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W-Mo-V high-speed steel (HSS) is a high-alloy high-carbon steel with a high content of carbon, tungsten, chromium, molybdenum, and vanadium components. This type of high-speed steel has excellent red hardness, wear resistance, and corrosion resistance. In this study, the alloying element ratios were adjusted based on commercial HSS powders. The resulting chemical composition (wt.%) is C 1.9%, W 5.5%, Mo 5.0%, V 5.5%, Cr 4.5%, Si 0.7%, Mn 0.55%, Nb 0.5%, B 0.2%, N 0.06%, and the rest is Fe. This design is distinguished by the inclusion of a high content of molybdenum, vanadium, and trace boron in high-speed steel. When compared to traditional tungsten-based high-speed steel rolls, the addition of these three types of elements effectively improves the wear resistance and red hardness of high-speed steel, thereby increasing the service life of high-speed steel mill-roll covers. JMatPro (version 7.0) simulation software was used to create the composition of W-Mo-V HSS. The phase composition diagrams at various temperatures were examined, as well as the contents of distinct phases within the organization at various temperatures. The influence of austenite content on the martensitic transformation temperature at different temperatures was estimated. The heat treatment parameters for W-Mo-V HSS were optimized. By studying the phase equilibrium of W-Mo-V high-speed steel at different temperatures and drawing CCT diagrams, the starting temperature for the transformation of pearlite to austenite (A_c1 = 796.91 °C) and the ending temperature for the complete dissolution of secondary carbides into austenite (A_ccm = 819.49 °C) during heating was determined. The changes in carbide content and grain size of W-Mo-V high-speed steel at different tempering temperatures were calculated using JMatPro software. Combined with analysis of A_c1 and A_ccm temperature points, it was found that the optimal annealing temperatures were 817–827 °C, quenching temperatures were 1150–1160 °C, and tempering temperatures were 550–610 °C. The scanning electron microscopy (SEM) examination of the samples obtained with the aforementioned heat treatment parameters revealed that the martensitic substrate and vanadium carbide grains were finely and evenly scattered, consistent with the simulation results. This suggests that the simulation is a useful reference for guiding actual production. Full article

Cu₂O thin films were deposited on soda-lime glass substrates using RF magnetron sputtering under various process pressures, and their structural, morphological, compositional, and optical properties were investigated. X-ray diffraction (XRD) revealed that the films crystallized in the cubic Cu₂O phase, with the highest crystallinity observed at 5 mTorr, as evidenced by the sharp and intense (111) peak. Raman spectroscopy confirmed the predominance of Cu₂O vibrational modes across all samples, with improved phase purity and crystallinity at 5 mTorr and 10 mTorr. Field-emission scanning electron microscopy (FE-SEM) showed that the films deposited at 5 mTorr and 10 mTorr exhibited densely packed, well-defined grains, while those at 1 mTorr and 15 mTorr displayed irregular or poorly defined morphologies. X-ray photoelectron spectroscopy (XPS) confirmed the presence of Cu(I) without significant secondary phases, with slight surface oxidation observed at higher pressures. Optical characterization revealed that transmittance increased with pressure, reaching ~90% in the NIR range at 15 mTorr. The optical band gap (E_g) values increased from 2.34 eV at 1 mTorr to 2.43 eV at 15 mTorr with higher process pressure. Cu₂O films deposited at 5 mTorr and 10 mTorr exhibited an optimal balance between high transparency and band gap values. These findings highlight the critical role of process pressure in determining the properties of Cu₂O thin films and identify 5 mTorr as the optimal deposition condition for achieving high-quality films with superior structural and optical performance. Full article

This investigation reports on the efficacy of a photoelectrocatalysis (PEC) system enhanced by a nitrogen-doped TiO₂ nanocrystal-modified TiO₂ nanotube array (N-TiO₂ NCs/TNTAs) anode paired with a graphene oxide/activated carbon (GO/AC) photocathode for diclofenac removal from effluent. The FE-SEM and EDX analyses validated the elemental composition of the anode—27.56% C, 30.81% N, 6.03% O, and 26.49% Ti. The XRD results confirmed the anatase phase and nitrogen integration, essential for photocatalytic activity enhancement. Quantum chemical simulations provided a comprehensive understanding of the red-shifted absorption bands in N-TiO₂, and UV-vis DRS demonstrated a red-shift in absorption to the visible spectrum, indicating improved light utilization. The PEC configuration achieved a photocurrent density of 9.8 mA/dm², significantly higher than the unmodified and solely nitrogen-doped counterparts at 4.8 mA/dm² and 6.1 mA/dm², respectively. Notably, this system reduced diclofenac concentrations by 58% within 75 min, outperforming standard photocatalytic setups. These findings underscore the potential of N-TiO₂ NCs/TNTAs-AC-GO/PTFE composite material for advanced environmental photoelectrocatalytic applications. Full article

