Transformation from 3D Boron Organic Polymers to 1D Nanorod Arrays: Loading Highly Dispersed Nanometal for Green Catalysis

Chaotropic Effect-Induced Self-Assembly of the Malachite Green and Boron Cluster for Toxicity Regulation and Photothermal Therapy

Malachite green (MG), a toxic antibacterial agent, is widely used in the farming industry. Effectively regulating the biotoxicity of this highly water-soluble cationic dye is challenging. Here, we present a novel strategy to reduce the biotoxicity of MG through the self-assembly of MG and the closo-dodecaborate cluster ([B12H12]2-) driven by the chaotropic effect. [B12H12]2- and MG in an aqueous solution can rapidly form an insoluble cubic-type supramolecular complex (B12-MG), and the original toxicity of MG is completely suppressed. Surprisingly, this supramolecular complex, B12-MG, has a strong UV-vis absorption peak at 600-800 nm and significant photothermal conversion efficiency under 660 nm laser irradiation. On this basis, B12-MG, the supramolecular complex, can be used as an efficient photothermal agent for antimicrobial photothermal therapy (PTT) both in vitro and in vivo. As a molecular chaperone of MG, [B12H12]2- not only can be applied as an antidote to regulate the biotoxicity of MG but also provides a novel method for the construction of photothermal agents for PTT based on the chaotropic effect.

Functionalization of Dodecaborates by Mild and Efficient Pd-Catalyzed Formation of B-C Bonds with Boronic Acids

Hybrid organic-inorganic molecules have recently received great interest due to their unique properties, which give access to their implementation in biological and material sciences. Herein, a new synthetic approach for the direct-linkage of the purely inorganic dodecaborate cluster to organic building blocks through B-C bond is established, using boronic acids as functional groups on the organic moiety, reacting under Suzuki-Miyaura coupling conditions with iodo-undecahydridododecaborate. The choices of ligand (DavePhos) and solvent (N-methylpyrrolidone for electron-poor, CD3 CN for electron-rich groups) are essential for the successful coupling. Ultimately, the newly described methodology is found to be functional-group tolerant covering a wide spectrum of substrates including electron-poor arenes.

Controllable Synthesis of Cobalt-Containing Nanosheet Array-Like Ternary CuCoAl-LDH/rGO Hybrids To Boost the Catalytic Efficiency for 4-Nitrophenol Reduction

A series of Co-doped ternary Cu_xCo_3-xAl-layered double hydroxide (LDH)/rGO nanosheet array hybrids (x = 0.5, 1.0, 1.5, and 2.0) were successfully prepared using the preconditioned pH value aqueous-phase coprecipitation strategy. The Cu_xCo_3-xAl-LDH/rGO hybrids are featured as hexagonal CuCoAl-LDH nanosheets in situ anchoring onto both sides of the rGO surface in an ab-plane vertically interlaced growth pattern. The Cu_xCo_3-xAl-LDH/rGO hybrids show excellent activity for the complete conversion of 4-nitrophenol to 4-aminophenol, especially Cu_1.5Co_1.5Al-LDH/rGO with the highest k_app value of 49.2 × 10^-3 s^-1 and TOF of 232.8 h^-1, clearly higher than most copper-containing samples in the literature and even some precious ones. Thermodynamic analysis was carried out, and the values of Ea, ΔH^#, ΔS^#, and ΔG^# were estimated. The best activity of Cu_1.5Co_1.5Al-LDH/rGO can be mainly ascribed to the in situ-formed ultrafine Cu₂O NPs (∼4.3 nm) along with a small amount of Cu⁰ species, the electron transfer effect induced by atomically dispersed Co²⁺ species leading to the formation of electron-rich Cu species along with the Co²⁺/Co³⁺ redox couple, the strong Cu₂O-CuCoAl-LDH-rGO synergy upon the nanosheet array morphology with a high surface area and pore volume, and enhanced adsorption of reactants upon π-π stacking via an rGO layer. Meanwhile, the Cu_1.5Co_1.5Al-LDH/rGO exhibits an excellent universality and good cycling stability for 10 continuous runs. The Cu_1.5Co_1.5Al-LDH/rGO also shows superior efficiency in the catalytic reduction of 4-NP solution with a high concentration (20 mM) and displays excellent reduction performance in the fixed-bed test, implying the potential applications of the current Co-doped hierarchical ternary Cu-based LDH/rGO hybrids in the continuous treatment of practical wastewater.

