Separation Efficiency Research Articles

Ultrahydrophilic Inorganic Nanosheet-Based Nanofiltration Membranes for High Efficiency Separations of Inorganic Salts and Organic Dyes.

Two-dimensional (2D) inorganic nanomaterials have garnered extensive attention in the fabrication of inorganic nanofiltration membranes due to their unique structures and properties. In this study, we developed a facile process for fabricating large-scale ultrahydrophilic nanofiltration membranes using layered titanate H1.07Ti1.73O4·nH2O nanosheets (HT-ns). A drying deposition process was used to fabricate HT-ns membranes on a poly(tetrafluoroethylene) (TF) substrate. To enhance the bonding strength between the substrate and the deposited HT-ns membrane, the substrate surface was modified with a Cu2+-adsorbed silane monomolecular layer, connecting a negatively charged HT-ns membrane and a positively charged substrate surface. The fabricated HT-ns membrane exhibited an excellent rejection performance for inorganic salts and dye molecules. The ultrahydrophilicity of HT-ns membrane with a low water contact angle of 31° results in an ultrafast water permeance, which is approximately 6 times higher than that of a simple graphene-based nanofiltration membrane. The results open a new avenue to a new category of ultrahydrophilic nanofiltration membranes.

Fabrication of a novel Ag2S-ZnS/ZIF-8 hollow heterojunction by in-situ formation of Ag2S and ZnS on ZIF-8 with enhanced tetracycline degradation performance

Currently, antibiotics are extensively utilized in the pharmaceutical industry to assist humans and animals in combating various infectious diseases. The extensive use of various antibiotics enhances the quality of life. However, it can also have negative effects on the environment and human health, including water pollution and the rise of antibiotic-resistant microorganisms. To date, antibiotics have been detected in rivers, groundwater, and even drinking water. There is an urgent need to design and develop advanced materials for the remediation of antibiotics present in our environment. In this paper, we successfully synthesized a novel Ag2S-ZnS/ZIF-8 hollow heterojunction via facile sulphuration and solvothermal methods. This heterojunction was employed as a catalyst for the degradation of tetracycline (TC) in water under UV and visible light irradiation. The physicochemical properties of the as-synthesized catalysts were thoroughly analyzed using XRD, EDS, SEM, BET, XPS, TEM, ESR, UV–vis techniques. The results demonstrate that Ag2S-ZnS/ZIF-8 displays enhanced photocatalytic activity for TC degradation no matter under visible or UV light irradiation. After 10 min of UV light irradiation, its photocatalytic degradation efficiency was achieved 92.74 %. Additionally, Ag2S-ZnS/ZIF-8 was able to degrade 92.14 % of TC (visible light, with 35 min). The corresponding kinetic rate constant of Ag2S-ZnS/ZIF-8 is 0.145 min−1 (UV light) and 0.043 min−1 (visible light), respectively. Furthermore, Ag2S-ZnS/ZIF-8 also shown excellent stability for the degradation of TC in the presence of visible light. This is a result of its high specific surface area, superior photocurrent and efficient separation of photo-generated electrons-hole pairs. Apart from this, the photocatalytic degradation mechanism of TC over Ag2S-ZnS/ZIF-8 is discussed in detail.

Fabrication of a ZIF-8/PVA Membrane on PVDF Fiber by Spray for the Highly Efficient Separation of Oil-in-Water Emulsions.

