Theory and Method of Selecting Green Reductants of Ce(Ⅳ)

From atom economy of green chemistry,two principles of selecting reductant were gotten: the smaller consumption of reductant material quantity per Mole-electron,and the lighter load on environment. On the basis of these two principles,experimental research was done on organic compounds. Alcohol,ketone,amine,ester,acid,and alcohol,ketone,amine were selected to act as green reductants,whose optimal process parameters were obtained. Compared with the traditional method,researched method decreases not only the amount of reductants by about 90%,but also the amount of acid medium and solid waste,where the by-products are carbon dioxide and water. The acid medium is recycled.

Synthesis of [2,2’]Bifuranyl-5,5’-dicarboxylic Acid Esters Wd Reductive Homocoupling of 5-Bromofuran-2-carboxylates Using Alcohols as Reductants

Herein,we describe an environmentally benign and cost.efective protocol for the synthesis of valuable bifuranyl dicarboylates,starting with a-bromination of readily accessible furan-2-carboylates by LiBr and K_(2)S_(2)O_(8).Furthermore,the bromination intermediate product 5-bromofuran-2-carboxylates were then conducted in a palladium-catalyzed reductive homocoupling reactions in the pres-ence of alcohols to afford bifuranyl dicarboxylates.One of the final products in this protocol,[2,2']bifuran-5,5'-dicarboxylic acid es-ters,are essential monomers of poly(ethylene bifuranoate),which can be served as an green and versatile alternative polymer for traditional poly(ethylene terephthalate)that is currently common in technical plastics.

Near-UV light assisted green reduction of graphene oxide films through l-ascorbic acid

Recent studies have highlighted the effects of various stimuli on the chemical reduction of graphene oxide(GO)through green reductant L-ascorbic acid(L-AA);however,the combination of near ultraviolet(NUV)light to increase the reduction rate has yet to be thoroughly explored.In this study,drop-casted GO films were subjected to chemical reduction through L-AA with various levels of exposure under 405 nm NUV radiation.The structure and uniformity of GO stackings that form the film were characterized through scanning electron microscopy(SEM)and wide-angle x-ray scattering(WAXS).Additionally,WAXS was used to track the removal of oxygen-containing functional groups along with Fourier-transform infrared(FT-IR)spectroscopy and x-ray photoelectron spectroscopy(XPS)as a function of L-AA and NUV light exposure times.XPS results demonstrated that the interaction between L-AA and NUV exposure has a significant effect on the reduction of films.Furthermore,the results that yielded the highest reduction(C-C bond concentration of 60.7%)were the longest L-AA and NUV light exposure times(48 hours and 3 hours,respectively).This report provides a study on the effects of NUV on the green reduction of GO films through L-AA with potential application in solar energy and chemical sensing applications.

Facile synthesis of graphene via reduction of graphene oxide by artemisinin in ethanol

The preparation of reduced graphene oxide(RGO)by chemical reduction of graphene oxide(GO)usually involves highly toxic reducing agents which are harmful to the environment and human health.In this paper,a mediated facile and relative green approach for the preparation of RGO in ethanol using artemisinin as a reducing agent is reported for the first time.The morphology and de-oxidation efficiency of the obtained RGO were characterized by transmission electron microscope(TEM),atomic force microscope(AFM),and X-ray photoelectron spectroscopy(XPS).The results showed that artemisinin can effectively reduce GO into few-layered RGO with a high carbon to oxygen ratio(11.7).The mechanism for elimination of oxygen-containing functional groups decorated on GO nanosheets by artemisinin was proposed.The important features of relatively environmentally friendly and facile operation procedures endow this approach with great promise in the mass production of RGO and various graphene-based materials,especially for biomaterials.

A Fast and Highly Efficient Protocol for Reductive Amination of Aromatic Aldehydes Using NaBH4 and Isoxazole Amines in an Ionic Liquid Medium

Reductive amination of aromatic aldehydes using NaBH4 and isoxazole amines is carried out in a Bronsted acidic ionic liquid 1 -methylimidazolium tetrafluoroborate [（HMIm）BF4]. The ionic liquid plays dual roles of solvent as well as catalyst for the efficixcellent yields without any undesired side product formation. The newly synthesized compoundsent transformation of aromatic aldehydes to heterocyclic substituted amines in e （3, 6 and 7） were characterized by IR, 1H NMR and mass spectral techniques.

Selective electroreduction of carbon dioxide to formic acid on electrodeposited SnO_2@N-doped porous carbon catalysts

Electrocatalytic reduction of CO_2 is a promising route for energy storage and utilization. Herein we synthesized SnO_2 nanosheets and supported them on N-doped porous carbon (N-PC) by electrodeposition for the first time. The SnO_2 and N-PC in the SnO_2@N-PC composites had exellent synergistic effect for electrocatalytic reduction of CO_2 to HCOOH. The Faradaic efficiency of HCOOH could be as high as 94.1% with a current density of 28.4 mA cm-2 in ionic liquid-MeCN system. The reaction mechanism was proposed on the basis of some control experiments. This work opens a new way to prepare composite electrode for electrochemical reduction of CO_2.