Niobium (Nb) and tantalum (Ta) are quoted as “strategic” or “critical” elements for contemporaneous society. The main sources of Nb and Ta are minerals of the pyrochlore supergroup (PSGM) and the columbite group (CGM) mined from different magmatic lithologies. Textures and chemical compositions of PSGM and CGM often provide key information about the origin of NbTa mineralization. Therefore, we decided to carry out a detailed study of the relations between the PSGM and CGM and their post-magmatic transformations, and the Madeira peralkaline pluton (Brazil) is an ideal object for such a study. Textures of the PSGM and CGM were studied using BSE imaging and SEM mapping, and their chemical compositions were determined using 325 electron microprobe analyses. Pyrochlore from the Madeira granite can be chemically characterized as Na, Ca-poor, U- and Pb-dominant, and Sn- and Zn-enriched; REE are enriched only during alteration. Two stages of alteration are present: (i) introduction of Fe + Mn, with the majority of them consumed by columbitization; (ii) introduction of Si and Fe, and in lesser amounts also Pb and U: Si, Pb, and U incorporated into pyrochlore, iron forming Fe-oxide halos around pyrochlore. During both stages, F and Na decreased. In the case of a (nearly) complete pyrochlore columbitization, U and Th were exsolved to form inclusions of a thorite/coffinite-like phase. In contrast to altered pyrochlores from other localities, pyrochlore from Madeira shows a relatively high occupancy of the A-site. Although Madeira melt was Na-, F-rich, contemporaneous crystallization of cryolite consumed both elements and pyrochlore was, from the beginning, relatively Na-, F-poor. Full article

The study began by pre-sintering Ga₂O₃ powder at 950 °C for 1 h, followed by the preparation of a mixture of Ga₂O₃ and 12 at% NiO powders to fabricate a source target material. An electron beam (e-beam) system was then used to deposit NiO-doped Ga₂O₃ thin films on Si substrates. X-ray diffraction (XRD) analyses revealed that the pre-sintered Ga₂O₃ at 950 °C exhibited β-phase characteristics, and the deposited NiO-doped Ga₂O₃ thin films exhibited an amorphous phase. After the deposition of the NiO-doped Ga₂O₃ thin films, they were divided into two portions. One portion underwent various analyses directly, while the other was annealed at 500 °C in air before being analyzed. Field-emission scanning electron microscopy (FESEM) was utilized to process the surface observation, and the cross-sectional observation was primarily used to measure the thickness of the NiO-doped Ga₂O₃ thin films. UV-Vis spectroscopy was used to calculate the bandgap by analyzing the transmission spectra, while the Agilent B1500A was employed to measure the I-V characteristics. Hall measurements were also performed to assess the mobility, carrier concentration, and resistivity of both NiO-doped Ga₂O₃ thin films. The first innovation is that the 500 °C-annealed NiO-doped Ga₂O₃ thin films exhibited a larger bandgap and better electrical conductivity. The manuscript provides an explanation for the observed increase in the bandgap. Another important innovation is that the 500 °C-annealed NiO-doped Ga₂O₃ thin films revealed a high-energy bandgap of 4.402 eV. The third innovation is that X-ray photoelectron spectroscopy (XPS) analyses of the Ga_2p3/2, Ga_2p1/2, Ga_3d, Ni_2p3/2, and O_1s peaks were conducted to further investigate the reasons behind the enhanced electrical conductivity of the 500 °C-annealed NiO-doped Ga₂O₃ thin films. Full article