In human life and production, excessive oily wastewaters containing detergents are produced and discharged, causing severe environmental pollution and water resource problems. A metal-organic framework (MOF)-based membrane is an economical and environmentally friendly tool for emulsion separation but is limited by a complex preparation process and poor flexibility. Herein, we developed a simple method to synthesize a MOF-based mixed-matrix membrane (MMM) by spray and fabricated the membrane on poly(vinylidene fluoride) (PVDF) fibers via postdeposition and in situ growth manners. The prepared ZIF-8/PVA MMMs have uniform distribution of ZIF-8 particles and poly(vinyl alcohol) (PVA) on the PVDF fibers. PVA improved the adhesion between the ZIF-8 particles and between the MOF layer and PVDF fiber, endowing the separation membrane with high flexibility and bendability. The prepared ZIF-8/PVA membrane exhibited hydrophilicity and underwater superoleophobicity, which showed high separation efficiency and considerable water flux for emulsions, emulsion containing dye, and surfactant-stabilized emulsion. In addition, the fabricated ZIF-8/PVA/PVDF fibers exhibited good antifouling property and flexibility and can maintain stable separation efficiency after working several times and even under bending, demonstrating the stability and potentiality of the ZIF-8/PVA/PVDF fibers in practical applications. This work paves a new avenue for the synthesis and application of MOF-based MMMs.

Rational construction p-n heterojunction Ni(OH)2/NiS2 on g-C3N4 nanosheet to promote the charge carriers separation efficiency for boosting photocatalytic hydrogen evolution

The Ni(OH)2/NiS2/g-C3N4 hybrid with sandwich-like structure was successfully designed and synthesized through a solvothermal and condensation reflux method. Furthermore, it should be noted that the p-type Ni(OH)2 was in situ generated on the surface of the n-type NiS2, because the Ni2+ of the Ni(OH)2 came from the NiS2. Therefore, the p-n heterojunction was constructed between the interface of the Ni(OH)2 and NiS2 in the hybrid. Furthermore, the results revealed the optimized Ni(OH)2/NiS2/g-C3N4 hybrid displayed superior H2 evolution property than that of the g-C3N4, NiS2/g-C3N4, and Ni(OH)2/g-C3N4 illuminating with visible-light or simulated-sunlight. The apparent quantum yield (AQY) of Ni(OH)2/NiS2/g-C3N4-6 % at 360, 380 and 400 nm were 1.65 %, 1.31 % and 1.05 %, respectively. Moreover, the resultant Ni(OH)2/NiS2/g-C3N4-6 % hybrid both displayed satisfactory photochemistry durability. Besides this, according to the microstructure and photoelectric property characterizations, theoretical calculation, and in situ XPS test, the promoted H2 evolution property of the ternary catalyst was profit from the synergy impact of the particular sandwich-like structure, and p-n heterojunction. Because they could memorably boost the carriers’ separation efficiency, and offer abundant active sites for H2 production.

Enhanced solar-powered H2 production from water splitting and sustainable wastewater treatment using interface-engineered ZnIn2S4/TiO2/Ti3C2 S-scheme heterocatalyst

Developing efficient photocatalysts that can degrade persistent antibiotics in water bodies and generate clean H2 through water splitting is crucial for environmental and energy sustainability. This study introduces an advanced hierarchical ZnIn2S4/TiO2/Ti3C2 (ZIS/TO/TC) heterocatalyst for the efficient removal of amoxicillin (AXC) from wastewater and the production of H2 through water reduction process under simulated solar illumination. The ZIS/TO/TC hybrids were fabricated via an in situ hydrothermal process, resulting in a hierarchical 3D structure that capitalizes on the complementary properties of each component. The design of the S-scheme heterojunction significantly enhances charge separation and transfer efficiency, offering improvements over traditional type-II or Z-scheme mechanisms. Notably, the optimized ZIS10/TO/TC hybrid catalyst demonstrated remarkable activity, achieving 100 % AXC degradation and excellent mineralization within 90 min, along with an H2 production rate of 4104 μmol h−1 g−1, significantly outperforming the individual components and exceeding previously reported efficiencies. The outstanding performance of the ZIS10/TO/TC hybrid is attributed to its enhanced light absorption properties, synergistic interactions among the ZIS, TO, and TC MXene, and the efficient S-scheme charge transfer mechanism, which facilitates effective charge separation and transfer while preserving the strong reducing and oxidizing capabilities of the components. Additionally, the ZIS10/TO/TC hybrid exhibited excellent stability over multiple photocatalytic tests, emphasizing its potential for practical applications. Therefore, this research demonstrates an advanced and highly efficient hybrid photocatalyst that offers a promising and sustainable solution for both integrated water treatment and renewable energy generation.

