Search Results (153)

Electrocatalytic urea oxidation reaction (UOR) is a promising dual-purpose approach for hydrogen production and wastewater treatment, addressing critical energy and environmental challenges. However, conventional anode materials often suffer from limited active sites and high charge transfer resistance, restricting UOR efficiency. To overcome these issues, a novel NiP@PNC/NF electrocatalyst was developed via a one-step thermal annealing process under nitrogen, integrating nickel phosphide (NiP) with phosphorus and nitrogen co-doped carbon nanotubes (PNCs) on a nickel foam (NF) substrate. This design enhances catalytic activity and charge transfer, achieving current densities of 50 mA cm⁻² at 1.34 V and 100 mA cm⁻² at 1.43 V versus the reversible hydrogen electrode (RHE). The electrode’s high electrochemical surface area (235 cm²) and double-layer capacitance (94.1 mF) reflect abundant active sites, far surpassing NiP/NF (48 cm², 15.8 mF) and PNC/NF (39.5 cm², 12.9 mF). It maintains exceptional stability, with only a 16.3% performance loss after 35 h, as confirmed by HR-TEM showing an intact nanostructure. Our single-step annealing technique provides simplicity, scalability, and efficient integration of NiP nanoparticles inside a PNC matrix on nickel foam. This method enables consistent distribution and robust substrate adhesion, which are difficult to attain with multi-step or more intricate techniques. Full article

Biopolyols derived from solid fats of both vegetable origin (coconut oil (P/CO) and palm oil (P/PA)) and animal origin (pork fat (P/PO) and duck fat (P/DU)) were used to produce thermal insulation polyurethane foams. The biopolyols were characterized by hydroxyl numbers in the range of 341–396 mgKOH/g, a viscosity of 60–88 mPa·s, and a functionality of 2.3–3.4. Open-cell polyurethane foams were obtained by replacing from 50 to 100 wt.% of a petrochemical polyol with the biopolyols from solid fats. The most advantageous properties were found for the materials modified with the biopolyol based on pork fat, which was attributed to its high degree of cell openness. At a low apparent density, the foam materials were characterized by good dimensional stability. The use of solid fats offers new possibilities for modifying thermal insulation polyurethane foams. Full article

Foam–CO₂ EOR Flooding is not very successful if unaccompanied by foam stabilizers such as nanoparticle fly ash (NFA). This study was conducted to determine the effect of NFA on foam stability by considering particle characteristics using the Bulk Foam Method as an additional condition. The test resulted in half-life times, which showed that in the absence of NFA, when oil was added, it was 211.5 s, and in salinity conditions, it was 232.5 s. This succeeds in improving half-life times to 226 s (with oil) and 241.5 s (with salinity) by adding NFA-Type F. For further research, conducting tests using reservoir conditions is recommended. Full article

Achieving efficient electrocatalytic oxidation of cellulose-derived biomass is a pivotal strategy for advancing bioenergy utilization and achieving carbon neutrality. This study addresses the challenges of low conversion efficiency caused by cellulose’s high crystallinity and excessive energy consumption in conventional processes by proposing a novel integrated system combining solid heteropoly acid catalytic pretreatment and electrocatalytic oxidation. By preparing the (C₁₆TA)H₂PW solid acid catalyst, we successfully achieved hydrolysis of microcrystalline cellulose under 180 °C for 60 min, attaining a glucose yield of 40.1%. Furthermore, a non-noble metal electrocatalyst system based on foam copper (CuF) was developed, with the Co₃O₄/CuF electrode material demonstrating a Faradaic efficiency of 85.3% for formate production at 1.66 V (vs. RHE) in 1 mol L⁻¹ KOH electrolyte containing the pretreated cellulose mixture, accompanied by a partial current density of 153.2 mA cm⁻². The mechanism study indicates that hydroxyl radical-mediated C-C bond selective cleavage dominates the formate generation. This integrated system overcomes the limitations of poor catalyst stability and low product selectivity in biomass conversion, offering a sustainable strategy for green manufacturing of high-value chemicals from cellulose. Full article

