Kraft Pulp Research Articles

Silver-Doped Titanium Oxide Layers for Improved Photocatalytic Activity and Antibacterial Properties of Titanium Implants.

Titanium has a long history of clinical use, but the naturally forming oxide is not ideal for bacterial resistance. Anodization processes can modify the crystallinity, surface topography, and surface chemistry of titanium oxides. Anatase, rutile, and mixed phase oxides are known to exhibit photocatalytic activity (PCA)-driven bacterial resistance under UVA irradiation. Silver additions are reported to enhance PCA and reduce bacterial attachment. This study investigated the effects of silver-doping additions to three established anodization processes. Silver doping showed no significant influence on oxide crystallinity, surface topography, or surface wettability. Oxides from a sulfuric acid anodization process exhibited significantly enhanced PCA after silver doping, but silver-doped oxides produced from phosphoric-acid-containing electrolytes did not. Staphylococcus aureus attachment was also assessed under dark and UVA-irradiated conditions on each oxide. Each oxide exhibited a photocatalytic antimicrobial effect as indicated by significantly decreased bacterial attachment under UVA irradiation compared to dark conditions. However, only the phosphorus-doped mixed anatase and rutile phase oxide exhibited an additional significant reduction in bacteria attachment under UVA irradiation as a result of silver doping. The antimicrobial success of this oxide was attributed to the combination of the mixed phase oxide and higher silver-doping uptake levels.

1-Ethyl-3-methylimidazolium Acetate as a Reactive Solvent for Elemental Sulfur and Poly(sulfur nitride).

We investigate the reactive dissolution process of poly(sulfur nitride) (SN)x in the ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate [EMIm][OAc] in comparison to the process of elemental sulfur in the same IL. It has been known from the literature that during the reaction of S8 with [EMIm][OAc], the respective thione is formed via a radical mechanism. Here, we present new results on the kinetics of the formation of the respective imidazole thione (EMImS) via the hexasulfur dianion [S6]2- and the trisulfur radical anion [S3]•-. We can show that [S6]2- is formed first, which dissociates then to [S3]•-. Also, long-term stable radicals occur, which are necessary side products provided in a reaction scheme. During the reaction of [EMIm][OAc] with (SN)x chains, two further products can be identified, one of which is the corresponding imine. The reactions are followed by time-resolved NMR spectroscopic methods that showed the corresponding product distributions and allowed the assignment of the individual signals. In addition, continuous-wave (CW) EPR and UV/vis spectroscopic measurements show the course of the reactions. Another significant difference in both reactions is the formation of a long-term stable radical in the sulfur-IL system, which remains active over 35 days, while for the (SN)x-IL system, we can determine a radical species only with the spin trap 5,5-dimethyl-1-pyrrolin-N-oxide, which indicates the existence of short-living radicals. Since the molecular dynamics are restricted based on the EPR spectra, these radicals must be large.

Process Design for Direct Production of Battery Grade Nickel Sulfate

The clean energy transition has increased the global demand of nickel sulfate used in the Li-ion batteries. A short-term solution is to refine the nickel sulfate product from nickel intermediates. In the long-term, new direct nickel sulfate production technologies are needed. This research focused on the modeling-based concept development of a novel direct hydrometallurgical nickel sulfate process consisting of chemical leaching, impurity removal by precipitation, solvent extraction, and crystallization as an alternative to the conventional nickel sulfate production route via a nickel matte intermediate. The conventional process route with the studied nickel concentrate had lower chemical consumption and waste production compared to direct hydrometallurgical process where approximately 60% of iron was leached consuming oxygen, and the following iron precipitation step consuming calcium carbonate resulted in a high amount of iron precipitate together with gypsum. However, hydrometallurgical alternatives are often suitable for lower ore grades or volumes and can recover copper as by-product metal. The biggest impacts on carbon footprint from chemical consumption in the direct hydrometallurgical process were generated in iron precipitation and oxygen use in leaching. With the studied nickel concentrate, pyrrhotite played a key role in both oxygen use and iron precipitation. In the leaching step, 68% of total oxygen consumption was related to pyrrhotite leaching, while in iron removal 73% of total iron originated from pyrrhotite. Thus, especially pyrrhotite removal prior to leaching needs to be developed to reduce the carbon dioxide footprint, when the pyrrhotite content in the material is high.Graphical

Rational Design of Phase-Engineered WS2/WSe2 Heterostructures by Low-Temperature Plasma-Assisted Sulfurization and Selenization toward Enhanced HER Performance.

