Regulating Organic Modifiers on Metal-Based Catalysts for Enhanced Electrocatalytic CO Reduction.

Electrochemical CO reduction reaction (CORR) has been proved as a promising pathway for valuable chemical production and sustainable carbon cycling. Various regulatory strategies have been explored to boost CORR performance. Among these, metal-based electrocatalytic CORR systems regulated by organic modifiers have been shown to play a pivotal role in regulating the complex catalytic processes.

The impact of nitrogen doping and reduced-niobium self-doping on the photocatalytic activity of ultra-thin NbO nanosheets.

Nitrogen doping via high-temperature ammonization is a frequently used strategy to extend the light harvesting capacity of wide-bandgap catalysts in the visible region. Under such a reductive atmosphere, the reduction of transition metals is supposed to occur, however, this has not been thoroughly studied yet. Here, by combining chemically-controlled doping and subsequent liquid exfoliation, ultra-thin [NbO] nanosheets with separate N doping, reduced-Nb doping and N/reduced-Nb codoping were fabricated for comparative studies on the doping effect for photocatalytic hydrogen evolution.

A Multiple Structure-Design Strategy towards Ultrathin Niobate Perovskite Nanosheets with Thickness-Dependent Photocatalytic Hydrogen-Evolution Performance.

Hydrogen production by catalytic water splitting using sunlight holds great promise for clean and sustainable energy source. Despite the efforts made in the past decades, challenges still exist in pursuing solid catalysts with light-harvesting capacity, large surface areas and efficient utilities of the photogenerated carrier, at the same time. Here, a multiple structure design strategy leading to highly enhanced photocatalytic performance on hydrogen production from water splitting in Dion-Jacobson perovskites KCa Na Nb O is described.

Fluorescent N-Doped Carbon Dots as in Vitro and in Vivo Nanothermometer.

The fluorescent N-doped carbon dots (N-CDs) obtained from C3N4 emit strong blue fluorescence, which is stable with different ionic strengths and time. The fluorescence intensity of N-CDs decreases with the temperature increasing, while it can recover to the initial one with the temperature decreasing. It is an accurate linear response of fluorescence intensity to temperature, which may be attributed to the synergistic effect of abundant oxygen-containing functional groups and hydrogen bonds.

Visible-Light-Induced Effects of Au Nanoparticle on Laccase Catalytic Activity.

A deep understanding of the interaction between the nanoparticle and enzyme is important for biocatalyst design. Here, we report the in situ synthesis of laccase-Au NP (laccase-Au) hybrids and its catalytic activity modulation by visible light. In the present hybrid system, the activity of laccase was significantly improved (increased by 91.

Non-metal single/dual doped carbon quantum dots: a general flame synthetic method and electro-catalytic properties.

A combustion flame method is developed for the convenient and scalable fabrication of single- and dual-doped carbon quantum dots (CQDs) (N-CQDs, B-CQDs, P-CQDs, and S-CQDs and dual-doped B,N-CQDs, P,N-CQDs, and S,N-CQDs), and the doping contents can be easily adjusted by simply changing the concentrations of precursors in ethanol. These single/dual-doped CQDs, especially B,N-CQDs, show high catalytic activities for the oxygen reduction reaction.

Size-dependent and real-time effect of SiO nanoparticles on a single living HeLa Cell's membrane permeability.

In this study, we provide the quantitative data on the membrane permeability of a HeLa cell in the presence of different sizes of SiO nanoparticles (NPs, 50, 100 and 200 nm). SiO NPs have low cytotoxicity, but 50 and 100 nm SiO NPs can increase the cell membrane permeability (a reversible effect) by 12.5% (0.

Convenient and sensitive detection of norfloxacin with fluorescent carbon dots.

Carbon dots (CDs) were synthesized by refluxing glucose, as efficient fluorescence probes, which show convenient and sensitive detection of norfloxacin (NOR) over a wide concentration range. It is worth noting that because of the hydrogen bond interactions between the CDs and NOR, the fluorescence intensity of CDs was remarkably enhanced in the presence of NOR, which indicates that CDs are capable of rapid, stable and sensitive determination of NOR. Compared with high-performance liquid chromatography, the fluorescence enhancement method is considerably simpler and faster, and will pave a new way for the determination of NOR.

One-step catalase controllable degradation of CN for N-doped carbon dot green fabrication and their bioimaging applications.