Efficient adsorption and selective separation of high value-added chemicals from simulated expired energy drinks by metal-organic frameworks

Expired energy drinks contain a certain amount of high-value chemicals, such as caffeine, that possess biological activity. The recovery and recycling of these valuable chemicals plays a crucial role in promoting the achievement of carbon emission reduction goals. In this work, 11 kinds of water-stable MOFs with different pore channel structure were synthesized and used for the first time to adsorb caffeine, nicotinic acid, or taurine from water. It has been found that the size effect of the topological structure of MOF adsorbents is the fundamental factor governing their adsorption performance. The optimized adsorbent UiO-67 exhibits excellent adsorption performance for caffeine and nicotinic acid, with respective adsorption capacities of 830 mg/g and 583 mg/g. The investigated MOF has a very low adsorption capacity for taurine (48 mg/g); therefore, selective separation of caffeine/taurine and nicotinic acid/taurine was achieved. The adsorption process can be accurately described by both the Langmuir model and pseudo-second-order model. Adsorption mechanism reveals that the main driving forces of the adsorption process are π-π interaction between UiO-67 and CN in caffeine, as well as hydrogen bonding interactions between the N atom of caffeine’s two CO groups and μ-OH of UiO-67.

Z-scheme heterojunction enhanced photocatalytic performance for CO2 reduction to CH4.

Due to the high charge separation efficiency leading to high photocatalytic activity, there has been significant interest in enhancing the charge separation ability of photocatalysts by controlling the heterojunction structure. To investigate the effect of the heterojunction structure on the photocatalytic performance of composite catalysts and understand its corresponding mechanism, a Z-scheme ZnFe2O4/ZnO/CdS heterojunction was constructed using the ultrasound method and used for CO2 photoreduction. The Z-scheme heterojunction catalyst demonstrates elevated photocatalytic and charge separation efficiencies. Specifically, the conversion rate for the photocatalytic conversion of CO2 to CH4 reaches 105.9 μmol g-1 h-1, surpassing that of the majority of previously reported semiconductor photocatalysts like ZnFe2O4/CdS. This research offers a fresh perspective on the development of innovative heterojunction photocatalysts and broadens the utilization of ternary composite materials in CO2 photoreduction.

Models for analysing the economic impact of ore sorting, using ROC curves

The past decade has seen a renewed possibility of using machine learning algorithms to solve a large collection of problems in several fields. Data acquisition for mining operations has increased with the growth in sensor-based technologies, and therefore the amount of information available for mining applications has dramatically increased. Ore sorting equipment is available for separating ore from waste based on differences in physical properties detected by a real-time analyser. The separation efficiency depends on the contrast in these properties. In this study we investigate the application of machine learning models trained using data from the output of a dual-energy X-ray ore sorting apparatus at a gold mine. The particles were first hand-sorted into ore and gangue classes based on their mineralogical composition. Classification models were then used to help decide the balance between the number of true and false positives for ore in the concentrate, with a view to economic parameters, using their receiver operator characteristic (ROC) curves. The results showed AUC (area under the ROC curve) scores of up to 0.85 for the classification models and a maximum reward condition Fpr/Tpr around 0.5/0.9 for a simplified economic model.

S‐Scheme MnO2/Co3O4 Sugar‐Gourd Nanohybrids with Abundant Oxygen Vacancies for Efficient Visible‐Light‐Driven CO2 Reduction

