Latest ArticlesA novel biodegradable material, Se@PLA, was designed and prepared via the selenization reaction of polylactic acid using NaHSe as the selenization reagent. This material shows excellent antibacterial activity (EC50 = 13.38 µg/mL) against Xanthomonas oryzae pv. Oryzae, which is a highly destructive pathogen responsible for rice bacterial blight. Se@PLA induces oxidative stress in bacteria, leading to the rupture of bacterial cell membranes and eventual death. Moreover, Se@PLA can significantly inhibit the motility of bacteria and is low toxic to soil and aquatic organisms. This work provides an effective method for preventing and controlling rice bacterial blight, and reveals the great potential of using Se@PLA as an alternative next generation plant bactericide.
Tetracycline (TC) as a typical emerging pollutant is becoming a serious threat to the environment and human health. A combined advanced oxidation technology of UV/Ozone (O3)/peroxydisulfate (PDS) process was developed to explore an efficient and economic treatment process of TC in wastewater. Furthermore, the reactive sites and transformation pathways of TC were explored and the toxicity of the intermediates was quantified with a quantitative structure-activity relationship (QSAR) assessment. The degradation performance of TC was substantially enhanced in UV/O3/PDS process with a kobs of 0.0949 min−1, which was 2.3 times higher than UV/O3 and 3.2 times than sole UV. The results demonstrated that there was a superior synergistic effect of PDS on UV/O3 processes for the degradation of TC. Electron paramagnetic resonance (EPR) analysis and quenching experiments show that •OH, SO4•−, O2•− and 1O2 all contributed to TC degradation in the UV/O3/PDS process and exhibited a synergistic effect, which inhibited the generation of harmful products. In addition, the UV/O3/PDS system can effectively degrade TC in a wide range of substrate concentrations and pH, and also showed excellent adaptability to various concentrations of anions (Cl− and HCO3−). This study proves the feasibility of UV/O3/PDS process for treating TC contaminated wastewater with complicated water matrix.
The first example of sono-photocatalytic bond formation was reported. With both visible light and ultrasound wave as the energy, various 3-aminoquinoxalin-2(1H)-ones were efficiently obtained with good functional group tolerance in the absence of any additive or external photocatalyst. Compared with the conventional photocatalysis, sono-photocatalysis not only dramatically improved the reaction rates and yields, but also reduced energy consumption.
Charge-transfer (CT) stoichiometric cocrystals are promising choice of organic materials for unveiling the structure-property relationship. However, due to the contradiction between large CT degree required for strong NIR absorption and flexible molecular stacking, construction of stoichiomorphism-based cocystals with near-infrared (NIR) photothermal property remains challenging. Herein, the first example of stoichiomorphism-based photothermal cocrystals were accomplished through the adaptive assembly of 3,3′,5,5′-tetramethylbenzidine (TMB) donor and 1,2,4,5-tetracyanobenzene (TCNB) acceptor. The selective cocrystallization could be controlled by varying the donor-acceptor stoichiometries via a surfactant-assisted method, resulting in two cocrystals with 1:1 (T1C1) and 1:2 (T2C1) stoichiometries. The absorbance intensity of T1C1 at 808 nm was nearly twice that of T2C1, while the photothermal conversion efficiency (PCE) of the former was 60.3% ± 0.6%, approximately 80% of that for the latter (75.5% ± 2.6%), which might be caused by the different intermolecular interactions in distinct molecular stacking patterns. Notably, both excellent PCEs of stoichiometric cocrystals were attributed to the nonradiative transition process, including internal conversion and charge dissociation processes, as elucidated by femtosecond transient absorption spectroscopy measurements. Furthermore, T1C1 was used as an NIR heater for preparing agarose-based photothermal hydrogel, showing great potential for light-controlled in-situ gelation. This strategy of balancing the CT degree and molecular packing orientation not only uncovered the relationship between stoichiometric stacking and photothermal property, but also provided an opportunity to develop advanced organic optoelectronic materials.
Directed self-assembly has been used to create micro-nano scale patterns, including chiral periodic structures of organic molecules, for potential applications in optics, photonics, metamaterials, and medical and sensing technologies. This study presents a straightforward approach for fabricating large-scale chiral grating porphyrin assemblies through template-assisted techniques. The solution of tetrakis(4-sulfonatophenyl)porphyrin (TPPS) was induced by chiral amino acids (L/D-arginine and L/D-serine) to self-assemble into highly ordered chiral grating structures with the assistance of sodium dodecyl sulfate (SDS). The structures show precise line widths (5.5 µm) and gaps (18 µm). Using in situ optical microscopy and second harmonic generation (SHG) microscopy, the chiral characteristics and dynamic evolution of the template-assisted self-assembly are investigated. It is found that the chirality of amino acids induced TPPS self-assembled into chiral structures and the liquid contraction interface significantly enhanced the chirality of the assemblies. This study is significant for understanding the mechanism of chiral evolution and designing novel micro-nano materials with predetermined chiral properties.
