A core-shell structured Zn/La magnetic mesoporous silica (denoted as Zn/La-MMS) composite we successfully constructed via etching and co-deposition techniques, achieving exceptionally efficient adsorption of phosphate. At an optimized Zn/La ratio of 0.5 (i.e., Zn/La-0.5 MMS), the composite exhibited an ordered mesoporous structure and superior adsorption performance with a maximum phosphate adsorption capacity of 140.9 mg P/g (15-fold higher than the pristine MMS). High adsorption performance was achieved across a broad pH range of 3 to 11 and in the presence of substantial amounts of co-existing ions/substances (Cl⁻, NO₃⁻, SO₄²⁻, HCO₃⁻, and humic acid at concentrations 20–50 times that of the PO₄³⁻-P concentration). After five adsorption-regeneration cycles, 79 % adsorption capacity remained with material recovery rates >95 % via magnetic separation. A bimetallic synergistic mechanism was revealed via X-ray absorption fine-structure characterizations and density functional theory (DFT) calculations. The electronegativity difference between La and Zn induces interfacial electron redistribution, driving electron back-donation from the La/Zn-O hybridized orbitals to the O 2p antibonding orbitals of HPO₄²⁻, forming stable covalent coordination bonds (La-O-P/Zn-O-P), which allowed the exceptionally high and efficient adsorption of phosphate. This phenomenon is expected to have important implications for the development of novel adsorption materials for advanced removal of phosphate.

Thermochemical heat-storage applications, based on the reversible endo-/exothermic hydration reaction of salts, are intensively investigated to search for compact heat-storage devices. To achieve a truly valuable storage system, progressively complex salts are investigated. For these salts, the equilibrium temperature and pressure conditions are not always easy to predict. However, these conditions are crucial for the design of thermochemical heat-storage systems. A biased grand-canonical Monte Carlo (GCMC) tool is developed, enabling the study of equilibrium conditions at the molecular level. The GCMC algorithm is combined with reactive force field molecular dynamics (ReaxFF), which allows bond formation within the simulation. The Weeks-Chandler-Andersen (WCA) potential is used to scan multiple trial positions for the GCMC algorithm at a small cost. The most promising trial positions can be selected for recomputation with the more expensive ReaxFF. The developed WCA-ReaxFF-GCMC tool was used to study the hydration of MgCl2·nH2O. The simulation results show a good agreement with experimental and thermodynamic equilibriums for multiple hydration levels. The hydration shows that water, present at the surface of crystalline salt, deforms the surface layers and promotes further hydration of these deformed layers. Additionally, the WCA-ReaxFF-GCMC algorithm can be used to study other, non-TCM-related, reactive sorption processes.