AbstractConverting CO2 to carbon‐based fuels using solar energy via photocatalysis is a promising approach to boost carbon neutrality. However, the solar‐to‐chemical conversion efficiency is hampered by interconnected multiple factors including insufficient light absorption, low separation efficiency of photogenerated carriers as well as complex and sluggish surface reaction kinetics. Herein, we incorporate MnO2 nanowires and Co3O4 hollow polyhedrons with abundant oxygen vacancies (VO) into MnO2/Co3O4 sugar‐gourd nanohybrids for boosting CO2 photoreduction. The MnO2/Co3O4 nanohybrids not only display strong absorption in the visible–near infrared region, but also facilitate the separation of photogenerated carriers in terms of S‐scheme transfer pathway, supplying abundant electrons for CO2 reduction reaction. Furthermore, the presence of VO enhances the separation efficiency of photogenerated carriers and promotes the chemical adsorption to CO2 molecules. In addition, the interfacial electronic interaction between MnO2 and Co3O4 also contributes to the chemical adsorption and activation to CO2. Owing to the synergy of S‐scheme transfer pathway and VO, the MnO2/Co3O4 hybrids exhibit greatly enhanced photocatalytic activity towards CO2 reduction under the irradiation of visible light in comparison with bare MnO2 and Co3O4, delivering a CO evolution rate of 15.9 umol g−1 h−1 with a 100 % selectivity.

Evaluation of a simultaneous approach to concentrate and preserve bioactive compounds with distinct polarities by employing supramolecular solvents (SUPRAS)

Supramolecular solvents (SUPRAS) have attracted attention as eco-friendly and highly effective solvents that can be tailored to solubilize compounds with distinct polarities. This study investigated the SUPRAS/equilibrium solution systems’ (SUPRAS-EqS) capacity to concentrate and preserve bioactive compounds through simultaneous solvent production and a liquid–liquid separation method. For this, β-carotene, quercetin, and curcumin were evaluated as molecular probes. SUPRAS-EqS systems were produced with octanoic acid (5 %, v/v), ethanol (20–––35 %, v/v), and acidified water (75–––60 %, v/v) and characterized concerning SUPRAS phase formation and their composition. Moreover, the SUPRAS phase’s ability to preserve these compounds during thermal exposure was evaluated at 313.15 K, 323.15 K, and 333.15 K and compared with an ethanolic medium. The outcomes demonstrated the formation of spherical supramolecular aggregates (10 to 20 μm), where the size of coacervates increased proportionally with the ethanol concentration. Concerning the separation efficiency provided by the SUPRAS phase, all compounds exhibited values superior to 83 %, and the systems produced with 22.5 % ethanol for quercetin and curcumin, and 27.5 % ethanol for β-carotene, presented the highest partition coefficient values. The SUPRAS phase promoted a more suitable environment to preserve the bioactive compounds than ethanol, and quercetin exhibited the highest half-life time values. Curcumin displayed the strongest activation energy in both the SUPRAS phase (48.88 kJ/mol) and the ethanol media (54.50 kJ/mol), indicating its high temperature dependence compared to the other compounds. These findings highlight the SUPRAS phase capacity to concentrate and stabilize bioactive compounds individually with different polarities.

Effects of peracetic acid delignification on hemicellulose extraction by dimethyl sulfoxide

Extracting high-purity and structurally intact hemicelluloses from lignocellulosic fibers is a prerequisite to reveal their structures and realize high-value utilization. Delignification is usually performed before hemicellulose extraction to break the covalent bonds between hemicelluloses and lignin for effective separations, but usually leads to toxic by-products and hemicellulose degradation. Peracetic acid (PAA) is an environmentally friendly oxidizing agent, which is more selective for delignification and has less effect on the primary structure of hemicelluloses. However, the yields and chemical structures of hemicelluloses extracted at different PAA delignification conditions are not clear, which greatly hinders its research and application. Consequently, the response surface methodology (RSM) was used in this study to optimize the process parameters of PAA delignification. With the increase of temperature or time, the yield of holocellulose decreases, and the hemicellulose yield increases first and then decreases. With the increase of delignification degree, the hemicellulose yield increases significantly. The degree of PAA delignification also has a significant effect on the chemical structures of extracted hemicelluloses; hemicellulose samples extracted from highly delignified holocelluloses have a higher xylose unit content, molecular weight (MW) and degree of substitution by acetyl groups (DSAc). The tert-butanol solvent exchange or ball milling treatments on holocelluloses significantly increase the hemicellulose yields, by avoiding the hornification and improving the accessibility of holocellulose. This study will provide theoretical and technical support for the efficient separation of hemicelluloses.