The electrochemical oxidation of 5-hydroxymethylfurfural (HMF) to valuable chemicals is an efficient way to upgrade biomass molecules and replace traditional catalytic synthesis. It is crucial to develop efficient and low-cost earth-abundant electrocatalysts to enhance catalytic performance of HMF oxidation. Herein, a new type of two-dimensional (2D) hybrid arrays consisting of NiFe layered double hydroxides (LDH) nanosheets and bimetallic sulfide (NiFeS) is constructed via interface engineering for efficient electrocatalytic oxidation of HMF to 2, 5-furandicarboxylic acid (FDCA). The preparation process of 2D NiFe LDH/NiFeS with ultrathin heterostructure involves in anchoring a Co-based metal-organic framework (Co MOF) as template onto the carbon cloth (CC) via in-situ growth, formation of NiFe LDH on the surface of Co MOF and subsequent partial sulfidation. The electrocatalyst of NiFe LDH/NiFeS exhibits outstanding performance towards HMF oxidation, about 98.5% yield for FDCA and 97.2% Faraday efficiency (FE) in the alkaline electrolyte with 10 mmol/L HMF, as well as excellent stability retaining 90.1% FE for FDCA after six cycles test. Moreover, even at an HMF concentration of 100 mmol/L, the yield and FE for FDCA remain high at 83.6% and 93.6%, respectively. These findings highlight that 2D heterostructure containing abundant interfaces between NiFe LDH nanosheets and NiFeS can enhance the intrinsic activity of LDH and thus promote the oxidation reaction kinetics. Additionally, the synergistic effect of the bimetallic NiFe compounds also improved the selectivity of HMF conversion to FDCA. Our present work demonstrates that constructing 2D ultrathin heterostructure of NiFe LDH/NiFeS is a facile strategy via interface engineering to enhance the intrinsic activity of LDH electrocatalysts, which would open new avenues toward low-cost and advanced 2D nanocatalysts for sustainable energy conversion and electrochemical valorization of biomass derivatives.
Tryptophan (Trp) is an essential amino acid that plays a critical role in human physiology. The increasing demand for Trp has created a highly promising market, underscoring the urgent necessity for the development of efficient strategies for the simultaneous detection and uptake of tryptophan. Herein, we report an expanded "Texas-sized" molecular box (An-TxSB), which incorporates luminescent anthracene bridging subunits and molecular recognition motifs. This luminescent molecular box demonstrates exceptional sensitivity to Trp in water, permitting its precise quantification with a notably low limit of detection (LOD) of 0.42 µmol/L. Moreover, An-TxSB facilitates the proficient uptake of Trp from simulated water samples, thereby revealing an impressive Trp adsorption capacity of up to 226.0 µmol/g.
Environmental endocrine disruptors, represented by bisphenol A (BPA), have been widely detected in the environment, bringing potential health risks to human beings. Nitrogen-containing biocarbon catalyst can activate peroxymonosulfate (PMS) to degrade BPA in water, but its active sites remain opaque. Herein, in this work, nitrogen-containing biochar, i.e., CNedge, enriched with graphitic-N defects at the edges was prepared by one-pot co-pyrolysis of chitosan and potassium carbonate. The results showed that the CNedge/PMS system can effectively degrade 98% of BPA (50 mg/L). The electron transfer based non-radical oxidation mechanism was responsible for BPA degradation. Edge graphitic-N doping endows biochar with strong electron transfer ability. The catalyst had good recovery and reuse performance. This catalytic oxidation was also feasible for other refractory pollutants removal and worked well for treating practical wastewater. This work may provide valuable information in unraveling the N doping configuration-activity relationship during activating PMS by biochar.
In this study, a series of arylene-bridged bis(benzimidazolium)triflates 1–62+·2[OTf–] were synthesized by grafting different π-linkers with benzimidazolium scaffolds. Among them, compound 12+·2[OTf–] with anthracene as the linker exhibited remarkable electron transfer capabilities across four distinct redox states. The inclusion of an anthracene unit as the π-linker contributes to its exceptional redox and optoelectronic characteristics. Consequently, 12+·2[OTf–] was successfully utilized as both an electrochromic molecule in an ECD under applied voltage for the first time, and a highly efficient photocatalyst for the formation of carbon–phosphorus bonds via visible-light-induced cross-dehydrogenative coupling reactions.
Multicharged supramolecular assemblies based on luminescent macrocycle play an important role in extending their optical properties and functions. Herein, we reported macrocyclic supramolecular assemblies based on luminescent terphen[3]arene sulfate (TP[3]AS) and tetraphenylethylene pyridinium (TPE-4Py) through electrostatic interactions, host-guest encapsulation and π-π stacking interactions. Förster resonance energy transfer (FRET) process from TP[3]AS to TPE-4Py was achieved with the energy transfer efficiency of 99.9%, accompanied by TPE-4Py fluorescence emission bathochromic shifted of 15 nm and enhanced by 1.68 times in PBS solution. In contrast, other non-luminescent sulfato-β-cyclodextrin and sulfobutylether-β-cyclodextrin only can enhance the fluorescence intensity of TPE-4Py without bathochromic shift. Due to the strong fluorescence and good stability of TPE-4Py@TP[3]AS, it can be used for optical imaging in living cells, which provided an effective approach for the construction of assembling-confined luminescent biomaterials.