Efficient and selective extraction of uranium (U(VI)) from seawater is essential for sustainable nuclear power production. This study reports a novel adsorbent zeolitic imidazolate framework (ZIF)-67@SiO₂-A/polyacrylamide (PAM) which was synthesized by grafting the core–shell metal–organic frameworks (MOFs)-based nanostructures coated with the 3-aminopropyl triethoxysilane (APTES) functionalized SiO₂ (SiO₂-A) onto PAM hydrogel. The SiO₂ shell was grown on the surface of MOF, which improved the acid-base resistance of MOF. The introduction of ZIF-67@SiO₂-A enhances the specific surface area and adsorption efficiency of the PAM. The ZIF-67@SiO₂-A/PAM shows remarkable adsorption capacity, fast adsorption kinetics, and good reusability for uranium. It has excellent adsorption property (6.33 mg·g⁻¹, 30 d) in natural seawater. The X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR), energy dispersive spectroscopy (EDS) mappings, and density functional theory reveal that the coordination by N and O in ZIF-67@SiO₂-A/PAM with uranium is the main mechanism of uranium adsorption. Thus, ZIF-67@SiO₂-A/PAM has great potential to capture uranium from natural seawater.

Efficient capture of uranium(VI) (U(VI)) from seawater is of great significance to the sustainable development of nuclear energy and environmental protection, which is also a serious challenge at present. In this study, hollow Zn/Co zeolitic imidazolate framework (H-ZIF) was decorated on polyacrylamide/sodium alginate (PAM/SA) hydrogel by chelating and covalently crosslinking, and a new type of PAM/SA/H-ZIF hydrogel was synthesized. The combination of PAM/SA and H-ZIF gives PAM/SA/H-ZIF hydrogel excellent mechanical properties, good stability, and abundant surface functional groups, which is beneficial to improving the adsorption properties. The extraction amount of U(VI) by PAM/SA/H-ZIF is 171.14 mg·g⁻¹ at C₀ = 99.52 mg·L⁻¹ and pH = 5.0. The adsorption equilibrium is reached in 120 min and the adsorption process fits well with Langmuir isotherm model and pseudo-second-order rate equation. The PAM/SA/H-ZIF also showed good recyclability and stability after 10 cycles of adsorption–desorption. More importantly, the rate of uranium adsorption is 0.196 mg·g⁻¹·day⁻¹ after 30 days, which implies that the PAM/SA/H-ZIF could serve as a potential adsorbent for the development of uranium capture from seawater.

Dendritic mesoporous silica nanoparticles own three-dimensional center-radial channels and hierarchical pores, which endows themselves with super-high specific surface area, extremely large pore volumes, especially accessible internal spaces, and so forth. Dissimilar guest species (such as organic groups or metal nanoparticles) could be readily decorated onto the interfaces of the channels and pores, realizing the functionalization of dendritic mesoporous silica nanoparticles for targeted applications. As adsorbents and catalysts, dendritic mesoporous silica nanoparticles-based materials have experienced nonignorable development in CO₂ capture and catalytic conversion. This comprehensive review provides a critical survey on this pregnant subject, summarizing the designed construction of novel dendritic mesoporous silica nanoparticles-based materials, the involved chemical reactions (such as CO₂ methanation, dry reforming of CH₄), the value-added chemicals from CO₂ (such as cyclic carbonates, 2-oxazolidinones, quinazoline-2,4(1H,3H)-diones), and so on. The adsorptive and catalytic performances have been compared with traditional silica mesoporous materials (such as SBA-15 or MCM-41), and the corresponding reaction mechanisms have been thoroughly revealed. It is sincerely expected that the in-depth discussion could give materials scientists certain inspiration to design brand-new dendritic mesoporous silica nanoparticles-based materials with superior capabilities towards CO₂ capture, utilization, and storage.