Efficient hydrogen generation from water splitting underpins chemistry to realize hydrogen economy. The electrocatalytic activity can be effectively modified by two-dimensional (2D) heterostructures, which offer great flexibility. Furthermore, they are useful in enhancing the exposure of the active sites for the hydrogen evolution reaction. Although the 1T-metallic phase of the transition metal dichalcogenides (TMDs) is important for the hydrogen evolution reaction (HER) catalyst, its practical application has not yet been much utilized because of the lack of stability of the 1T phase. Here, we introduce a novel approach to create a 1T-WS2/1T-WSe2 heterostructure using a low-temperature plasma-assisted chemical vapor reaction (PACVR), namely plasma-assisted sulfurization and plasma-assisted selenization processes. This heterostructure exhibits superior electrocatalytic performance due to the presence of the metallic 1T phase and the beneficial synergistic effect at the interface, which is attributed to the transfer of electrons from the underlying WS2 layer to the overlying WSe2 layer. The WS2/WSe2 heterostructure catalyst demonstrates remarkable performance in the HER as evidenced by its small Tafel slope of 57 mV dec-1 and exceptional durability. The usage of plasma helps in replacing the top S atoms with Se atoms, and this ion bombardment also increases the roughness of the thin film, thus adding another factor to enhance the HER performance. This plasma-synthesized low-temperature metallic-phase heterostructure brings out a novel method for the discovery of other catalysts.

Refinability of mercerized softwood kraft pulp

In this study, the impact of mercerization and PFI refining on the properties of softwood kraft pulp was investigated. Never-dried softwood kraft pulp was treated with 15 wt% NaOH to generate highly hydrated fibers, followed by PFI refining to increase pulp fibrillation and porosity. The original and modified pulp properties were assessed for morphological and chemical composition. Differential scanning calorimetry (DSC) tests and water retention value (WRV) measurements were conducted to evaluate pulp swelling behavior and porosity. Fiber bonding potential and strength properties were evaluated from handsheets of mercerized and unmercerized pulp. Mercerization with 15 wt% NaOH successfully converted cellulose I to cellulose II, leading to slightly increased pulp swelling and micropore volume. However, the mercerization reduced handsheet strength properties. Furthermore, PFI refining resulted in a negligible enhancement of bonding in mercerized pulp, in stark contrast to its significant effect on unmercerized kraft pulp.

Mirror Plane Effect of Magnetoplumbite-Type Oxide Restraining Long-Chain Polysulfides Disproportionation for High Loading Lithium Sulfur Batteries.

A facile solid-state approach is employed to synthesize a novel magnetoplumbite-type oxide of NdMgAl11O19, which integrates spinel-stacking layers (MgAl2O4) with Nd-O6 mirror plane structures. The resulting NdMgAl11O19 exhibits remarkable catalytic activity and conversion efficiency during the sulfur reduction reaction (SRR) in lithium-sulfur batteries. By employing the 2D projection mapping technique of in situ confocal Raman spectroscopy and electrochemical technique, it is discovered that the exposed mirror plane structure of Nd-O6 can effectively suppress the undesiring disproportionation reaction (S8 2-→S6 2-+1/4 S8) of long-chain lithium polysulfides at the initial stages of sulfur reduction, thereby promoting the positive process of sulfur to lithium sulfide. This not only mitigates the issue of sulfur shuttle loss but also significantly improve the kinetics of the conversion process. Leveraging these advantages, the NdMgAl11O19/S cathode delivered an impressive initial capacity of up to 1398 mAh g-1 at an electrolyte/sulfur (E/S) ratio of 5.1µL mg-1 and a sulfur loading of 2.3mg cm-2. Even when the sulfur loading is increased to 10.02mg cm-2, the cathode retained a reversible areal capacity of 10.01 mAh cm-2 after 200 cycles. This mirror engineering strategy provides valuable and universal insights into enhancing the efficiency of cathodes in Li-S battery.

