Boron nitride-alginate coordination interactions enabling hydrogels with enhanced mechanical strength and heat resistance.

Developing large-scale hydrogels with high tensile strength and robust mechanical properties is an intricate challenge of great industrial significance. In this study, we demonstrate an efficient method for producing nanocomposite hydrogels with extraordinary mechanical properties. Our approach involves a two-step process: an initial stage of pre-cross-linking boron nitride (BN)-enriched pre-gel sodium alginate, followed by cross-linking with metal ions. In stark contrast to conventional sodium alginate hydrogels (SA), our newly formulated 'BS hydrogel' exhibited an impressive tensile strength exceeding 41 MPa and improved thermal resistance. Moreover, the reconstituted BS hydrogel exhibited tensile strengths ranging from 47 to 96 MPa and elastic moduli ranging from 199 to 1184 MPa, depending on the cross-linking metal ions. These findings indicate the multifaceted potential of the BS hydrogel, which is poised to revolutionize many applications and represents a significant step forward in hydrogel technology for industrial applications.

Accurate assessment of electrocatalytic carbon dioxide reduction products at industrial-level current density.

During the electrocatalytic CO2 reduction reaction, the faradaic efficiency of products seriously deviates from 100% due to the misjudgment of outlet flow, especially at industrial-level large current density. In this work, several modified equations and internal standard methods are recommended to calibrate the thermal mass flowmeter and establish benchmarks for CO2 reduction performance assessment.

Charged Boron Nitride Nanosheet Membranes for Improved Organic Solvent Nanofiltration.

Two-dimensional nanomaterial-based membranes have earned broad attention because of their excellent capability of separation performance in a mixture that can challenge the conventional membrane materials utilized in the organic solvent nanofiltration (OSN) field. Boron nitride (BN) nanosheet membranes have displayed superb stability and separation ability in aqueous and organic solutions compared to the widely researched analogous graphene-based membranes; nevertheless, the concentration polarization of organic dye pollutants fades their separation performance and eclipses their potential adoption as a feasible technology. Herein, PDDA-modified BN (PBN) and sodium alginate-modified BN (SBN) nanosheet membranes with a thinner laminar structure are facially fabricated to improve the molecule separation performance compared to that of the pristine BN membrane. In aqueous separation application, the SBN membranes (2 µm) can reject positively charged dyes up to 100% and the PBN membrane (2 µm) could reject negatively charged dyes up to 100%. Impressively, the PBN membranes (3 µm) and SBN membranes (3 µm) demonstrate record high performances in OSN, with a permeance of 809 L m-2 h-1 bar-1 and 97.71% rejection to acid fuchsin in acetonitrile and 290 L m-2 h-1 bar-1 and 94.94% rejection to Azure B in dimethyl sulfoxide, respectively. The charged PBN and SBN nanosheet membranes demonstrate stable separation capability, exhibiting their potential for practical water and organic solvent purification processes.

Capillary-Bound Dense Micelle Brush Supports for Continuous Flow Catalysis.

Flow reactors are appealing alternatives to conventional batch reactors for heterogeneous catalysis. However, it remains a key challenge to firmly immobilize the catalysts in a facile and flexible manner and to simultaneously maintain a high catalytic efficiency and throughput. Herein, we introduce a dense cylindrical micelle brush support in glass capillary flow reactors through a living crystallization-driven self-assembly process initiated by pre-immobilized short micelle seeds. The active hairy corona of these micellar brushes allows the flexible decoration of a diverse array of nanocatalysts, either through a direct capture process or an in situ growth method. The resulting flow reactors reveal excellent catalytic efficiency for a broad range of frequently utilized transformations, including organic reductions, Suzuki couplings, photolytic degradations, and multistep cascade reactions, and the system was both recyclable and durable. Significantly, this approach is readily applicable to long capillaries, which enables the construction of flow reactors with remarkably higher throughput.

Hydrogenation of nitroarenes into aromatic amines over Ag@BCN colloidal catalysts.

