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ZIF-8, a metal–organic framework that has significant benefits such as a substantial specific surface area, abundant active sites, and high porosity, has extensive application in environmental remediation. However, ZIF-8 is powdery and easily agglomerated, making it difficult to separate ZIF-8 from aqueous solutions and thus limiting its practical application in wastewater treatment. In this work, sodium alginate was chosen as a gel matrix, and CaCl2 as a cross-linking agent to form a calcium cross-linked MOF gel material (ZIF-8/SA). The batch adsorption investigations demonstrated that the saturated adsorption capacities of ZIF-8/SA in single Mn2+ pollution solution and Mn–Cu–Cd composite pollution solution are 179.86 mg g−1 and 101.86 mg g−1, respectively. Specifically, the adsorption of Mn2+ followed the Langmuir model and exhibited monomolecular layer adsorption. Furthermore, the adsorption of Cu2+ and Cd2+ followed the quasi-first-order kinetic model, which is primarily physical adsorption. The adsorption order of ZIF-8/SA for contaminants in the adsorption process is as follows: Cu2+ > Cd2+ > Mn2+. The SEM-EDS, FT-IR, and XPS studies revealed that the adsorption mechanism of ZIF-8/SA mostly involves ion exchange, coordination of carboxyl/hydroxyl/amino groups, and electrostatic attraction. To summarize, the experimental findings of this study demonstrate that the synthetic ZIF-8/SA hydrogel has promising applications for practical pollution treatment. [ABSTRACT FROM AUTHOR]

Na-ion batteries (SIBs) are emerging as a promising alternative to Li-ion batteries for large-scale energy storage in light of abundant Na resources and their low cost. Development of appropriate electrode materials that can conquer some critical issues such as low theoretical storage capacity and sluggish redox kinetics resulting from the larger radius of Na is urgently needed for their practical applications. In this work, boron-rich 2D BxN (x = 2, 3, and 5) has been explored as promising anode materials for high-performance SIBs based on density functional theory calculations. BxN electrodes exhibit moderate affinity toward Na-ions with adsorption energies of −0.41 to −1.21 eV, which allows stable Na-ion intercalation without the formation of metal dendrites. Moreover, both B3N and B5N deliver low diffusion barriers (0.28 and 0.08 eV) for Na-ion migration, guaranteeing a high charging/discharging rate. More importantly, these BxN anodes exhibit not only a remarkably high theoretical capacity of 1129–1313 mA h g−1 but also a low open-circuit voltage (0.45–0.87 V), which is important to achieve high energy density. AIMD simulations have confirmed the excellent cyclability of BxN electrodes during reversible lithiation/delithiation. These results suggested that the BxN electrode could be used as a new lightweight SIB anode with high capacity, cyclability, and desired rate performance. [ABSTRACT FROM AUTHOR]

Traditional shape memory polymers (SMPs) could avoid large volume trauma during implantation; however, for bone repair, scaffolds with high porosity and biomineralization are essential to promote bone regeneration. A novel porous composite scaffold with high biomineralization activity was developed by sequential gas foaming and a freeze–drying method. The results showed that the cross-linked block structure of the polymer matrix presented excellent shape memory properties, and osteogenesis was promoted by citrate functionalized amorphous calcium phosphate (CCACP). CCACP improved the mechanical strength of the scaffold, and the synergistic effect of CCACP and PEG promotes hydrophilicity and further promoted cell adhesion. Bending experiments indicated that the shape-memory effect of the scaffolds could be varied by varying the CCACP content. In addition, hydroxyapatite deposition was sped up as CCACP accelerated the mineralization of the scaffolds. Moreover, the result of the CCK-8 assessment suggested that composite scaffolds exhibited high biocompatibility, and the cells extended out abundant filopodia to adhere onto the scaffolds. In rat bone defect models, the obtained scaffolds promoted new bone formation compared to the control group. The developed composite scaffolds show potential for minimally invasive bone repair application. [ABSTRACT FROM AUTHOR]

Na-ion batteries (SIBs) are emerging as a promising alternative to Li-ion batteries for large-scale energy storage in light of abundant Na resources and their low cost. Development of appropriate electrode materials that can conquer some critical issues such as low theoretical storage capacity and sluggish redox kinetics resulting from the larger radius of Na is urgently needed for their practical applications. In this work, boron-rich 2D B x N ( x = 2, 3, and 5) has been explored as promising anode materials for high-performance SIBs based on density functional theory calculations. B x N electrodes exhibit moderate affinity toward Na-ions with adsorption energies of -0.41 to -1.21 eV, which allows stable Na-ion intercalation without the formation of metal dendrites. Moreover, both B 3 N and B 5 N deliver low diffusion barriers (0.28 and 0.08 eV) for Na-ion migration, guaranteeing a high charging/discharging rate. More importantly, these B x N anodes exhibit not only a remarkably high theoretical capacity of 1129-1313 mA h g -1 but also a low open-circuit voltage (0.45-0.87 V), which is important to achieve high energy density. AIMD simulations have confirmed the excellent cyclability of B x N electrodes during reversible lithiation/delithiation. These results suggested that the B x N electrode could be used as a new lightweight SIB anode with high capacity, cyclability, and desired rate performance.