Influence of Soda and Kraft lignin in polyurethane coatings for the corrosion protection of mild steel in 3.5 % NaCl solution

This study highlights the potential of coconut shell biomass waste-derived lignins (CSL) as corrosion inhibitors to reinforce the coating properties of polyurethane. The utilization of CSL involves a green approach to prepare eco-friendly metallic coatings. Herein, lignin was extracted via Kraft and Soda pulping processes. The present findings indicated that the percentage yield of Soda lignin (SL) (26.43 ± 0.75 %) was significantly higher than that of Kraft lignin (KL) (8.52 ± 0.39 %). Electrochemical impedance spectroscopy and potentiodynamic polarization corrosion monitoring techniques were used to evaluate the anticorrosive performance of modified polyurethane coatings on mild steel exposed to 3.5 % NaCl solution. In this study, doping concentration of 5 wt% KL and SL into polyurethane attained the optimum anticorrosion performance. The surface conditions of uncoated and coated mild steel substrates were investigated through scanning electron microscopy/energy dispersive X-ray (EDX) analysis, salt spray and adhesion tests. EDX analysis demonstrated that polyurethane added with 5 wt% doping concentration of SL contained the highest content of Fe (86.05 wt%) compared to 5 wt% KL which contained 79.64 wt% of Fe, whereas neat polyurethane coating contained 75.43 wt% of Fe. Hence, enhanced corrosion protection of polyurethane through the addition of CSL, particularly SL, possesses a viable and an effective green approach to utilize coconut shell biomass waste for the application as a potential corrosion inhibitor in organic coatings.

Effects of optically inert ions on up-conversion luminescence and temperature-sensing properties of Y2O2S: Er3+/Yb3+/Tm3+ phosphors

The quenching of luminescence in Er3+/Yb3+ co-doped with Tm3+ presents a dilemma as it substantially diminishes thermometric performance. In this study, Y2O2S: Er3+/Yb3+/Tm3+ phosphors were synthesized using a homogeneous precipitation method combined with a sulfurization process. In addition, three sets of fluorescence intensity ratio (FIR) models were designed, which have self-calibration function. The effects of incorporation of Li+ or Li+/Ba2+ on the up-conversion luminescence (UCL) intensity and thermometric performance of the phosphors were systematically studied. The results show that the introduction of Li+ or Li+/Ba2+ co-doping leads to lattice distortion and the formation of oxygen ion vacancies in the lattice, which further accelerates the energy transfer process and mixes the charge transfer states, and ultimately dramatically improves the UCL and thermometric performance. The introduction of Li+ and Li+/Ba2+ co-doping enhanced the UCL of the materials by about 3.7 times and 5.6 times compared to Y2O2S: Er3+/Yb3+/Tm3+. When based on nonthermally coupled levels (NTCLs), the Sr-max of Li+/Ba2+ co-doped sample is 0.080 K−1 at 573 K, which is 87 % higher than that based on TCLs. These findings not only provide a new avenue for improving the UCL and thermometric performance but also provide an accurate self-calibration FIR model over a wide temperature range.

