Latest ArticlesFabrication of multifunctional nanoplatform to in situ monitor Fenton reaction is of vital importance to probe the underlying reaction process and design high-performance catalyst. Herein, a hybrid catalyst comprising of single-crystalline Au nanoparticles (SC Au NPs) on reduced graphene oxide (RGO) sheet was prepared, which not only exhibited an excellent 1O2 mediated Fenton-like catalytic activity in promoting rhodamine 6G (R6G) degradation by activating H2O2, but also displayed a sensitive surface-enhanced Raman spectroscopy (SERS) detection performance to R6G with a linear response range from 1.0 × 10-8 mol/L to 1.0 × 10-5 mol/L thus providing a powerful and versatile nanoplatform for in situ SERS monitoring Fenton-like catalytic reaction. The integration of catalytic and SERS activities into a single nanostructure are expected to provide great potentials for practical applications in environmental catalysis.
In recent years, MoS2 catalyzed/cocatalyzed Fenton/Fenton-like systems have attracted wide attention in the field of pollution control, but there are few studies on the effect of H2O2 feeding way on the whole Fenton process. Here, we report a new type of composite catalyst (MoS2-Fex) prepared in a simple way with highly dispersed iron to provide more active sites. MoS2-Fex was proved to possess selectivity for singlet oxygen (1O2) in effectively degrading sulfadiazine with a wide pH adaptability (4.0~10.0). Importantly, the mechanism of the interaction between H2O2 and MoS2 on the Fenton reaction activity was revealed through the combination of experiment and density functional theory (DFT) calculations. Compared to the traditional "a large amount for one time" feeding way of H2O2, the "small amount for multiple times" of H2O2 feeding way can increase the degradation rate of sulfadiazine from 36.9% to 91.1% in the MoS2-Fex heterogeneous Fenton system. It is demonstrated that the "small amount for multiple times" of H2O2 feeding way can reduce the side reaction of decomposition of H2O2 by MoS2 and effectively improve the utilization rate of H2O2 and the stability of MoS2-Fex. Compared with Fe2O3-based Fenton system, MoS2-Fex can significantly save the amount of H2O2. Compared with nano-iron powder, the formation of iron sludge in MoS2-Fex system was significantly reduced. Furthermore, long-term degradation test showed that the MoS2-Fe75/H2O2 system could maintain the effectiveness of degrading organic pollutants for 10 days (or even longer). This study has a guiding significance for the large-scale treatment of industrial wastewater by improved Fenton technology in the future.
Regulation of chemical composition and nanostructure, such as the introduction of dopant into two-dimensional nanomaterials, is a general and valid strategy for the efficient electrocatalyst design. In this work, Co4S3/Co9S8 nanosheets, with an ultrathin layer structure, were successfully synthesized via an efficient solvothermal process combined with ultrasonic exfoliation. Different metal ions (M = Fe3+, Cr3+, Mn2+ and Ni2+) were then doped by a simple cation exchange method and the effects of different dopants on the OER activities of Co4S3/Co9S8 NS were further investigated in alkaline media. The corresponding results implied that M-doped Co4S3/Co9S8 NS (M = Fe3+, Cr3+, Mn2+ and Ni2+) exhibited different electrocatalytic properties. Evidenced by XPS spectra, the different OER activities were mainly aroused by the redistribution of charge at the interface due to an electronic interaction between the doped metal ions and Co4S3/Co9S8 NS.
Here, we report a finding on light-mediated CO2-responsiveness. It is found on the microgels that are made of side-chain type metallopolymers containing metalla-aromatics. Turbidity and laser light scattering studies on dilute aqueous dispersion of these microgels in dark indicate high CO2-responsivity, but poor reversibility upon N2 purge, which can be improved by exposing to light. This light-mediated CO2-responsiveness can be elucidated by the loss of aromaticity from initial photoexcitation and concurrent formation of a less reactive, antiaromatic excited state of relatively low CO2 binding affinity, and by subsequent relief of antiaromaticity that can enhance the CO2 removal. The finding is also checked by CO2 uptake-release experiments on the microgels, which enables both CO2 capture of high capacity and CO2 removal of good reversibility under a mild condition, allowing effective and reversible response to dilute CO2.