With increasing natural gas processing demands, triethylene glycol (TEG) in dehydration systems becomes contaminated by gas-carried impurities, leading to problematic foaming, degradation, and significant glycol losses that compromise operational economics, pipeline integrity, and product quality. To systematically investigate impurity effects, we conducted comprehensive single-factor TEG regeneration experiments simulating field conditions. Through precise measurements of foaming height, defoaming time, and interfacial tension, we established clear correlations between impurity types and TEG foaming characteristics. Our results demonstrate a distinct hierarchy of foaming influence: chemical additives > solid impurities > water-soluble inorganic salts > MDEA > hydrogen sulfide > hydrocarbons. Chemical additives showed the most pronounced effect on surface tension, reducing it to 31.1 mN/m at 1500 mg/L. Water-soluble inorganic salts affected foaming through combined decomposition and crystalline morphology effects, ranked as MgCl₂ > NaHCO₃ > KCl > NaCl > Na₂SO₄ > CaCl₂ (MgCl₂ achieving 33.8 mN/m at 2000 mg/L). Solid impurity impacts correlated strongly with particle morphology (CaCO₃ > Fe₂O₃ > CaSO₄ > ZnO > CuO > Al₂O₃ > FeS), stabilizing at 1.5 mg/L. Hydrocarbons showed negligible influence, while hydrogen sulfide and MDEA caused only minor surface tension reductions with limited foaming effects. Based on these findings, we propose targeted mitigation strategies for industrial implementation. Full article

In recent years, the increasing frequency of building fires has highlighted the limitations of traditional polymeric materials due to their inadequate fireproof performance. Ceramifiable polymer composites have emerged as a promising alternative by incorporating ceramic-forming fillers that create rigid ceramic-like structures through high-temperature eutectic reactions, offering exceptional thermal insulation and fireproof properties. These composites maintain structural integrity under fire exposure through sufficient mechanical strength retention. The effects of several ceramifiable inorganic fillers (CIFs) on the properties of polydimethylsiloxane (PDMS) foams were systematically investigated in this study. The research demonstrated that fillers with better matrix compatibility significantly enhance the foaming quality, mechanical performance, and fireproof capabilities. Notably, the CaCO₃-filled PDMS foam composite (CPF-Ca) demonstrates exceptional foaming characteristics with 84% porosity and a remarkably low density of 0.36 g/cm³. The material achieves tensile and compressive strengths of 0.22 MPa and 0.84 MPa, representing 22% and 127% enhancements, respectively, compared to pure PDMS foam (PPF). Regarding the ceramic conversion capability, the sintered residue of CPF-Ca maintains a compressive strength of 4.39 MPa under high-temperature conditions. This composite material exhibited superior fireproof performance, successfully withstanding a butane torch for 300 s without penetration while maintaining a remarkably low backside temperature of merely 83.6 °C. Full article

Conventional techniques for incorporating active ingredients into polymeric matrices are accompanied by certain disadvantages, primarily attributable to the inherent characteristics of the active ingredient itself, including its sensitivity to temperature. A potential solution to these challenges lies in the utilization of supercritical carbon dioxide (scCO₂) for the formation of polymeric foam and the incorporation of active ingredients, in conjunction with the encapsulation of inclusion complexes (ICs), to ensure physical stability and augmented bioactivity. The objective of this study was to assess the impact of IC impregnation and subsequent foam formation on PLA films and PLA/PBAT blends that had been previously impregnated. The study’s methodology encompassed the formation and characterization of ICs with caffeic acid (CA) and β-cyclodextrin (β-CD), along with the thermal, structural, and morphological properties of the resulting materials. Higher incorporation of impregnated IC into the PLA(42)/PBAT(58) blend was observed at 12 MPa pressure and a depressurization rate of 1 MPa/min. The presence of IC, in addition to a lower rate of expansion, contributed to the formation of homogeneous cells with a size range of 4–44 um. On the other hand, the incorporation of IC caused a decrease in the crystallinity of the PLA fraction due to the interaction of the complex with the polymer. This study makes a significant contribution to the advancement of knowledge on the incorporation of compounds encapsulated in β-CD by scCO₂, as well as to the development of active materials with potential applications in food packaging. Full article

In this study, a sulfur-doped cobalt–iron catalyst (CoFeS/NF) was synthesized on a nickel foam (NF) substrate via a facile one-step electrodeposition method, and its performance in urea electrolysis for hydrogen production was systematically investigated. Sulfur doping induced significant morphology optimization, forming a highly dispersed nanosheet structure, which enhanced the specific surface area increase by 1.9 times compared with the undoped sample, exposing abundant active sites. Meanwhile, the introduction of sulfur facilitated electron redistribution at the surface modulated the valence states of nickel and cobalt, promoted the formation of high-valence Ni³⁺/Co³⁺, optimized the adsorption energy of the reaction intermediates, and reduced the charge transfer resistance. Electrochemical evaluations revealed that CoFeS/NF achieves a current density of 10 mA cm⁻² at a remarkably low potential of 1.18 V for the urea oxidation reaction (UOR), outperforming both the undoped catalyst (1.24 V) and commercial RuO₂ (1.35 V). In addition, the catalyst also exhibited excellent catalytic activity and long-term stability in the total urea decomposition process, which was attributed to the amorphous structure and the synergistic enhancement of corrosion resistance by sulfur doping. This study provides a new idea for the application of sulfur doping strategy in the design of multifunctional electrocatalysts, which promotes the coupled development of urea wastewater treatment and efficient hydrogen production technology. Full article

