances the hydrophilicity, altering the nucleation and growth behaviors of nanobubbles. This research provides a mechanistic understanding of H₂ nanobubble behavior in IL systems, offering new strategies for optimizing interfacial processes in electrochemical applications.

This study investigated an efficient catalyst configuration to enhance the recycling of waste electrical and electronic equipment (WEEE) fractions into aromatic hydrocarbons. Two engineered WEEE fractions, low-grade (LGEW) and medium-grade (MGEW), were used as feedstock in an ex situ catalytic pyrolysis process conducted in a two-stage lab-scale reactor. The first stage involved a batch pyrolyzer, followed by a fixed-bed catalytic reactor. The interaction between catalyst active sites and pyrolysis vapors played a key role in determining the chemical functionality of the surface intermediates. Five catalytic modes were tested: CaO, HZSM-5, Fe/HZSM-5, and a combination of CaO and HZSM-5 in mixed and separate bed configurations, with a catalyst-to-feedstock ratio of 0.15 w/w. The iron-loaded zeolite favored gas production, while CaO effectively converted acids into ketones. The dual-catalyst mixed bed of CaO and HZSM-5 exhibited the best catalytic synergy, enhancing the production of aromatic hydrocarbons and decarbonizing the process. However, metal doping increased catalyst coke formation due to more Lewis acid sites and the production of polycyclic aromatic hydrocarbons. Overall, this study provides a comparative analysis of catalyst activity during the thermochemical conversion of WEEE.

Ex situ catalytic pyrolysis of WEEE using various catalyst configurations focuses on maximizing aromatic yields, supporting efficient recycling and energy recovery.

Bacterial-infected skin wounds can lead to severe, life-threatening complications including multiple organ failure and potentially death. An ideal strategy involves simultaneously inhibiting bacterial infections, eliminating the reactive oxygen species generated by infection, and providing a supportive microenvironment for tissue repair. In this study, a flexible wood-based hydrogel (FW@PA-hydrogel) loaded with phytic acid (PA) was developed, leveraging the unique hierarchical porous structure and anisotropy of wood, along with natural biomass materials known for their biological activity, carboxymethyl chitosan (CMCS), coumarin, and PA. The FW@PA-hydrogel was successfully fabricated by immersing a coumarin-modified CMCS (C-CMCS) and PA mixed solution into flexible wood that had undergone removal of hemicellulose and lignin. This was followed by a high-efficiency photodimerization reaction of coumarin, triggered by 365 nm light irradiation. The resulting hydrogel exhibited reinforced mechanical properties while retaining the remarkable biological activity of fragile biomaterials. In vitro experiments demonstrated that the FW@PA-hydrogel possessed the ability for cell proliferation, antioxidation properties, and antibacterial activity. In murine bacterial-infected wounds, the FW@PA-hydrogel effectively reduced local inflammation and bacterial infection and accelerated wound healing by promoting cell proliferation, stimulating granulation tissue formation. This study presents a promising strategy for utilizing sustainable yet fragile biomaterials derived from biomass for potential wound treatment.

CO₂ foam fracturing technology is an advantageous method for extracting unconventional resources. However, foam fracturing faces challenges, such as high costs, difficulty in handling surfactants, and potential environmental risks. To address these issues, this study combines CO₂-responsive surfactants with zwitterionic surfactants to construct a reusable CO₂-responsive viscoelastic foam fracturing fluid system. The mechanism of foam stabilization is revealed through the examination of interfacial characteristics, bulk properties, and microstructural features. Furthermore, the study systematically investigates the drainage kinetics of the CO₂-responsive viscoelastic foam fracturing fluid under high-temperature and high-pressure conditions, uncovering its unique properties under high-pressure environments and the synergistic enhancement effects of OAB+DOAPA-CO₂ (olefinic amine betaine + oleyl amide propyl dimethylamine) at high temperatures. Finally, the performance of the fracturing fluid is tested. It was found that adding DOAPA-CO₂ into OAB increases the base-fluid viscosity by 491.64% and extends the drainage half-life by 281.65%. This is primarily due to the formation of pseudogemini surfactants between OAB and DOAPA-CO₂, enhancing the foaming ability of the foam fracturing fluid. Additionally, the mixed wormlike micelles formed are stronger, and the network structure is denser, significantly improving foam stability. Interestingly, as pressure increases, the foam stability of this system improves, owing mainly to the swelling of the wormlike micelles; such exceptional stability under high pressure is highly beneficial during fracturing operations. Meanwhile, the activation energies (E_a) for the OAB and OAB+DOAPA-CO₂ systems are 579.47 and 1009.73 J/mol, respectively, indicating that pseudogemini surfactants enhance foam thermal resistance. Performance evaluations show that the damage rate of this fracturing fluid is only 6.15%, making it reservoir-friendly. Moreover, by controlling the introduction of CO₂/N₂, the base fluid can switch between high- and low-viscosity modes, facilitating the recovery of the fracturing fluid. This study provides technical support for reducing costs associated with CO₂ utilization (CO₂ foam fracturing) and mitigating the environmental risks posed by surfactant discharge.

Iron-based bimetallic sulfides featuring dual redox-active centers and abundant reserves are gradually emerging as potential anodes for advanced sodium-ion batteries (SIBs). However, they still suffer from capacity fading and inferior rate capability due to volumetric expansion and inadequate conductivity. Herein, isocubanite CuFe₂S₃ nanoparticles embedded in N,S-codoped porous carbon fiber (CuFe₂S₃@C) have been constructed by electrospinning and subsequent sulfuration processes using polystyrene (PS) nanospheres as the absorbent and void regulator. Precise regulation of the void structure in composite materials is achieved by the selection of PS nanospheres. Furthermore, the introduction of Cu atoms leads to enhanced conductivity and a low Na⁺ migration barrier in CuFe₂S₃@C. Synchrotron radiation measurements provide compelling evidence for the enhanced strength of the Fe–S bond, facilitating the maintenance of structural stability. Additionally, its structural reversibility is supported by the consistent ⁵⁷Fe Mössbauer spectra of the pristine and cycled states. Consequently, the optimized CuFe₂S₃@C exhibits outstanding cyclic stability (delivering a reversible capacity of 360 mAh g^–1 after 800 cycles at 5 A g^–1, with almost a 100% capacity retention) and impressive rate capability (252 mAh g^–1 at 30 A g^–1). When paired with a commercial Na₃V₂(PO₄)₃ cathode, the coin full cell yields an 86.5% capacity retention after 200 cycles. This work encourages the development of bimetallic sulfide anodes with excellent sodium storage performance.