Water-soluble fluorescent N-doped carbon dots (N-C dots) obtained by enzyme catalyzed degradation of CN show high stability, good biocompatibility, and can be promising candidates for bioimaging.

Carbon dots for photoswitching enzyme catalytic activity.

Enzyme engineering for improved catalysis has wide implications. Here, we report the modulation of enzyme (porcine pancreatic lipase, PPL) catalytic activity in the presence of carbon quantum dots (CQDs) by visible light. Upon visible light irradiation, the activity of PPL/CQDs increased to 10% higher than that of free PPL, whereas without a light source, the activity of PPL/CQDs decreased to 30% lower than that of free PPL.

High-bright fluorescent carbon dots and their application in selective nucleoli staining.

Fluorescent carbon dots (FCDs) were synthesized by refluxing polyethylene glycol, which can emit bright and different fluorescent colours under various wavelengths as well as show stable fluorescence properties with different ionic strength, temperature and time. These FCDs exhibit good biocompatibility and very low toxicity for HeLa cells. Notably, these FCDs, as an efficient live cell fluorescence imaging probe, can selectively stain nucleoli, and the effect is similar to some commercially available dyes (such as Hoechst).

[Diagnosis boundary values of metabolic syndrome obesity index for children and adolescents].

Objective: To determine the distribution characteristics of waist circumference (WC), waist height ratio (WHtR) of 6-18 years olds in Guangzhou, and to put forward the WC and WHtR appropriate boundary values for 6-18 years olds on the basis of cardiovascular disease (CVD) risk factor assessment.

Methods: We analyzed the height, weight, WC and its metabolic indication data (blood pressure, fasting blood glucose, and blood lipids) of 15 000 children in Guangzhou, aged 6-18, with the receiver-operating characteristic curve (ROC), and explored the best value point of WC and WHtR for the prediction of cardiovascular diseases.

Results: When the WC percent reached P85, and WHtR reached 0.

Au nanoparticles in carbon nanotubes with high photocatalytic activity for hydrocarbon selective oxidation.

High-efficiency and high-selectivity catalytic oxidation of alkanes under mild conditions with air is a major aim of current catalytic chemistry and chemical production. Despite extensive development efforts on new catalysts for cyclohexane oxidation, current commercial processes still suffer from low conversion, poor selectivity, and excessive production of waste. Here, we present the design and synthesis of gold nanoparticle/carbon nanotube (CNT) composites for high-efficiency and high-selectivity photocatalyst systems for the green oxidation of cyclohexane.

Adsorption dominant catalytic activity of a carbon dots stabilized gold nanoparticles system.

Carbon dots (CDs) with abundant functional groups (-OH, -COOH, C=O) on their surface were specially designed to enhance the adsorption capacity and the catalytic activity of gold nanoparticles (AuNPs). The CDs stabilized gold nanoparticles (AuNPs-CDs) were greenly synthesized by a one-step reduction of HAuCl4 with CDs which were used as both the reductant and the stabilizer under visible light irradiation. The resulting AuNPs-CDs exhibit a high catalytic activity towards the reduction of 4-nitrophenol, with a good linear correlation of ln(C(i)/C0) versus time and a kinetic rate constant about 0.

Quantitative and real-time effects of carbon quantum dots on single living HeLa cell membrane permeability.

The interaction between carbon quantum dots (CQDs) and a single living cell was explored in real time. Here, we provide the quantitative data on the permeability of the HeLa cell membrane in the presence of CQDs with different surface functional groups (CQDs terminated with -OH/-COOH (CQD-OH), -PEG (CQD-PEG), and -NH2 (CQD-NH2)). Although these CQDs have very low toxicity towards HeLa cells, they still increase the cell membrane permeability by 8%, 13%, and 19% for CQD-PEG, CQD-OH, and CQD-NH2, respectively, and this kind of permeability was irreversible.

Carbon quantum dots with photo-generated proton property as efficient visible light controlled acid catalyst.

Developing light-driven acid catalyst will be very meaningful for the controlled-acid catalytic processes towards a green chemical industry. Here, based on scanning electrochemical microscopy (SECM) and ΔpH testing, we demonstrate that the 5-10 nm carbon quantum dots (CQDs) synthesized by electrochemical ablation of graphite have strong light-induced proton properties under visible light in solution, which can be used as an acid catalyst. The 5-10 nm CQDs' catalytic activity is strongly dependent on the illumination intensity and the temperature of the reaction system.