The present work reports that two-dimension layered ternary boron carbon nitrogen nanosheets can serve as good carriers to support and disperse noble metal nanoparticles. The Ag@BCN colloids have thus been prepared by attaching Ag nanoparticles on the surfaces of BCN nanosheets. The detailed structures of the Ag@BCN samples were investigated by X-ray diffraction, transmission electron microscopy, atomic force microscope, infrared, and X-ray photoelectron spectroscopy. It is found that the surface NH groups of BCN nanosheets are beneficial for the attachment of Ag nanopaprticles. Compared with the conventional organic capping compounds, the two dimensional planar BCN nanosheets endow the attached nanoparticle with the high active surfaces. Moreover, the hydrogenation of nitroarenes into the corresponding aromatic amines can be highly achieved over Ag@BCN colloids by NaBH4. In particular, the apparent activation energy of the conversion reaction of p-nitroaniline to p-phenylenediamine was found to be 76.0kJ/mol over the Ag@BCN colloids with 3wt% Ag content. Our results may provide a new approach for the design noble metal based composites and find the practical application for the hydrogenation of nitroarenes.

Hexagonal boron nitride nanoplates as emerging biological nanovectors and their potential applications in biomedicine.

The application of nanomaterials in the biological and medical areas has attracted great attention. Cytotoxicity, stability and solubility are the prerequisites for a nanomaterial to be considered for application in the field of biomedicine. Here, we suggest a simple method to produce highly dispersed water-soluble ultrathin h-BN nanoplates whose size measures ca. 30-60 nm in diameter and 1.6 nm in thickness. Moreover, we demonstrate that h-BN nanoplates can act as a reliable biological nanovector to carry proteins by cross-linking immobilization. Furthermore, the biocompatibility of h-BN nanoplates has also been explored via an apoptosis assay. In addition, a successful attempt has been made to investigate the potency of h-BN nanoplates as an immunostimulating adjuvant in a mouse immunization experiment. Preliminary results show that the level of antibody response stimulated by an antigen protein (bovine serum albumin) linked with h-BN is ca. 4 times higher than that by the antigen protein alone. This work gives evidence that water-soluble h-BN nanoplates are of high biocompatibility and low reactogenicity and therefore they can serve as an excellent biomedical platform for nanoparticle-biomolecular interactions. They preserve and even enhance the bioacitivities of the cross-linked antigen proteins, which strongly suggests their use in nanoparticle vaccine design.

Boron nitride encapsulated copper nanoparticles: a facile one-step synthesis and their effect on thermal decomposition of ammonium perchlorate.

Reactivity is of great importance for metal nanoparticles used as catalysts, biomaterials and advanced sensors, but seeking for high reactivity seems to be conflict with high chemical stability required for metal nanoparticles. There is a subtle balance between reactivity and stability. This could be reached for colloidal metal nanoparticles using organic capping reagents, whereas it is challenging for powder metal nanoparticles. Here, we developed an alternative approach to encapsulate copper nanoparticles with a chemical inertness material--hexagonal boron nitride. The wrapped copper nanoparticles not only exhibit high oxidation resistance under air atmosphere, but also keep excellent promoting effect on thermal decomposition of ammonium perchlorate. This approach opens the way to design metal nanoparticles with both high stability and reactivity for nanocatalysts and their technological application.

Dispersed Cu2O octahedrons on h-BN nanosheets for p-nitrophenol reduction.

We demonstrate here that two-dimensional boron nitride (h-BN) nanosheets can be employed as a robust supporting substrate to incorporate function metal oxides. The Cu2O@h-BN composites are thus obtained by dispersing Cu2O octahedrons on the surfaces of h-BN nanosheets. The -OH and -NH groups on the surfaces of h-BN nanosheets are found to be beneficial for anchoring Cu2O octahedrons. Moreover, the Cu2O@h-BN composites exhibit superior activity for the reduction of p-nitrophenol to pure Cu2O crystals and h-BN nanosheets. The h-BN component in the composites plays a critical role in the formation and adsorbing of the p-nitrophenolate ions, and, at the same time, Cu2O components react with brohydride ions and transfer a surface hydrogen species and electrons, resulting in the reduction of p-nitrophenol into p-aminophenol. Our results provide a new approach for the rational design and development of metal oxides composites and open the way to a range of important applications of h-BN-based materials.