Recovery of rare earth elements from sedimentary rare earth ore via sulfuric acid roasting and water leaching

Rare earth elements were extracted using a sulfuric acid roasting-water leaching process. The effect of acid roasting on a new type of low-grade sedimentary rare earth ore found in Guizhou Province, China was analyzed using X-ray diffraction and scanning electron microscopy. A systematic study was conducted on process parameters such as amount of acid, roasting temperature, roasting time, water leaching temperature, and leaching time. The results reveal that the total recovery of rare earth elements reaches 81.37%, which is 3.1 times higher than that achieved through direct acid leaching, under the optimal conditions. In addition, the leaching rate of heavy rare earth elements reaches 72.53%. Rare earth elements and some other valuable metals are transformed into soluble sulfate through the local decomposition of clay minerals under the action of the sulfuric acid attack. The dissolution rates of aluminum, iron, and titanium ions are 34.94%, 17.05%, and 62.77%, respectively. The precipitation rate of Ti reaches 99%, and the loss of rare earth ions in the solution is less than 1%. Meanwhile, the results of a leaching kinetics analysis indicate that the leaching process of rare ions is controlled by diffusion. Precious metal ions such as iron and aluminum in the leaching solution can reduce the adsorption of rare earth ions by kaolinite. This study efficiently recovered rare earth ions under conditions of low calcination temperature and direct water leaching, resulting in reduced energy consumption of the extraction process and acidity of the leaching solution. These findings provide a solid foundation for the further separation and extraction of rare earth ions.

ELECTROCHEMICAL REDUCTION OF ELEMENTAL SULFUR IN ETHYLENE GLYCOL ELECTROLYTE

The work is devoted to the study of the mechanism of reduction of elemental sulfur from ethylene glycol. For this purpose, linear and cyclic voltampere polarization curves were recorded. The influence of sulfur concentration in ethylene glycol electrolyte, potential unfolding rate and temperature on the sulfur reduction process was investigated. By recording the cyclic polarization curve, the range of potentials at which the reduction of elemental sulfur and its anodic oxidation occur was determined. It has been established that an increase in the concentration of sulfur in the electrolyte and temperature raises the speed of its reduction, and the process itself is controlled by the diffusion of sulfur ions to the cathode surface. In addition, the polarization curves on the platinum rotating disc electrode were recorded. The obtained data, namely the rectilinear dependence of ip on the rotation speed of the electrode (ω) to the power of 0.5, confirm the proposal that the process of reduction of elemental sulfur is accompanied by diffusion polarization. The dependence of the current density on the rotation speed of the electrode to the power of 0.5 at different potentials showed that the process of reduction of elemental sulfur in non-aqueous ethylene glycol at potentials of (0.25÷0.4 V) is accompanied by diffusion polarization, whereas at potentials above 0.4 V, it is accompanied by electrochemical polarization. Keywords : Sulfur ions, electroreduction, polarization, scanrate.

In situ reconstructed Fe-Ni3S2/VSB-5 composite based on molecular sieve (VSB-5) for efficient oxygen evolution reaction

The oxygen evolution reaction (OER) is a multi-electron reaction compared to the hydrogen evolution reaction (HER), which severely limits the efficiency of water electrolysis. Therefore, the exploration of highly active, cost-effective, and stable catalysts is significant for the development of water electrolysis. Herein, a composite catalyst Fe-Ni3S2/VSB-5 was successfully fabricated by sulfurization and concomitant in-situ reconstruction of VSB-5. Fe-Ni3S2/VSB-5 exhibits a unique composite morphology consisting of microprisms with the multi-step-like surface of VSB-5 and the brushwood-like morphology of Fe-Ni3S2. The sulfurization process leads to the in-situ reconstruction of VSB-5. The original hexagonal prismatic morphology of VSB-5 changes into the prisms with multi-stepped surfaces. The reconstructed VSB-5 exhibits the increased pore disorder and exposes a large number of stepped crystal planes, which is beneficial for the exposure of active sites and the contact between the catalyst and the electrolyte, while maintaining the superhydrophilicity of the original VSB-5. Thus, the composite catalyst Fe-Ni3S2/VSB-5 demonstrates outstanding OER performance in 1.0 M KOH, only requiring 193 and 256 mV overpotentials to achieve 10 and 100 mA cm−2, respectively. More importantly, Fe-Ni3S2/VSB-5 exhibits excellent stability at 100 mA cm−2 for at least 180 hours.

