Sustainable Materials and Technologies最新文献

Developing efficient, stable, and low-cost metal electrocatalysts for hydrogen evolution reaction (HER) is significant for clean energy conversion technology. Regulating the adsorption energy of H intermediates by modulating the electronic structure of the active sites of the electrocatalyst for approximating the equilibrium potential is of primality importance to overcoming the kinetic sluggishness of the HER, yet still represents a great challenge. Herein, we have reported a NiCo alloy electrocatalyst supported by an N-doped carbon dodecahedral substrate with a strong electron coupling between the NiCo alloy and NC to improve the obstacles of both activity and stability for HER. Benefiting from the above electron coupling effect, the Ni₁Co₂/NC catalyst exhibits enhanced HER activity and stability in an acid electrolyte. Specifically, the Ni₁Co₂/NC exhibits enhanced acid HER activity with a low overpotential of 114.7 mV at 10 mA cm⁻² and robust stability with negligible activity decay after 5000 cycles, which are superior to its counterpart. Theoretical calculations revealed that the electron coupling between the NiCo alloy and NC could effectively moderate the electronic states of NiCo alloy, dramatically decreasing the free energy for H adsorption and leading to optimal adsorption/desorption of *H, thereby promoting the overall HER kinetics. This study provides a new perspective on constructing catalysts of HER with low-cost, well-designed structures and superior performance for clean energy conversion technology.

Photoelectrocatalyst materials catalyze chemical reactions using solar light and an electric field. They have garnered interest due to their potential for sustainable energy conversion and environmental applications. Photoelectrocatalysts have demonstrated moderate magnetic properties, making them potential candidates for practical applications. This review aims to highlight various methods of synthesis, functionalization, and environmental applications of photoelectrocatalysts. The present work also describes different methods for synthesizing photoelectrocatalysts such as sol-gel, hydrothermal/solvothermal, chemical vapour deposition, electrochemical methods, thermal decomposition, chemical bath deposition, co-precipitation, impregnation, and heat treatment. Furthermore, various characterization techniques such as TEM, SEM, STM, XRD, PL, XPS, ET, EIS, BET, RS, ESR, etc., have been summarized and discussed. To enhance the properties and applications of photoelectrocatalysts, functionalization has also been discussed. Additionally, numerous uses such as water splitting, photocatalysis, environmental remediation, carbon dioxide reduction, energy storage, sensor technology, water purification, biomedical applications, etc., have been explored, covering a broad range of fields, and highlighting the versatility of photoelectrocatalysts across various sectors. Likewise, various experimental factors that affect the structure-property relationship of the materials have also been elaborated. Furthermore, challenges and future suggestions have been discussed in the concluding section to provide guidance for researchers. Given its simplicity and conciseness, it is hoped that this review will be equally helpful for researchers and academics interested in the field of photoelectrocatalysts.

The use of fluorinated gases (F-Gases) in the refrigeration industry is subjected to increasingly restricted laws, such as the F-Gas regulation 517/2014 in Europe, due to their high global warming potential (GWP). Currently, there is a lack of standardized recovery technologies, so most of the F-gases used to be incinerated at the end of their life cycle. This is contrary to the principles of circular economy and development of sustainable processes, which should consider the recycling of these gases. The difficult separation of F-Gases blends might have a solution on the use of Deep Eutectic Solvents (DES) as green absorbents. In this work, the performance of a DES was assessed for the recovery of pentafluoroethane (R-125) and difluoromethane (R-32) from the commercial refrigerant R-410A combining a dual approach based on the experimental measurement of the F-Gases absorption in the DES and on process simulation using Aspen Plus. The environmental impacts of the designed recovery process (circular economy scenario) were examined using a life cycle assessment (LCA) approach and it was compared to the environmental impacts of the industrial manufacture of R-125 (lineal economy scenario). In comparison to the conventional R-125 production, the results of the proposed recovery process revealed a significant reduction in the environmental impacts between 92 and 99% with a recovery of R-125 of 76.7%, acceptable for its further reuse (purity of 98% w/w). The results of this work could pave the way for developing innovative F-Gases recovery technologies using DES, which can contribute to reduce the environmental impacts of these compounds via circular economy strategies.