To effectively utilize industrial lignin, a large amount of waste produced by the pulp and paper industry, this paper primarily explores its potential as a substitute for coal-based reducing agents in the reduction of iron oxides. The weight change, phase change, and activation energy change during the reduction of iron oxide by industrial lignin were characterized using detection methods such as TG-DTG-DSC, XRD, and SEM. The results show that the maximum weight loss rate of industrial lignin reducing iron oxide is (4.52%·min⁻¹) > Lu’an anthracite (2.01%·min⁻¹) > Shenmu bituminous coal (1.57%·min⁻¹). The activation energy variation range during the reduction of Fe₂O₃ by industrial lignin, calculated using the Flynn–Wall–Ozawa (FWO) method, is 241.91~463.51 kJ·mol⁻¹, and the activation energy first decreased, then increased, then decreased slightly with the increase of conversion fraction. There is a coupling effect in the reduction of Fe₂O₃ by industrial lignin. Full article

Due to their excellent mechanical properties and corrosion resistance, high-entropy alloys (HEAs) have the potential to be used as new engineering structures and functional materials. In this study, an FeCo_1.5CrNi_1.5Ti_0.5HEA coating was prepared on the surface of a 1Cr18Ni9Ti alloy by laser cladding technology. Phase structure and microstructure were characterized by XRD and using an SEM. The corrosion resistance was evaluated by an electrochemical workstation, and the polarization curves were obtained in simulated seawater and 3.5 wt.% NaCl and 5% HCl solutions. The corrosion morphology of the Fe-based HEA coating was further characterized using the SEM, super depth of field observation, and 3D topological images. The results showed that the Fe-based HEA coating had a single-phase FCC structure with a grain size of about 10.7 ± 0.25 μM. Electrochemical analysis results showed that the corrosion resistance of the current Fe-based HEA coating was poor in HCl solutions. However, it exhibited good corrosion properties in simulated seawater and 3.5 wt.% NaCl solutions. Further analysis of the corrosion morphology revealed that in simulated seawater and the 3.5 wt.% NaCl solution, the surface of the current Fe-based HEA coating exhibited a preferential corrosion tendency between dendrites, while in the 5% HCl solution, it exhibited more obvious pitting characteristics. The results indicate that the current Fe-based HEA coating exhibits good comprehensive performance, especially in an acidic Cl⁻ corrosion environment. These findings provide a reference for the application of laser cladding prepared Fe HEA coatings. Full article

We present a novel method for preparing bioactive and biomineralized calcium phosphate (mCP)-loaded biopolymer composite scaffolds with a porous structure. Two types of polymers were investigated as matrices: one natural, cellulose acetate (CA), and one synthetic, polycaprolactone (PCL). Biomineralized calcium phosphate particles were synthesized via wet chemical precipitation, followed by the addition of organic biominerals, such as magnesium gluconate and zinc gluconate, to enhance the bioactivity of the pure CP phase. We compared the morphological and chemical characteristics of the two types of composites and assessed the effect of biomineralization on the particle structure of pure CP. The precipitated CP primarily consisted of nanocrystalline apatite, and the addition of organic trace elements significantly influenced the morphology by reducing particle size. FE-SEM elemental mapping confirmed the successful incorporation of mCP particles into both CA and PCL polymer matrices. Short-term immersion tests revealed that the decomposition rate of both composites is slow, with moderate and gradual ionic dissolution observed via ICP-OES measurements. The weight loss of the PCL-based composite during immersion was minimal, decreasing by only 0.5%, while the CA-based composite initially exhibited a slight weight increase before gradually decreasing over time. Full article

A uniformly coating transition metal oxide solution (TS-M) was developed to simultaneously remove residual Li compounds (RLCs) and stabilize the surface of NCM811 material. XRD analysis revealed that the synthesized cathode samples (TS-M, where M = Ti, Ge, Sn) exhibited hexagonal α-NaFeO₂ structures without impurity phases. FE-SEM and EDX results confirmed the formation of a uniform metal oxide coating (TS-Ti, TS-Ge: and TS-Sn) on the surface of NCM811, demonstrating its potential as a high-performance cathode material for lithium-ion batteries (LIBs). Among the treated samples, the TS-Sn sample delivered an excellent discharge capacity of 172.4 mAh g⁻¹ with a retention of 90.4% after 50 cycles at a 1.0 C rate, outperforming the TS-Ge and TS-Ti samples. Electrochemical impedance spectroscopy (EIS) further validated the improved impedance of NCM samples after Ti, Ge, and Sn coatings. Based on these findings, the application of Ti, Ge, and Sn metal oxide coatings to NCM811 is considered a reliable surface modification strategy for enhancing electrochemical performance by eliminating RLCs and stabilizing the surface. Full article

