No abstract

Robust and highly active photocatalysts, CdS@MoS, for hydrogen evolution were successfully fabricated by one-step growth of oxygen-incorporated defect-rich MoS ultrathin nanosheets on the surfaces of CdS with irregular fissures. Under optimized experimental conditions, the CdS@MoS displayed a quantum yield of ∼24.2% at 420 nm and the maximum H generation rate of ∼17203.7 umol/g/h using NaS-NaSO as sacrificial agents (λ ≥ 420 nm), which is ∼47.3 and 14.7 times higher than CdS (∼363.8 μmol/g/h) and 3 wt % Pt/CdS (∼1173.2 μmol/g/h), respectively, and far exceeds all previous hydrogen evolution reaction photocatalysts with MoS as co-catalysts using NaS-NaSO as sacrificial agents. Large volumes of hydrogen bubbles were generated within only 2 s as the photocatalysis started, as demonstrated by the photocatalytic video. The high hydrogen evolution activity is attributed to several merits: (1) the intimate heterojunctions formed between the MoS and CdS can effectively enhance the charge transfer ability and retard the recombination of electron-hole pairs; and (2) the defects in the MoS provide additional active S atoms on the exposed edge sites, and the incorporation of O reduces the energy barrier for H evolution and increases the electric conductivity of the MoS. Considering its low cost and high efficiency, this highly efficient hybrid photocatalysts would have great potential in energy-generation and environment-restoration fields.

BackgroundSelenium is an important trace element for human health. Although numerous epidemiological and interventional studies have examined the association between selenium and diabetes, their findings have been inconclusive. Moreover, no research has specifically focused on the association between dietary selenium and diabetes in the Asian population. The objective of this study was to evaluate the relationship between dietary selenium and diabetes in middle-aged and elderly Chinese adults.MethodsA cross-sectional study including 5,423 subjects was carried out. The basic characteristics, biochemical test results, and dietary intake were collected from each subject for analysis. The adjusted odds ratio (OR) and the corresponding 95% confidence interval (CI) were used to determine the relationship between dietary selenium intake and diabetes through logistic regression.ResultsThe prevalence of diabetes in the study population was 9.7%, and the average level of dietary selenium intake was 43.51 μg/day. The multivariate adjusted OR was 1.52 (95% CI: 1.01 to 2.28, P = 0.04) for the highest quartile of dietary selenium intake in comparison with the lowest quartile. There was a significant positive association between dietary selenium intake and diabetes (P for trend = 0.03).ConclusionThere was a significant positive correlation between dietary selenium intake and the prevalence of diabetes.

No abstract

The development of effective approaches for the preparation of 0D quantum dots (QDs)/2D nanosheets (NSs) heterostructures, which have been proven to be favorable for heterogeneous catalysis, is highly desirable but remains a great challenge. Herein, 0D metal oxide nanocrystals-2D ultrathin g-C N nanosheets (Co O /CNNS) heterostructures are synthesized via a facile chemical reaction, followed by annealing in air. Ultrafine Co O QDs (≈2.2-3.2 nm) are uniformly and tightly attached on the surface of g-C N nanosheets. Detailed characterization reveals that the specially designed unique 0D/2D structure is critical to the high photocatalytic performance for the degradation of tetracycline (TC) via peroxymonosulfate (PMS) activation. The optimal catalyst, namely, Co O /CNNS-1100, exhibits excellent performance and ≈98.7% TC can be degraded under visible light irradiation. Moreover, TC degradation is almost completely insusceptible to several real water samples. Meanwhile, other dye pollutants can also be efficiently degraded by the Co O /CNNS-1100/PMS/vis system. The quenching tests display that that the h , ∙OH, O , and SO are responsible for TC removal. The improved photocatalytic performance can be attributed to the synergistic effect of the photocatalytic- and chemical-processes in the PMS activation. This work gives an insight into the development of multifunctional 0D/2D nanocomposites for further potential applications which are not limited to environmental purification.