Structural changes and assembly mechanisms of microbial communities during rapid sedimentation of Yellow River sediments

Microbial communities are essential for the biogeochemical cycles in aquatic ecosystems. The effects of sediment depositional processes on the microbial community characteristics in the Yellow River have not been extensively studied at the in-situ macroscopic scale. Since the Yellow River diversion reservoir has the sedimentation pond, it can be used as a natural experimental area. This study investigated changes in microbial community structures, functions, and assembly mechanisms under sediment deposition by analysing 26 water and sediment samples. The results showed that during rapid sediment deposition, different community structures formed between the water body and the sediment (Analysis of similarities, P<0.01), and the variability between them increased with increasing water depth. Sediments are more closely associated with carbon, nitrogen, and sulfur cycling processes, while water is more closely associated with light reactions. Under changing sediment concentrations, the microbial community diversities, community compositions, and functions changed significantly. Actinobacteria and Cyanobacteria were the species responsible for the significant differences in the microbial communities in the water, with linear discriminant analysis scores of 4.478–4.724 and 4.427–5.007, respectively. Water temperature, NH4+-N, and electrical conductivity were the most critical factors that affected the microbial community structures. During the rapid deposition of sediments, microbial community assembly was dominated by stochastic process. This study may provide a reference for exploring the mechanism of microbial community changes in reservoirs under the dynamic hydrological conditions of the Yellow River.

Characterization of Hot-Melt Kneading Process of Sulfur and Porous Carbon for All-Solid-State Batteries

Characterization of Hot-Melt Kneading Process of Sulfur and Porous Carbon for All-Solid-State Batteries

Evaluating the reinforcing potential of enzymatic cellulose nanocrystals in polypropylene nanocomposite

Cellulose nanocrystals (CNCs) produced through enzymatic hydrolysis exhibit physicochemical properties that make them attractive as eco-friendly reinforcing agents in polymer composites. However, the extent of their efficacy within a polymeric matrix is yet to be fully established. This study investigated the reinforcing capabilities of enzymatic CNC (approximately 3 nm in diameter) isolated from bleached eucalyptus Kraft pulp (BEKP), focusing on its application in polypropylene (PP) nanocomposites produced by injection molding. The study compared the performance of this enzymatic CNC (1–5 % wt) with PP composites reinforced with micro-sized cellulose fibers (BEKP at 10–30 % wt, approximately 13 μm) and additionally with commercial CNC produced by sulfuric acid hydrolysis. Despite enzymatic CNC experiencing agglomeration during spray-drying, leading to an average diameter increase to 3 μm, it still significantly increased the crystallization and glass transition temperature of the PP matrix. However, this agglomeration likely hindered the improvement of the mechanical properties within the nanocomposites. The results also showed that enzymatic CNC provided higher thermal stability at lower reinforcement levels compared to BEKP, but this came with a reduction in stiffness, posing a significant consideration in composite design. The addition of a coupling agent greatly enhanced the dispersion of reinforcements and the interfacial adhesion within the matrix, contributing to the enhanced performance of the composite properties. Additionally, enzymatic CNC demonstrated potential for superior reinforcement efficacy compared to commercially available CNC produced by sulfuric acid hydrolysis. In conclusion, enzymatic CNC exhibited a promising role as nano-reinforcement for thermoplastic polymer nanocomposites, exhibiting higher thermal properties at lower reinforcing loads than traditional micro-sized fiber reinforcements. The absence of sulfur, coupled with its higher thermal stability and sustainable potential, positions enzymatic CNC as a particularly favorable choice for applications involving direct contact with food, cosmetics, pharmaceuticals, and biomedical materials.