Efficient degradation of methylene blue and HCHO by nonmetallic B-doped g-C3N5: activity and mechanism analysis

To solve the pollution of natural water bodies by organic dyes and the exceeding of indoor HCHO standards caused by renovation, the study realized the band gap modulation of g-C3N5, a novel semiconductor photocatalytic material, by using H3BO3 as a source of nonmetallic B. The prepared B/g-C3N5 has shown excellent photocatalytic performance and stability for organic dye degradation in water bodies and indoor HCHO removal. The degradation rate of methylene blue (MB) reached 95% in 60 min of visible light, and the removal rate of HCHO reached 96.3% in 180 min of visible light. The MB and HCHO were efficiently degraded to small molecule inorganic compounds such as CO2 and H2O under the oxidation of active groups such as ·O2 − and h+. The doping of nonmetallic B realizes the efficient separation of e−-h+ of g-C3N5, improve the absorption performance of visible light, and broaden the spectral range significantly. The modulation of the g-C3N5 band gap provides a potential application scenario for the development of novel photocatalytic materials.

Facile fabrication of multifunctional superhydrophilic composite membranes for efficient oil-in-water emulsion separation

Numerous superwetting separation membranes have been designed for the management of oily wastewater due to their highly efficient oil/water separation efficiency. However, the long-term stability of these developed membranes is still restricted by membrane fouling. In this study, we synthesized multifunctional superhydrophilic membranes with superior anti-adhesive and anti-biofouling properties through simple co-deposition of dopamine, polyethyleneimine and CoFe2O4 (CFO) photocatalyst on the porous PVDF substrates for sustainable management of oil-in-water emulsion. The resultant optimal composite membranes showed the superhydropilicity with an underwater oil contact angle of 162.4° and achieved ca. 99.51 % oil/water separation efficiency with a maximum permeability of 232.2 L·m−2·h−1 in the treatment of oil-in-water emulsions driven by gravity. Moreover, the outstanding antibacterial performance of composite membrane was demonstrated by a nearly 100 % antibacterial rate during the exposure in 120-min visible light irradiation. Based on the synergistic effect of superhydrophilicity and photocatalysis, the fabricated composite membranes experienced a stable gravity-driven oil/water separation (oil rejection: >99.46 %) even after a 50-cycle filtration. Such an impressive filtration performance of the polydopamine/PEI/CFO composite membranes highlights their promising potential for sustainable and efficient treatment of oily wastewater.

Wide-spectrum-responsive MoS2/WS2 decorated Al-MOF nanohybrid with dual S-scheme heterojunction in facilitating sonophotocatalytic tetracycline abatement and pharmaceutical effluent treatment

The work investigates the application of a MoS2/WS2 decorated Al-MOF nanocomposite for the degradation of tetracycline (TC) in water by sonophotocatalysis. The nanocomposite revealed a dual S-scheme heterojunction that has a broad-spectrum response, resulting in a better efficiency for the degradation of TC (97%). The synergy index during sonophotocatalysis was measured to be 2.79. Moreover, the nanocomposite was effectively used to actively regulate the concentration of TC (73.2%) and other pollutants in pharmaceutical wastewater. An extensive analysis was performed to examine the impact of various significant parameters, including pH, catalyst dosage, TC concentration, and others. Sonophotocatalysis outperforms both sonocatalysis and photocatalysis, exhibiting pseudo-first-order kinetics. The improved performance can be credited to the formation of a dual S-scheme heterojunction, which facilitates the efficient transfer and separation of charge carriers that are stimulated by visible light exposure. Furthermore, the nanocomposite exhibited exceptional stability and demonstrated significant potential for being reused. The results suggest that the MoS2/WS2 decorated Al-MOF nanocomposite shows promise as a feasible choice for efficient and eco-friendly water treatment processes.