The chemical looping reforming of methane using an SrFeO₃ oxygen carrier to produce synthesis gas from solar energy was experimentally investigated and validated. High-temperature solar heat was used to provide the reaction enthalpy, and therefore the methane feedstock was entirely dedicated to producing syngas. The two-step isothermal process encompassed partial perovskite reduction with methane (partial oxidation of CH₄) and exothermic oxidation of SrFeO_3-δ with CO₂ or H₂O splitting under the same operating temperature. The oxygen carrier material was shaped in the form of a reticulated porous foam structure for enhancing heat and mass transfer, and it was cycled in a solar-heated tubular reactor under different operating parameters (temperature: 950–1050 °C, methane mole fraction: 5–30%, and type of oxidant gas: H₂O vs. CO₂). This study aimed to assess the fuel production capacity of the two-step process and to demonstrate the potential of using strontium ferrite perovskite during solar cycling for the first time. The maximum H₂ and CO production rates during CH₄-induced reduction were 70 and 25 mL/min at 1000 °C and 15% CH₄ mole fraction. The increase in both the cycle temperature and the methane mole fraction promoted the reduction step, thereby enhancing syngas yields up to 569 mL/g during reduction at 1000 °C under 30% CH₄ (778 mL/g including both cycle steps), and thus outperforming the performance of the benchmark ceria material. In contrast, the oxidation step was not significantly affected by the experimental conditions and the material’s redox performance was weakly dependent on the nature of the oxidizing gas. The syngas yield remained above 200 mL/g during the oxidation step either with H₂O or CO₂. Twelve successive redox cycles with stable patterns in the syngas production yields validated material stability. Combining concentrated solar energy and chemical looping reforming was shown to be a promising and sustainable pathway toward carbon-neutral solar fuels. Full article

It is crucial for energy storage devices to construct electrode materials with excellent performance. However, enhancing energy density and cycling stability for supercapacitors is a significant challenge. We successfully synthesized CoNi₂S₄@Ni(OH)₂ nanosheets on the surface of Ni foam substrate by a two-step hydrothermal approach. The obtained products exhibit a remarkable areal capacitance of 1534 F g⁻¹ at a current density of 1 A g⁻¹. Moreover, even after 10,000 cycles, the specific capacitance remains 90% of its initial value, highlighting the exceptional long-term stability and durability. Furthermore, an asymmetric supercapacitor (ASC) device incorporating the CoNi₂S₄@Ni(OH)₂ material shows remarkable electrochemical performance. It delivers an energy density of 58.5 mW h g⁻¹ at a power density of 2700 W kg⁻¹. The outstanding performance mainly arises from the selection of materials, the design of the structure, and the synergistic interaction between the materials. The result suggests that this material holds great potential as an energy storage material. Full article

The urea electro-oxidation reaction (UOR) is emerging as a new energy conversion technology and a promising method for alleviating water eutrophication problems. However, a rationally designed structure of the electrode materials is urgently required to achieve high UOR performance. Herein, P-doped MOF-derived Co₃O₄ nanowire arrays grown on nickel foam (P-Co₃O₄/NF) are successfully synthesized via the growth of Co-MOF and subsequent calcination followed by phosphorization treatment. Owing to the optimized electronic structure, the as-prepared P-Co₃O₄/NF composite exhibits much higher UOR electrocatalytic performance than the undoped Co₃O₄/NF sample. Beyond this, the meticulous structure of the one-dimensional nanowire arrays and the three-dimensional skeleton structure of nickel foam contribute to the enhanced electrocatalytic activity and stability toward UOR. As a result, the P-Co₃O₄/NF composite displays a low overpotential of 1.419 V vs. RHE at 50 mA cm⁻², a small Tafel slope of 82 mV dec⁻¹, as well as favorable long-term stability over 65,000 s in 1.0 M KOH with 1.0 M urea. This work opens a new avenue in designing non-precious electrocatalysts for high-performance urea electro-oxidation reactions. Full article

This research aims to facilitate informed decision-making to enhance building energy simulation, reduce costs, and minimize CO₂ emissions through building insulation enhancements employing BIM-based simulation. Architectural models of an apartment, a prevalent residential structure in Japan, were developed and examined under diverse insulation scenarios utilizing ArchiCAD 28. Five insulation substances were chosen based on existing guidelines to ensure conformity with local standards and were evaluated for their thermal and environmental properties: Cellulose Fiber, Glass Wool, Urethane Foam, Phenolic Board, and Rock Wool for evaluation based on thermal and environmental properties. The simulation parameters were aligned with Japan’s energy efficiency standards and climate conditions. The factors addressed encompass energy performance evaluation, economic viability, and CO₂ emissions. Simulation findings highlight Urethane Foam as the most effective and environmentally friendly building insulation material. This study provides valuable perspectives for property owners, building designers, and contractors, offering a framework for insulation enhancement choices that optimizes sustainable construction, reduces environmental impact, and enhances cost-effectiveness through the implementation of BIM-based simulation. Full article