In this study, carbon cloth (CC) was enrobed with a TiO₂ layer (CC@TiO₂) and then decorated with poly(3,4-ethylenedioxythiophene) (PEDOT, CC@TiO₂-PEDOT). The XRD, Raman, XPS, and EDS results confirmed the successful preparation of the targeted materials, and SEM images revealed the targeted morphology. According to the UV–vis and PL analysis, the CC@TiO₂-PEDOT exhibits wide and strong photoabsorption across the UV–vis spectrum, and the photogenerated charge carriers have a long lifespan and low recombination rate. The photocatalytic assessment revealed that CC@TiO₂-PEDOT was more efficient than CC@TiO₂ and CC@PEDOT in degrading both benzotriazole and 2-hydroxybenzothiazole. However, 2-hydroxybenzothiazole was more stable than benzotriazole. The superoxide anion radicals, holes, and/or hydroxyl radicals of CC@TiO₂-PEDOT played pivotal roles in the photocatalytic degradation of benzotriazole. After the photocatalytic process, the benzotriazole solution was safe to use. The CC@TiO₂ and CC@TiO₂-PEDOT exhibited a superior performance as a potential cathode for vanadium redox flow batteries (VRFBs) and effectively mitigated the parasitic influence of the hydrogen evolution reaction (HER). CC@TiO₂ and CC@TiO₂-PEDOT displayed significantly smaller peak separation of 94 and 62 mV, at a scan rate of 5 mV/s, respectively, and a higher suppression for HER compared to CC or CC@PEDOT. The performance of the CC@TiO₂ and CC@TiO₂-PEDOT electrodes manifests their high reversibility for the V(II)/V(III) redox reaction. This research underscores the multifaceted potential of CC@TiO₂-PEDOT as a promising material for addressing water purification challenges and advancing VRFBs for sustainable energy applications.

Compared with traditional binary ion electrolytes, single-ion electrolytes have higher ion migration number and can avoid concentration polarization. In this work, single proton hydrogel electrolytes were prepared by one-step free radical polymerization of acrylamide and 2-acrylaminoamido-2-methyl-1-propane sulfonic acid in ethylene glycol (EG)/water binary solvent. The electrolyte possesses good mechanical strength and excellent anti-freezing ability. A high conductivity of 1.28 mS cm⁻¹ at −40 °C is achieved by adjusting monomer ratio and EG content. The proton hopping along the ion channel formed by the anionic polymer chain and the Grotthuss transport are responsible for the high conductivity. An extremely high ion migration number of 0.87 is obtained. The fixed anionic group endows the hydrogel electrolyte with good anticorrosion ability. The hydrogel electrolyte assembled supercapacitor (SC) exhibits excellent electrochemical performance in a wide temperature range from −40 °C to 60 °C and can be stored at −30 °C for 10 months without capacitance attenuation. The capacitance retention rate of the SC is as high as 92% after 15,000 cycles at both room temperature and − 40 °C. The single proton hydrogel electrolyte provides a new route for the further development of storage device based proton transport.

High-activity, stable, and high-efficiency bifunctional Pt-based catalysts that promote oxygen reduction reactions (ORRs) and hydrogen evolution reactions (HERs) are urgently needed to meet the ever-intensifying energy demands. In this paper, we propose a novel strategy for enhancing an electrocatalyst's durability using a high-porosity and abundantly nitrogen-doped carbon framework (NDCF) support derived from ZIF-8. PtNi alloy nanoparticles (NPs) surrounded by dense dual single atoms (SAs) of Pt and Ni were immobilized in a porous NDCF matrix (PtNi_SA-NPs/NDCF), synergistically exhibiting bifunctional catalytic activity and durability toward ORR and HER. Under acidic conditions, the PtNi_SA-NPs/NDCF exhibits a half-wave potential of 0.91 V and a favorable 4-electron pathway for ORR. It also displays an overpotential of 24.7 mV at a current density of 10 mA cm⁻² and a mass activity of 6.1 A mg_Pt⁻¹ (at 40 mV), indicating ultrahigh electrocatalytic activity for HER. Critically, the PtNi_SA-NPs/NDCF showed remarkable durability over 10,000 CV cycles, reducing ORR's half-wave potential by only 4 mV and HER's overpotential by a mere 6 mV at 10 mA cm⁻². We attribute this enhancement in durability to the stable graphitic carbon shell encapsulating the PtNi alloy NPs and the enrichment of pyridinic-N coordination by the NDCF support.