Streamline-directed tunable deterministic lateral displacement chip: A numerical approach to efficient particle separation

In conventional Deterministic Lateral Displacement (DLD), the migration behavior of a particle of specific size is determined by the critical diameter (Dc), which is predefined by the device's geometry. In contrast to the typical approach that alters the angle between the pillar array and fluid streamlines by modifying the geometrical parameters, this study introduces a novel perspective that focuses on changing the direction of the streamlines. The proposed technique offers a tunable DLD chip featuring a straightforward design that allows for easy fabrication. This chip features one completely horizontal pillar array with two bypass channels on the top and bottom of the DLD chamber. The width of these bypass channels changes linearly from their inlet to their outlet. Two design configurations are suggested for this chip, characterized by either parallel or unparallel slopes of the bypass channels. This chip is capable of generating a wide range of Dc values by manipulating two distinct control parameters. The first control parameter involves adjusting the flow rates in the two bypass channels. The second control parameter entails controlling the slopes of these bypass channels. Both of these parameters influence the direction of particle-carrying streamlines resulting in a change in the path-line of the particles. By changing the angle of streamlines with pillar array, the Dc can be tuned. Prior to determining the Dc for each case, an initial estimation was made using a Python script that utilized the streamline coordinates. Subsequently, through FEM modeling of the particle trajectories, precise Dc values were ascertained and compared with the estimated values, revealing minimal disparities. By adjusting the flow rate and slope of the bypass channels, maximum Dc ranges of 4–10 μm and 8–13 μm can be achieved, respectively. This innovative chip enables the attainment of Dc values spanning from 0.5 to 14 μm.

Nickel-cobalt hydrogen phosphate membrane with outstanding anti-crude oil-fouling capability and its microscopic anti-fouling mechanism

Oil/water separation membranes with superior anti-fouling properties against highly viscous oils are crucial for the efficient treatment of oily wastewater. Herein, the effects of functional groups in an inorganic superhydrophilic membrane on the anti-fouling properties of the membrane are investigated. Using a facile one-step electrochemical deposition method, Ni1-xCoxHPO4·3H2O membranes were formed on a Cu(OH)2 microneedle-coated copper mesh (CCNC–P) with superhydrophilic and underwater superoleophobic properties. All CCNC–P membranes with different Co2+ contents showed outstanding anti-fouling capability for oily wastewater such as those containing crude oil. The CCNC–P(x = 0.5) membrane exhibited high separation efficiency reaching 99.7 % across five oil–water mixtures and oil-in-water emulsions, concurrently presenting an ultrahigh flux of 61695 L m−2 h−1 for crude oil–water mixture. Moreover, the membrane consistently maintained its separation performance during the long-term crude oil–water separation process. The flux decline ratio was below 1 %, and the flux recovery ratio approached 99.4 %. The CCNC–P membranes possessed superior chemical, thermal, and mechanical stability, suggesting significant potential for the industrial treatment of oily wastewater. Density functional theory calculation revealed that the HPO42− group in CCNC–P can strongly adsorb water molecules. The resultant stabilized hydration layer impeded the contact between the membrane surface and oil droplets, while the metal ions scarcely influenced the adsorption of water molecules on CCNC–P. These findings provide new insights into the development of novel oil–water separation membranes with higher anti-fouling capabilities against high-viscosity oils.

A simple and efficient method for separation of 99mTc from 100Mo targets

99mTc is regarded as the most important medical isotope, and its supply issues have garnered significant attention. A simple and efficient separation method was performed for the production of 99mTc from 100Mo target in this study. The entire process involves accelerator irradiation, 99mTc/100Mo separation, and target material recovery. The key aspect is separation process, which including the high-temperature conversion of metal molybdenum targets and the selective solution of 99mTc with normal saline. This method can separate highly pure 99mTc within 1.5 h, with a separation efficiency exceeding 80%. The reagents used in the separation process are minimal, resulting in less radioactive waste. Additionally, the target material is easy to reclaim, with a recovery rate of over 95%.

