Cadmium-contaminated wastewater from rapidly expanding industrial activities has become a pressing environmental challenge. Here, we developed a one-step mechanochemical modification strategy to enhance Cd(Ⅱ) removal by reconstructing endogenous Si–O and –OH networks in rice straw-derived biochar. By coupling alkaline treatment activation with mechanical ball milling, inherent silicates in the straw were effectively activated to form SiVO–Si and Si–O–C anchoring sites, while mechanical shear fractured polysaccharide chains and promoted the enrichment of surface –OH groups. The optimized adsorbent (Al-bmST1) exhibited a bifunctional adsorption interface with improved coordination affinity toward Cd(Ⅱ), achieving a removal efficiency of 88.01% and the adsorption capacity reached 27.1 mg/g. This performance was significantly superior to that of both the two-step modified biochar (Al-bmST2) and the biochar prepared solely via mechanical milling (bmST). In situ Fourier-transform infrared (FTIR) analysis and density functional theory (DFT) calculations confirmed that Cd(Ⅱ) formed stable ≡Si–O–Cd+ complexes, while surface –OH groups further strengthened adsorption stability. Life cycle assessment (LCA) further showed that the one-step mechanical chemical treatment reduced carbon emissions by 56.72% relative to the conventional straw pyrolysis process, without generating significant harmful gas emissions. These findings provide a low-carbon and efficient route for converting agricultural waste into functional adsorbents for heavy metal wastewater treatment.
A mesoporous SBA-15-anchored phosphine-gold(i) complex [SBA-15-Ph2P-AuCl] was prepared via immobilization of 3-(diphenylphosphino)propyltriethoxysilane onto SBA-15, followed by reaction with Me2SAuCl. With the use of 5 mol% SBA-15-Ph2P-AuCl as a catalyst and 5 mol% AgPF6 as a cocatalyst, the hydrophosphoryloxylation reaction of alkynes with diphenyl phosphate proceeded smoothly in toluene under mild conditions to deliver a wide array of kinetic enol phosphates in good to excellent yields with wide tolerance of functional groups. Besides, the regio- and stereoselective hydrophosphoryloxylation of 1-haloalkynes with diphenyl phosphate also proceeded effectively in the presence of 5 mol% SBA-15-Ph2P-AuCl/AgOTf in toluene at 50 degrees C, affording (Z)-alkenyl halophosphates in high yields. This new heterogenized phosphine-gold(i) catalyst could be conveniently recovered by centrifugation of the reaction mixture and recycled several times without a significant loss of catalytic activity.
Hierarchically porous silica ceramics were prepared by gel casting using the pore structures of fly ash hollow spheres (FAHSs), diatomite and expanded perlite as non-sacrificial templates. The effects of the amount of dispersant and binder (sol), FAHS particle size, slurry composition and sintering temperature on the structure and properties of porous ceramics were investigated. Results showed that the structural inhomogeneity of porous ceramics could be avoided by using sodium carboxymethyl cellulose as dispersant. Using silica sol as binder and FAHSs, diatomite and perlite powder as main raw materials, the porous ceramics prepared at 1200 degrees C not only have obvious hierarchical pore structures, but also have low diameter shrinkage (1.99%), high compressive strength (18.54 MPa) and excellent thermal insulation. This paper provides a method to prepare hierarchical porous ceramics using porous inorganic powders as raw material and pore-forming agent, and addresses the resource utilization of porous powders represented by FAHSs.
High-entropy nanoparticles combine the intrinsic properties of high-entropy materials with nanoscale effects to enhance electrocatalytic activity. This study employs a defect engineering strategy, utilizing the interfacial-mediating role of oxygen vacancy-enriched CeO2 carriers to successfully construct a series of high-entropy oxide (HEO) nanoparticles (NPs), Cu0.1Co0.1Nd0.1M0.1Ce0.6O2 (M = Ni, Zr, Fe, Mn, Al). A surface single-phase reconstruction in nickel-based high-entropy oxide nanoparticles was confirmed through high-resolution transmission electron microscopy, while Raman spectroscopy revealed oxygen defect-mediated regulation of interfacial electronic structures, synergistically enabling uniform multi-metallic component dispersion. Comparative analysis of electrochemical activity demonstrates that Cu0.1Co0.1Nd0.1Ni0.1Ce0.6O2 provides the most significant enhancement to the surface activity of CeO2. This strategy offers an effective pathway for designing defect-mediated high-efficiency electrocatalysts.
Hydrogen storage materials are crucial for advancing the utilization of hydrogen energy. In this work, we conduct first-principles investigations on trigonal LiMgXH6 (X = Al, Ga, In) hydrides to evaluate their potential as promising materials for hydrogen storage and optoelectronic applications. The structural stability of LiMgAlH6 is established through a comprehensive assessment of its phonon spectrum, formation enthalpy, and elastic constants. Both LiMgGaH6 and LiMgInH6 are dynamically and mechanically stable, but their thermodynamic instability is evident from the positive formation enthalpies. Analysis of the mechanical properties reveals that these complex hydrides are brittle in nature. Electronic structure calculations suggest that all hydrides are indirect bandgap materials. Among them, LiMgAlH6 (4.45 eV) is an insulator, while LiMgGaH6 and LiMgInH6, with band gaps of 2.78 eV and 3.10 eV, are semiconductors. These hydrides are strong ultraviolet absorbers, with an absorption coefficient greater than 106 cm-1. For hydrogen storage, the gravimetric capacities are 9.41 wt% for LiMgAlH6, 5.65 wt% for LiMgGaH6, and 3.98 wt% for LiMgInH6. Meanwhile, they exhibit volumetric capacities exceeding 100 g & sdot;H2/L. According to our present study, LiMgAlH6 shows the greatest promise for hydrogen storage, which is attributed to its excellent stability, high gravimetric, and large volumetric capacities.