Highly efficient synergetic photocatalysts based on graphitic carbon nitride (g-C₃N₄) and cadmium sulfide (CdS) semiconductors with 2D/0D micro/nanostructure were successfully prepared by easy scalable mechanochemical method and investigated. An in-depth study of electrons' binding energy of semiconductors and their influence on the photocatalytic activity of nanocomposites has been performed. The synthesized materials were applied for the photodegradation of Orange II dye and photocatalytic hydrogen evolution. The obtained experimental results revealed that nanocomposite with 20 wt% of g-C₃N₄ and 80 wt% of CdS is able to completely decompose Orange II molecules after two hours of visible light irradiation. The mechanism and pathways of photocatalytic reactions have been proposed. The nanocomposite composed of 60 wt% g-C₃N₄ and 40 wt% CdS, decorated by a platinum (Pt) co-catalyst, demonstrated the peak hydrogen evolution rate (HER) of 2254.54 μmolh⁻¹ g⁻¹ after 4th hour of solar light illumination. This remarkable achievement, with an apparent quantum efficiency (AQE) of 2.0%, occurred on the fourth hour of solar light irradiation. Furthermore, under continuous visible light irradiation, the sample with the same composition is capable of producing hydrogen. The peak HER rate recorded was 246.14 μmolh⁻¹ g⁻¹ (AQE = 0.44%) after 2.5 h, and this remained consistently the same throughout the entire duration of the process.

Phenol formaldehyde foams, extensively utilized in wide range of applications face challenges due to depleting petroleum resources and adverse environmental concerns. This study explores a promising shift to biobased alternatives, specifically investigating the use of Kraft lignin (KL) by replacing about 10 to 50% phenol content to synthesize open-cell hydrophilic phenolic foams. The produced foams undergo comprehensive testing to evaluate wetting properties, porosity, mechanical strength, and biodegradation potential. Remarkably, foams with a high percentage of Kraft lignin exhibit outstanding physical and wetting characteristics. Notably, substituting 50% of phenol with KL gave rise to a foam with a density of 40 kg/m³, open cell porosity of about 100%, water absorption capacity of 2100%, and an average water uptake rate of 0.9 cm³/s. Furthermore, these lignin-substituted foams display enhanced biodegradability compared with their petroleum-based counterparts. The foam with the 40% phenol substitution exhibits the highest weight loss of approximately 68% in 15 days during the biodegradation test. The biodegradation was further confirmed using scanning electron microscopy and FT-IR analysis of the degraded samples.

The blending degree, dominated by the diffusion process between virgin and rejuvenated asphalt, profoundly affects the performance of recycled mixtures. However, research on the blending degree in Warm Mix Asphalt (WMA) containing Styrene-Butadiene-Styrene-modified asphalt (SBSMA) mixtures remains relatively underexplored despite its significant impact on pavement performance. To this concern, a predictive model for characterizing the diffusion behavior of the WMA modified SBSMA and synchronous rejuvenated SBSMA was developed based on the free volume theory, which was validated by the pulsed field gradient nuclear magnetic resonance test. Based on the predicted diffusion coefficients, the influences of WMA additives, rejuvenator types, and temperatures on diffusion behavior were systematically investigated. Results indicated that the diffusion coefficients were affected by the interaction of WMA additives, rejuvenator types, and temperatures. The presence of the WMA additive and the increase in diffusion temperature were able to improve the blending degree by increasing the diffusion coefficient. Rebalancing the unstable colloidal structure of SBSMA can enhance the diffusion coefficient of the WMA modified SBSMA twice than that of untreated one. After further reconstruction of small SBS fragments into the triblock copolymers, the blending between the WMA modified SBSMA and synchronous rejuvenated SBSMA was completed in the form of mutual diffusion, showing the highest diffusion coefficients (10⁻⁷).

Abstract

P2-type Na_2/3Ni_1/3Mn_2/3O₂ (NNM), a promising candidate cathode material for advanced sodium ion batteries, has been extensively investigated in terms of its excellent electrochemical performance, straightforward preparation process, cost-effectiveness, and similarities to well-established Li-ion counterparts. However, the specific capacity, rate capability and cycling stability are severely dragged down by irreversible phase transitions, Na⁺/vacancy ordering, and interface deterioration. Research progress related to modification strategies for boosting the performance of P2-NNM cathodes in SIBs is provided. The perspectives and development directions for the optimization strategies for NNM cathodes are also presented. This review systematically and comprehensively elaborates the modification strategies for NNM cathodes, furnishing a positive guideline for designing and optimizing P2-NNM cathodes for the burgeoning commercial SIBs market.