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Summary Highly crystalline and emissive carbon dots (CDs) are firstly synthesized via an ionothermal method in organic solvents. In contrast to well-established approaches, ZnCl2 is utilized as the pyrolysis-promoting agent to prepare emissive CDs with tunable wavelengths, directly by carbonization from different O and N precursors under a mild reaction condition at 210°C. More than 50% synthetic yield and 39% photoluminescent quantum yield (blue CD) are obtained. XAFS measurements, in conjunction with TEM, HAADF-STEM, UPS, and ESR analyses, allow us to obtain energy diagram configuration and confirm the luminescent nature of these hard-core structured CDs. Importantly, the resulting CDs exhibit excellent capability to photogenerate superoxide radical anion (O2⋅–), which can be exemplified by both photodynamic therapy and photooxidative cyclization synthesis of tetrahydroquinolines. Representative pharmaceutical mifepristone can be derivatized in 90% yield within 10 min of irradiation of the CDs in an elegant flow reactor.

Efficient borylation reaction of diazonium salts in water is realized for the first time by using easily prepared, highly emissive and crystalline carbon dots. Electron-donating and electron-withdrawing groups on diazonium salts were well tolerated with moderate to good conversion efficiency. Compared with widely used metal complexes, organic dyes and quantum dots, the approach presented herein uses carbon dots, which are nontoxic and possess good biological and medicinal compatibility and high reactivity. Therefore, this approach presents a new prospective use for carbon dots in green chemistry.

In this paper, catalysts of (NH4)4SiW12O40 supported on polyvinylidene fluoride(PVDF) thin films were prepared and characterized by IR and SEM.In addition,sunlight as the light source and simulation of dyes effluent (malachite green) as the research object, through the orthogonal experiments studied the factors that influence catalyst photocatalytic degradation effects,such as the amount of catalyst, pH, the amount of hydrogen peroxide . The results show that the degradation of malachite green of the heteropoly acid catalyst immobilized by membrane is best under the conditions of visible and achieve high degradation rate( 90% ). Also , the catalytic effect is also related with the oxidant dosage and the acidity. The catalyst is energy saving, easy recovery and has widest foreground.