Review Metode Deposisi Elektrokimia Cu2ZnSnS4 sebagai Lapisan Absorber Sel Surya Lapisan Tipis

Cu2ZnSnS4 is a low-cost and environmentally friendly thin layer solar cell absorber material. The electrochemical deposition method is intended to study because it enables producing films with high homogeneity based on solution precursors. This research review focuses on examining the CZTS electrochemical deposition method in order to identify the effect of the sulfurization process (sulfurization temperature and time) so that the best electrochemical deposition process can be identified for future work of high-efficiency CZTS thin layer solar cell fabrication based on solution precursor. The results show that the Cu2ZnSnS4 layer deposited through the electrochemical method has a 1.4-1.6 eV bandgap range. The etching process to post-annealing 0.1M KCN is crucial to effectively and selectively remove CuS, ZnS, and Cu6Sn5 secondary phases.

Two-step process for the fabrication of direct FLG\\MoS2 heterostructures

MoS2 has proven its efficacy in flexible electronics, transistor devices, and various biological and chemical applications. However, it is still challenging to achieve large-area MoS2 monolayers with desired material quality and electrical properties to fulfill the requirement for practical applications. Moreover, the main strategy for the preparation of a 2D heterostructure it is based on the sequential stacking of the layered materials using wet or dry transfer methods which introduces many defects. This paper presents an economically viable and straightforward two-step methodology to obtain MoS2 thin films, encompassing magnetron sputtering deposition of Mo and subsequent annealing in a sulfur-rich environment. This approach successfully yielded MoS2 thin films on Si\\SiO2 substrates. Additionally, heterostructures consisting of few layer graphene (FLG) and MoS2 were directly obtained using the same method. The utilization of grazing incidence X-ray diffraction verified the formation of the hexagonal MoS2 phase, a finding further confirmed by Raman spectroscopy. X-ray photoelectron spectroscopy (XPS) investigations revealed the successful sulfurization process, with surface-bound oxides forming only subsequent to air exposure. Comprehensive assessment involving X-ray reflectivity, atomic force microscopy and XPS collectively inferred the fabrication of thin films comprised of a small number of MoS2 layers covering the entire substrate. Electrical assessments exhibited an electrical hysteresis, demonstrating its potential for memristor applications. Overall, this study outlines a cost-effective fabrication method for producing nanoscale MoS2 thin films with excellent properties, avoiding the use of toxic gases such as H2S. These findings contribute to the potential development of cutting-edge applications.

Investigation of Mazidagi phosphate ore in wet flue gas desulphurization

The employment of Mazidagi phosphate ore for wet flue gas desulphurization was investigated. The ore was exposed to sulfation processes in a three-phase double-stirred reactor to determine the effects of certain parameters on SO2 absorption. The absorption rate significantly increased with inlet SO2 concentration, gas flow rate, stirring speeds, and solid concentration but not with temperature. The absorption rate increases as the mass transfer coefficients and interface area value increase with stirring speeds. These parameters have also a prominent impact on the absorption rate depending on the dissolution rate of CaCO3. Based on these, the most effective parameters on SO2 absorption are liquid-phase stirring speed and suspension concentration, and the process is diffusion-controlled in the liquid phase. In addition, optimum conditions were determined, and then the ore was exposed to sulfation processes via a semi-batch operation mode. A comparison between raw and sulfated ore was examined for the changes in physical structure and chemical composition. Although the ratios of fluorapatite and carbonate-fluorapatite remained nearly constant, the ratio of calcite decreased significantly. It was determined from these investigations that the calcite in the phosphate ore has been converted into the CaSO3∙½H2O compound. Consequently, both the calcite in the phosphate ore was utilized effectively for wet flue gas desulphurization, and a phosphate-rich industrial product was obtained.

Deep removal of arsenic from arsenic-bearing gypsum using a seed-induced crystal control technique and its mechanisms

