The broadband light-absorption ability of carbon dots (CDs) has inspired their application in photocatalysis, however this has been impeded by poor electron transfer inside the CDs. Herein, we report the preparation of Cu-N-doped CDs (Cu-CDs) and investigate both the doping-promoted electron transfer and the performance of the CDs in photooxidation reactions. The Cu-N doping was achieved through a one-step pyrolytic synthesis of CDs with Na2 [Cu(EDTA)] as precursor. As confirmed by ESR, FTIR, and X-ray photoelectron spectroscopies, the Cu species chelates with the carbon matrix through Cu-N complexes. As a result of the Cu-N doping, the electron-accepting and -donating abilities were enhanced 2.5 and 1.5 times, and the electric conductivity was also increased to 171.8 μs cm(-1) . As a result of these enhanced properties, the photocatalytic efficiency of CDs in the photooxidation reaction of 1,4-dihydro-2,6-dimethylpyridine-3,5-dicarboxylate is improved 3.5-fold after CD doping.

The outstanding visible light response of carbon nitride has aroused intense expectations regarding its photocatalysis, but it is impeded by the inevitable defects. Here, we report on a facile melamine-based defect-remedying strategy and resultant carbon nitride high-performance photocatalysts (R-C 3 N 4 ). Melamine with amino groups and a triazine structure was selected as a "little patch" to passivate and remedy various defects inside carbon nitride. Such a remedying effect has been comprehensively proven by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) analyses, and the ninhydrin test. In addition, their effects on photocatalysis were also individually confirmed by chemical methods, including cyano reduction reactions and deamination reactions. Furthermore, melamine remediation can result in g-C 3 N 4 /mpg-C 3 N 4 junctions, which also favors electron transfer and charge separation during the photocatalytic reaction. In order to explore its broader applications, R-C 3 N 4 was used as a photocatalyst for the photooxidation reaction of 1,4dihydro-2,6-dimethylpyridine-3,5-dicarboxylate (1,4-DHP) and simultaneous H 2 evolution. The conversion rates of 1,4-DHP and H 2 production catalyzed by R-C 3 N 4 were enhanced 2 and 6.5 times, respectively. This rational design is beneficial for the conversion of 1,4-DHP during the preparation of bioactive compounds and clean hydrogen production at the same time.

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Self-propelled metal–organic framework (MOF)-based Janus micromotors that propel autonomously in hydrogen peroxide and display effective remediation of contaminated water is presented in this work.

We study the hadron yield correlation in the combination models in high-energy heavy-ion collisions. We derive the relationship between the average yields of different hadrons produced in the combination of a system consisting of equal numbers of quarks and antiquarks. We present the results for the directly produced hadrons as well as those for the final hadrons including the strong and electromagnetic decay contributions. We also study the net quark influence by considering the case when the number of quarks is larger than that of antiquarks. We make comparison with the data wherever possible.