(Ni,Mg)3Si2O5(OH)4 Solid-Solution Nanotubes Supported by Sub-0.06 wt % Palladium as a Robust High-Efficiency Catalyst for Suzuki–Miyaura Cross-Coupling Reactions

Synthesis of Mesoporous Copper Aluminosilicate Hollow Spheres for Oxidation Reactions

Hollow functional metal silicate materials have received the most interest due to their large inner space, permeable and functional shell, lighter density, and better use of material compared to their solid counterparts. While tremendous success has been made in the synthesis of individual metal silicates with uniform morphology, the synthesis of multiphase hollow silicates has not been explored yet, although their direct applications could be promising. In this study, mesoporous aluminosilicate spheres (MASS) are transformed to submicrometer copper aluminosilicate hollow spheres (CASHS) via a one-pot hydrothermal process. CASHS has a hollow interior with Cu-Al-Si thorn-like moieties in a lamellar structure on its outer shell. The structure and morphology of CASHS are unique and different from the previously reported tubular copper silicates that are emanated from Stöber silica spheres. Herein, we also demonstrate that the extent of hollowing in CASHS can be attained by controlling the aluminum content of pristine MASS, highlighting the existence of parameters for in situ controlling the shell thickness of hollow materials. The application of CASHS as a potential heterogeneous catalyst has been directed to important oxidation processes such as olefin oxidation and the advanced oxidation process (AOP). In cyclohexene oxidation, for instance, high selectivity to cyclohex-2-en-1-one is achieved under moderate conditions using tert-butyl hydroperoxide as the oxidant. CASHS is a robust heterogeneous catalyst and recyclable for this reaction. CASHS-derived catalysts also favor AOP and enhance the removal of cationic dyes together with H₂O₂ through an adsorption-degradation process.

Ultralong Ca2B2O5·H2O nanowires: water-bath pretreated eco-friendly hydrothermal synthesis, optical and rare earth-doped photoluminescence properties

A facile water-bath pretreated hydrothermal route is developed for ultralong Ca₂B₂O₅·H₂O nanowires (length: <230 μm) as a promising photoluminescent host candidate.

When Layered Nickel-Cobalt Silicate Hydroxide Nanosheets Meet Carbon Nanotubes: A Synergetic Coaxial Nanocable Structure for Enhanced Electrocatalytic Water Oxidation

Developing robust earth-abundant electrocatalysts for oxygen evolution reaction (OER) is an ongoing scientific challenge, which is coupled with a number of important electrochemical processes and many key renewable energy systems, such as water splitting, rechargeable metal-air batteries, and regenerative fuel cells. Here, we proposed a rational design and fabrication of the synergetic coaxial nanocable structures by intimate growth of the layered nickel-cobalt silicate hydroxide nanosheets on the outer surfaces of multiwalled carbon nanotubes (MWCNTs@NCS) and demonstrated their high efficiency in electrocatalytic OER from water splitting. The electrocatalytic activities of the MWCNTs@NCS were found to be significantly higher than that of bare NCS and pristine MWCNTs, synergetically determining by such the constituted individual components. Among them, the MWCNTs@NCS-2 exhibited best electrocatalytic OER performance, showing a small OER onset potential, large anodic current and long-term durability, which was favorably comparable to the previously reported NiCo-based OER electrocatalysts in alkaline electrolytes. To the best of our knowledge, this was a first example on the earth-abundant metal silicate hydroxides utilized in electrochemical water splitting.

Hierarchical γ-BaB2O4 hollow microspheres: surfactant-assisted hydrothermal formation, phase conversion, optical properties and application as adsorbents

A facile EDTA-2Na assisted hydrothermal route was developed for hierarchical γ-BaB₂O₄ hollow microspheres self-assembled from nanorods, with excellent thermostability and satisfactory performance for the removal of Pb²⁺ ions from mimic waste water.

Pyridinyl functionalized MCM-48 supported highly active heterogeneous palladium catalyst for cross-coupling reactions

Pyridinyl functionalized MCM-48-supported Pd-catalyst efficiently (0.013–0.025 mol%) promoted Heck, Suzuki and Sonogashira cross-coupling reactions. Moreover, the catalyst was reused five times without significant loss of its activity.

Morphology-controllable Li2SiO3 nanostructures

Hydrothermal synthesis of lithium metasilicate (Li₂SiO₃) has been systematically studied in aqueous alkaline environments by varying the Li/Si molar ratios of the solid materials and the hydrothermal temperatures.