Arsenic-bearing gypsum (ABG), a byproduct from the lime/ferric sulfate process in the waste acid treatment of the heavy non-ferrous industry, represents a substantial hazardous arsenic (As) waste issue in China. Due to the potential arsenic leakage, the disposal of ABG poses an urgent challenge to the surrounding environment. The elevated As content and the low-value-added recycling products are the primary hurdles hindering ABG recycling. In this study, precise control over the gypsum crystal and As species in Na2SO4-H2SO4 solutions under mild conditions facilitated the deep removal of As (with a leaching efficiency of 92.45 % and a final product As concentration of 80.32 ppm) and simultaneous preparation of high-strength α-bassanite (with a compressive strength of 35.38 MPa) from the pre-treated ABG. This process occurred during the recrystallization from dihydrate gypsum (CaSO4·2H2O, DH) to α-bassanite (α-CaSO4·0.5H2O, α-HH), involving DH dissolution followed by α-HH crystallization. The encapsulated As was fully released during the dissolution process, crucial for the efficient elimination of As impurities. H2SO4 dissolved the released As, transforming it into the protonated species (H3AsO4) with a distinct structure and a less negative binding energy (ΔEB) to SO42-. This transformation prevented the chemical incorporation of the released As during the α-HH crystallization process. Additionally, the morphology and size of α-HH were controlled by seeding in the mixed solutions. The formation of large short-columnar α-HH crystals with a low specific surface area significantly reduced the surface adsorption of As, further enhancing As leaching efficiency. Importantly, the large short-columnar α-HH was identified as high-strength gypsum with high added value. This study provided innovative guidance for efficiently removing impurities from gypsum and pioneered a cost-effective approach for the clean and high-value utilization of industrial gypsum residues.

Porous CuS@CuSe heterostructure cathode in capacitive deionization for exceptional copper ion electrosorption from wastewater

Water pollution is a pressing environmental concern in today’s world. Among the various pollutants found in aquatic environments, heavy metals, due to their high activity and wide range, are of particular concern. In the field of aqueous copper ion batteries, CuSe and CuS have been recognized as excellent copper storage materials. Selenium (Se) exhibits remarkable cyclic stability but limited reversible capacity, whereas sulfur (S) shows superior reversible capacity but inadequate cyclic stability. In this study, we synthesized a heterogeneous hollow core–shell structure known as CuS@CuSe. This structure was achieved by utilizing Cu2O as a template for layer-by-layer sulfuration and selenisation processes. The CuS@CuSe structure provides more electrically active sites and lowers the energy barrier for reactions. As a result, when used as cathode materials in capacitive deionization (CDI), CuS@CuSe demonstrates exceptional electroadsorption capacity (647.0 mg g−1), a high ion transport rate of 17.1 mg g−1 min−1, and superior cycling properties. The adsorption mechanism of CuS@CuSe was investigated through characterization techniques and density functional theory (DFT) calculations. These findings not only contribute to the understanding of the adsorption process but also provide valuable insights for the design and development of effective electrode materials capable of selectively capturing copper ions from wastewater.

Synergistic valorization of rice straw and red brick demolition in development performance of lightweight cement mortars

This work deals with upgrading the undesirable agro- and industrial wastes, such as rice straw (RS), red brick demolition (RBP), and polystyrene foam (PSF), for construction purposes, as an excellent strategy to protect the environment. In this respect, the RS and its pulp fibers are modified by PSF, followed by their incorporating individually or in hybrid with RBP, in cement mortar formulation. As a substitute for fine aggregates. Six rice straw pulps used in this study were prepared from alkali, neutral, acidic, and kraft pulping agents. The effective performance of this investigated route is assessed from the mechanical properties, density, moisture resistance (thickness swelling and water absorption), measurements of the resulting mortar composites, as well as how the investigated treatment effects on behavior of RS fibers. The finding results show that the modified RS fibers, especially those results from KOH–NH4OH and neutral RS-pulping reagents, in hybrid with red brick waste provide motors with better mechanical and water resistance properties. These treated fibers have a synergistic role for including the RBP in mortar formulation to 30 %. The produced mortar has compressive strength 6.2 MPa and flexural strength 4.4 MPa, which is convenient to apply as load-bearing wall. Moreover, they provide improvement in resistance to thickness swelling and water absorption after 24-h exposure to water. The reduction in thickness swelling and water resistance reached 36.7 and 52.8 %, respectively. From the TGA measurements and SEM, it is interesting to notice that the investigated route accepts the RS fibers thermal stability and hydrophobic surface character.