Flexible pavements stand out as the most commonly used worldwide, compared to rigid and composite pavements, owing to their versatility and widespread application. The use of hot mix asphalt (HMA) in flexible pavements causes significant environmental concerns due to high CO₂ emissions and energy consumption, whereas warm mix asphalt (WMA) technologies have gained popularity in recent decades, offering a more sustainable alternative by enabling asphalt production at lower temperatures. WMA technologies can be categorized into three main groups: foaming, organic additives, and chemical additives, with each offering distinct benefits for performance and environmental impact. One of the chemical additives used in WMA production is Cecabase RT BIO10. In this study, virgin bitumen with 50/70 penetration was modified by adding Cecabase RT BIO10 at four levels: 0%, 0.3%, 0.4%, and 0.5% by weight. The experimental design employed a Taguchi L16 orthogonal array to systematically evaluate the effects of various factors on modified bitumen performance. Binders were prepared at four temperatures (110 °C, 120 °C, 130 °C, and 140 °C), four mixing durations (15, 20, 25, and 30 min), and four mixing speeds (1000, 2000, 3000, and 4000 rpm), enabling an efficient analysis of each parameter’s impact. The prepared binders were subjected to a series of tests, including penetration, softening point, flash point, rotational thin film oven test (RTFOT), elastic recovery, Marshall stability, ultrasonic pulse velocity (UPV), and FTIR analysis. These tests were conducted to investigate the effects of various parameters and levels on the binder properties. Additionally, stiffness and seismic modules were evaluated to provide a more comprehensive understanding of the binder’s performance. The experiment results revealed that the penetration, elastic recovery percentage, and Marshall stability increased with increasing additive content while the softening point and RTFOT mass loss decreased. At a high service temperature of 40 °C, the stiffness modulus of the modified bitumen decreased slightly. At a low service temperature of −10 °C, it decreased further. Additionally, the incorporation of Cecabase RT BIO10 led to an increase in the seismic modulus. Through optimization using the Taguchi method, the optimal levels were determined to be a 0.4% Cecabase RT BIO10 ratio, 140 °C mixing temperature, 30 min mixing time, and 1000 RPM mixing speed. The optimal responses for each test were identified and integrated into a unified optimal response, resulting in a comprehensive design guide with 95% confidence level estimates for all possible level combinations. Full article

In this study, a novel slow-release material using recycled waste foamed polystyrene (WFPS) as the carrier was developed for the degradation of aniline-contaminated groundwater. Sodium persulfate (SPS) and zero-valent iron (ZVI) were embedded in WFPS, enabling the controlled and sustained release of reactive species. Systematic investigations were conducted to optimize the material’s composition and evaluate its performance under various conditions, including pH, initial aniline concentration, and the presence of common groundwater anions. The results revealed that the slow-release material effectively enhanced aniline degradation, achieving a maximum removal rate of 93.45% under flowing conditions. The degradation pathway was analyzed using GC-MS, identifying intermediates such as benzoquinone, hydroquinone, and dodecane, with eventual mineralization into CO₂ and H₂O. The material demonstrated robust performance, offering an efficient, cost-effective, and environmentally sustainable approach for in situ groundwater remediation. Full article

Mixed transition metal sulfides are promising materials for positive electrodes of asymmetric supercapacitors because they have a large potential for increasing the electrical characteristics of these devices. The paper presents the results of a study of a material based on spinel CuCoNiS_xO_4−x with both sulfide and oxide sublattices, prepared by a one-step hydrothermal method directly on nickel foam, forming an array of whiskers. Electrochemical studies showed that a positive electrode, CuCoNiS₂O₂, exhibited a high specific capacitance of 3612 F g⁻¹ at a current density of 1 A g⁻¹. The assembled asymmetric supercapacitor with activated carbon as a negative electrode achieved a specific capacitance of 133.5 F g⁻¹ at 1 A g⁻¹ and a potential window of 1.7 V. Its energy density was 53.6 Wh kg⁻¹ at a power density of 805 W kg⁻¹ and the power density reached 17,000 W kg⁻¹ at an energy density of 18.9 W h kg⁻¹. The assembled device exhibits 52% of capacitance retention after the 20,000 cycles at a current density of 10 A g⁻¹ with 97% coulombic efficiency. These results demonstrate that the CuCoNiS_xO_4−x system is competitive with other quaternary transition metal sulfides, and this type of spinel is a perspective electrode material for high-performance supercapacitors. Full article