The production of green hydrogen through proton exchange membrane water electrolysis (PEMWE) is a promising technology for industry decarbonization, outperforming alkaline water electrolysis (AWE). However, PEMWE requires significant investment, which can be mitigated through material and design advancements. Components like bipolar porous plates (BPPs) and porous transport films (PTFs) contribute substantially to costs and performance. BPPs necessitate properties like corrosion resistance, electrical conductivity, and mechanical integrity. Titanium, commonly used for BPPs, forms a passivating oxide layer, reducing efficiency. Effective coatings are crucial to address this issue, requiring conductivity and improved corrosion resistance. In this study, porous Ti64 structures were fabricated via powder technology, treating them with thermochemical nitriding. The resulting structures with controlled porosity exhibited enhanced corrosion resistance and electrical conductivity. Analysis through scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), grazing incidence XRD and X-ray photoelectron spectroscopy (XPS) confirmed the effectiveness of the coating, meeting performance requirements for BPPs. Full article

A composite Fe-MOF-C/N was prepared with Fe-MOF and g-C₃N₄ precursors, and its activation property of peroxymonosulfate (PMS) in the degradation of Sulfamethoxazole (SMX) was studied. XRD, SEM, and TEM analyses showed that Fe-MOF-C/N was porous and mainly composed of phases of Fe₃N, C_0.08Fe_1.92, and graphite. XPS indicated that Fe-MOF-C/N mainly had Fe, C, N, and O elements, among which Fe existed in the form of Fe²⁺ and Fe³⁺. Fe-MOF-C/N was used to activate PMS to degrade SMX, and the result showed that Fe-MOF-C/N had excellent catalytic performance and 84.17% of SMX could be removed in 8 min. Free radical quenching experiments showed that ¹O₂ was the main active species in Fe-MOF-C/N/PMS. The stability experiment showed that Fe-MOF-C/N had good stability, and the degradation rate of SMX only decreased by 5.8% after five times of use. Full article

This work presents a novel hydrothermally aided sol-gel method for preparation of mesoporous silica nanoparticles (MSNs) with a narrow particle size distribution and varied pore sizes. The method was carried out in alkaline media in presence of polyethylene glycol (PEG) and cetyltrimethylammonium chloride (CTAC) as dual templates and permitted the synthesis of spherical mesoporous silica with a high surface area (1011.42 m²/g). The MSN materials were characterized by FTIR, Thermogravimetric (TG), Nitrogen adsorption and desorption and Field emission scanning electron microscopic analysis (FESEM). The materials feasibility as solid phase adsorbent has been demonstrated using cationic dyes; Rhodamine B (RB) and methylene blue (MB) as models. Due to the large surface area and variable pore width, the adsorption behaviors toward cationic dyes showed outstanding removal efficiency and a rapid sorption rate. The adsorption isotherms of RB and MB were well-fitted to the Langmuir and Freundlich models, while the kinetic behaviours adhered closely to the pseudo-second-order pattern. The maximum adsorption capacities were determined to be 256 mg/g for MB and 110.3 mg/g for RB. The findings suggest that MSNs hold significant potential as solid-phase nanosorbents for the extraction and purification of dye pollutants, particularly in the analysis and treatment of effluents containing cationic dyes. Full article