Rapid room temperature synthesis of CuBi2O4 via ball-milling strategy boost light-driven persistent activation of hydrogen peroxide

Photo-Fenton technology with the superiorities of photocatalysis and traditional Fenton catalysis can improve the catalytic efficiency of photocatalytic materials and thus achieve efficient degradation for organic pollutants. However, exploring a low-cost catalyst with excellent catalytic performance using a simple method remains a challenge. In this work, CuBi2O4 photocatalyst synthesized by a mechanical ball-milling strategy (M-CuBi2O4) was exploited and used for tetracycline (TC) degradation. The impact of solution pH and H2O2 dosage on the photo-Fenton degradation efficiency of M-CuBi2O4 towards TC was investigated. M-CuBi2O4 exhibited significant 85.1% of photo-Fenton catalytic activity for TC removal, which was 9.35 times higher than that of CuBi2O4 synthesized by hydrothermal method (H-CuBi2O4). The enhanced catalytic performance of M-CuBi2O4 was due to the superior charge carrier separation efficiency, wider photo-response range and increased generation of active species. The primary active substances involved in the photo-Fenton reaction for TC degradation were determined to be hydroxyl radicals (•OH), superoxide radicals (•O2-), and singlet oxygen (1O2). This study provides a streamlined and rapid approach for macro preparation of high-performance photocatalysts for dealing with antibiotic-contaminated wastewater.

Enhanced Photocatalytic Hydrogen Evolution Activity Driven by the Synergy Between Surface Vacancies and Cocatalysts: Surface Reaction Matters.

The incorporation of defects and cocatalysts is known to be effective in improving photocatalytic activity, yet their coupled contribution to the photocatalytic hydrogen evolution process has not been well-explored. In this study, We demonstrate that the incorporation of S vacancies and NiSe can contribute to the improvement of charge separation efficiency via the formation of a strong electric field within the bulk ZnIn2S4 (ZIS) and on its surface. More importantly, We also demonstrate that the synergy of S vacancies and NiSe benefits the overall hydrogen evolution activity by facilitating the H2O adsorption and dissociation process. This is particularly important for hydrogen evolution taking place under alkaline conditions where the proton concentration is low, allowing ZISv-NiSe (containing abundant S vacancies) to outperform ZIS-NiSe under alkaline conditions. In contrast, under acid conditions, since there are already sufficient amounts of protons available for reaction, the hydrogen evolution activity became governed by the hydrogen adsorption/desorption process rather than the H2O dissociation process. This leads to ZIS-NiSe exhibiting higher activity than ZISv-NiSe due to its more favorable hydrogen adsorption energy. The findings thus provide insights into how defect and cocatalyst modification strategies can be tailor-made to improve hydrogen evolution activity under different pH conditions.

Delamination and Evaluation of Multilayer PE/Al/PET Packaging Waste Separated Using a Hydrophobic Deep Eutectic Solvent.

This research concerns the development and implementation of ground-breaking strategies for improving the sorting, separation, and recycling of common flexible laminate packaging materials. Such packaging laminates incorporate different functional materials in order to achieve the desired mechanical performance and barrier properties. Common components include poly(ethylene) (PE), poly(propylene) (PP), and poly(ethylene terephthalate) (PET), as well as valuable barrier materials such as poly(vinyl alcohol) (PVOH) and aluminium (Al) foils. Although widely used for the protection and preservation of food produce, such packaging materials present significant challenges for established recycling infrastructure and, therefore, to our future ambitions for a circular economy. Experience from the field of ionic liquids (ILs) and deep eutectic solvents (DESs) has been leveraged to develop novel green solvent systems that delaminate multilayer packaging materials to facilitate the separation and recovery of high-purity commodity plastics and aluminium. This research focuses on the development of a hydrophobic DES and the application of a Design of Experiments (DoE) methodology to investigate the effects of process parameters on the delamination of PE/Al/PET laminate packaging films. Key variables including temperature, time, loading, flake size, and perforations were assessed at laboratory scale using a 1 L filter reactor vessel. The results demonstrate that efficient separation of PE, Al, and PET can be achieved with high yields for material and solvent recovery. Recovered plastic films were subsequently characterised via Fourier-transform infra-red (FTIR) spectroscopy, Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) to qualify the quality of plastics for reuse.