Single-atom niobium doped BCN nanotubes for highly sensitive electrochemical detection of nitrobenzene

Herein, single-atom niobium-doped boron–carbon–nitrogen nanotubes (SANb-BCN) were synthesized and utilized to fabricate an electrochemical sensor for the detection of nitrobenzene (NB), an environmental pollutant. SANb-BCN were characterized through scanning transmission electron microscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction analysis, and Raman spectroscopy. The Nb-BNC material modified on a glassy carbon electrode (GCE) showed an excellent electrochemical response behavior toward NB. The SANb-BCN-modified GCE (SANb-BCN/GCE) gave rise to a prominent NB reduction peak at −0.6 V, which was positively shifted by 120 mV from the NB reduction peak of the bare GCE. Furthermore, the NB peak current (55.74 μA) obtained using SANb-BCN/GCE was nearly 42-fold higher than that using the bare GCE (1.32 μA), indicating that SANb-BCN/GCE is a highly sensitive electrochemical sensor for NB. An ultralow limit of detection (0.70 μM, S/N = 3) was also achieved. Furthermore, the SANb-BCN/GCE sensor was found to possess favorable anti-interference ability during NB detection; thus, the presence of various organic and inorganic coexisting species, including Mg²⁺, Cr⁶⁺, Cu²⁺, K⁺, Ca²⁺, NH⁴⁺, Cd²⁺, urea, 1-bromo-4-nitrobenzene, 3-hydroxybenzoic, terephthalic acid, 1-iodo-4-nitrobenzene, and toluene, minimally affected the NB detection signal. Notably, the SANb-BNC sensor material exhibited high sensitivity and specificity toward detection of NB in environmental samples. Thus, the use of the proposed sensor will serve as an effective alternative method for the identification and treatment of pollutants.

Herein, single-atom niobium-doped boron–carbon–nitrogen nanotubes (SANb-BCN) were synthesized and utilized to fabricate an electrochemical sensor for the detection of nitrobenzene (NB), an environmental pollutant.

BCN-Encapsulated Nano-nickel Synergistically Promotes Ambient Electrochemical Dinitrogen Reduction

The electricity provided by solar or wind power can drive nitrogen in the atmosphere, combining with ubiquitous water to form ammonia, and distributed production methods can alleviate the irreversible damage to the environment caused by the energy-intensive Haber-Bosch process. Here, we have designed a novel Ni-doped BCN heterojunction (S/M-BOPs-1) as a catalyst for the electrochemical nitrogen reduction reaction (NRR). The ammonia yield rate and Faraday efficiency in NRR driven by S/M-BOPs-1 reach up to 16.72 μg^-1 h^-1 cm^-2 and 13.06%, respectively. Moreover, S/M-BOPs-1 still maintains high NRR activity and excellent stability after recycling for eight times and long-time operation of 12 h. Using density functional theory calculations, we reveal a possible NRR path for N₂ to NH₃ on Ni, BCN, and the S/M-BOPs-1 composite surfaces. The interaction between the BCN matrix and Ni nanoparticles promotes a synergetic effect for the electrochemical NRR efficiency due to the partial electron transfer from the Ni particles to BCN that inhibits hydrogen evolution reaction and decreases the rate-determining step on Ni surfaces toward NRR by ∼1.5 times. Therefore, efficient NRR performance can be achieved by tuning the electronic properties of non-noble metals via the formation of a heterointerface.