This study investigates the application of chromizing and titanizing coatings on low-carbon steel (LCS) via the pack cementation process, utilizing various compositions, temperatures, and durations. The coating was analyzed using standard techniques, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and Vickers hardness testing, to determine their characteristics. The kinetics of the pack chromizing, titanizing, and chromotitanizing of low-carbon steel exhibited parabolic behavior, with the rate constant with increasing temperature. The formed diffusion layers primarily consisted of Cr, Ti, Cr_1.9Ti, FeTi, Al₂O₃, Cr₂O₃, TiO₂, and Cr_1.36Fe_0.52, in addition to Fe. The microhardness reached its highest value of 900 HV_0.01 Kg_f with 48% FeTi, followed by 790 HV_0.01 Kg_f with 12% FeCr–36% FeTi, 730 HV_0.01 Kg_f with 24% FeCr–24% FeTi, 680 HV_0.01 Kg_f with 36% FeCr–12% FeTi, and 560 HV_0.01 Kg_f with 48% FeCr. The results indicate a significant enhancement in the mechanical properties of low-carbon steel through the coating process. This study confirms that the pack cementation coatings of chromizing, titanizing, and chromotitanizing significantly enhance the surface hardness and mechanical integrity of low-carbon steel. The controlled diffusion process leads to the formation of robust intermetallic layers, and the variation in FeCr and FeTi composition allows for tailored mechanical properties. Additionally, the results suggest that the interplay between Cr and Ti promotes the development of a complex, multilayered microstructure that balances hardness with potential toughness, providing a broad spectrum of industrial applications. This research underscores the versatility of pack cementation as an effective method to engineer advanced coatings, offering a cost-efficient pathway to enhance the performance of low-carbon steel in demanding environments. Full article

Xuanwei and the neighboring Fuyuan (XF) counties in Yunnan Province have the highest lung cancer incidence rates in China. Previous studies suggest that the nano-minerals released during the combustion of locally sourced “smoky” (bituminous) coal are the primary contributors to these elevated cancer rates. The coal ash generated during combustion predominantly consists of nano-minerals, which can be resuspended into the atmosphere during routine ash-handling activities. In this study, coal ash samples from XF counties and four additional provinces with lower lung cancer incidence rates were resuspended to simulate ash-handling activities and subsequently collected using a cascade PM_2.5 sampler. Individual particles were analyzed using a high-resolution scanning electron microscope coupled with energy-dispersive X-ray spectroscopy (SEM-EDX). Based on their morphology and elemental composition, the particles were categorized into five major types: quartz, Si- and Al-rich (SiAl-rich), Ca-rich, Ca- and Mg-rich (CaMg-rich), and Fe-rich particles. The relative abundance of crystalline quartz particles was significantly higher in Xuanwei (22.2%) and Fuyuan (13.7%) compared to the other provinces, where quartz was also detected in lower concentrations. Similarly, the proportion of Fe-rich particles was notably higher in Xuanwei (10.9%) and Fuyuan (5.1%) than in other regions. These findings highlight the potential role of quartz and Fe-rich particles in contributing to the high lung cancer rates observed in XF counties. Further research is warranted to elucidate the toxicological mechanisms underlying the health effects of these particle types. Full article

This study reported a one-spot preparation of magnetic composite carbon (MCC@Fe) from microcrystalline cellulose (MC). The pure cellulose was impregnated in iron (III) chloride solution and carbonized at 650 °C. The MCC@Fe composite adsorbent underwent various characterization techniques. XRD identified nanostructured Fe₃O₄ particles with an average crystallite size of 34.3 nm embedded in the core subunits of the material. FESEM images indicated a rough and irregular surface, with some cavities along its surface, incorporating Fe₃O₄ nanoparticles, while EDS analysis confirmed the presence of elements like Fe, C, and O. Notably, combining thermal and chemical treatments produces a composite with more pores and a high specific surface area (500.0 m² g⁻¹) compared to MC (1.5 m²/g). VSM analysis confirmed the magnetic properties (0.76 emu/g), while the Hydrophobic Index (HI) showed that MCC@Fe was hydrophobic (HI 1.395). The adsorption studies consisted of kinetic, mass transfer, equilibrium, and thermodynamics studies. Kinetic study of the adsorption of paracetamol on MCC@Fe composite proved to be rapid, and the time necessary for covering 95% of the surface (t_0.95) was lower than 27 min following the fractal-like pseudo-first-order model (FPFO). Liu’s isotherm proved to be the most appropriate for understanding the adsorption equilibrium. Remarkably, the maximum sorption capacity (Q_max) of paracetamol was 34.78 mg g⁻¹ at 45 °C. The ΔH° value (+27.00 kJ/mol) and the negative ΔG° values were consistent with the physisorption mechanism and favorable process. Furthermore, the mass transfer mechanism showed that the transfer is governed by the intraparticle diffusion model, with surface diffusion being the rate-limiting step when considering the Biot number greater than 100. This research displayed a single-route production of inexpensive magnetic nano adsorbents capable of efficiently eliminating paracetamol from aqueous environments. Full article