Accurate single-cell capture is a crucial step for single cell biological and chemical analysis. Conventional single-cell capturing often confront operational complexity, limited efficiency, cell damage, large scale but low accuracy, incompetence in the acquirement of nano-upgraded single-cell liquid. Flow cytometry has been widely used in large-scale single-cell detection, while precise single-cell isolation relies on both a precision operating platform and a microscope, which is not only extremely inefficient, but also not conducive to couple with modern analytical instruments. Herein, we develop a modular single-cell pipette (mSCP) microfluidic chip with high efficiency and strong applicability for accurate direct capture of single viable cell from cell suspensions into nanoliter droplets (30-1000 nL). The mSCP is used as a sampling platform for the detection of CdTe quantum dots in single cells with electrothermal atomic absorption spectrometry (ETAAS) for the first time. It also ensures precise single-cell sampling and detection by inductively coupled plasma mass spectrometry (ICP-MS).
Oximes derivatives have been vastly used in organic synthesis. In this review, C(sp3)−H bond functionalization of oximes derivatives via iminyl radical induced 1, 5−hydrogen atom transfer was discussed. According to the different type of products, this review was divided into three parts: (1) C(sp3)−H bond functionalization for C−C bond formation. (2) C(sp3)−H bond functionalization for C−N bond formation. (3) C(sp3)−H bond functionalization for C−S, C−F bond formation.
Considering the significant importance in both ecological and environmental fields, converting nitrogen oxide (NOx, especially NO) into value-added NH3 or harmless N2 lies in the core of research over the past decades. Exploring catalyst for related gas molecular activation and highly efficient reaction systems operated under low temperature or even mild conditions are the key issues. Enormous efforts have been devoted to NO removal by utilizing various driving forces, such as thermal, electrical or solar energy, which shine light on the way to achieve satisfying conversion efficiency. Herein, we will review the state-of-the-art catalysts for NO removal driven by the above-mentioned energies, including a comprehensive introduction and discussion on the pathway and mechanism of each reaction, and the recent achievements of catalysts on each aspect. Particularly, the progress of NO removal by environmentally friendly photocatalysis and electrocatalysis methods will be highlighted. The challenges and opportunities in the future research on the current topic will be discussed as well.
A facile and sustainable approach for the amination of benzothiazoles with KSeCN using iodine as the catalyst in water has been disclosed under transition-metal free conditions. The reaction proceeded smoothly to afford various primary 2-amino benzothiazoles in up to 96% yield. A series of control experiments were performed, suggesting a ring-opening mechanism was involved via a radical process. This protocol provides efficient synthesis of primary 2-aminobenzothiazoles
A novel and efficient electro-chemical initiated radical strategy was developed for the preparation of both N-substituted and N-unsubstituted 4-selanylisoquinolin-1(2H)-ones through selenylation of isoquinolin-1(2H)-ones with organodiselenides under chemical oxidant-, additive-free and ambient conditions.
A simple and efficient method for the synthesis of pyrazoles through a silicotungstic acid (H4SiW12O40)-catalyzed cyclization of epoxides/aldehydes and sulfonyl hydrazides has been developed. Various epoxides/aldehydes were smoothly reacted with sulfonyl hydrazides to furnish regioselectivity 3, 4-disubstituted 1H-pyrazoles. The application of such an earth-abundant, readily accessible, and nontoxic catalyst provides a green approach for the construction of 3, 4-disubstituted 1H-pyrazoles. A plausible reaction mechanism has been proposed on the basis of control experiments, GC-MS and DFT calculations.