Graphite carbon nitride has many excellent properties as a two-dimensional semiconductor material so that it has a wide application prospect in the field of photocatalysis.However,the traditional problems such as high...Graphite carbon nitride has many excellent properties as a two-dimensional semiconductor material so that it has a wide application prospect in the field of photocatalysis.However,the traditional problems such as high recombination rate of photogenerated carriers limit its application.In this work,we introduce nitrogen deficiency into g-C_(3)N_(4)to solve this problem a simple and safe in-situ reduction method.g-C_(3)N_(4)/CaCO_(3)was obtained by a simple and safe one-step calcination method with industrial-grade micron particles CaCO_(3).Cyano group modification was in-situ reduced during the thermal polymerization process,which would change the internal electronic structure of g-C_(3)N_(4).The successful combination of g-C_(3)N_(4)and CaCO_(3)and the introduction of cyanide have been proved by Fourier transform infrared spectroscopy and X-ray photoelectron spectrometer.The formation of the cyano group,an electron-absorbing group,promotes the effective separation of photogenic electron hole pairs and inhibits the recombination of photogenic carriers.These advantages result in the generation of more·O_(2)-and1O_(2)in the catalytic system,which increases the photocatalytic efficiency of nicotine degradation by ten times.Furthermore,the degradation process of nicotine has been studied in this work to provide a basis for the degradation of nicotine organic pollutants in the air.展开更多
The dual incorporation of two important functional groups—trifluoromethyl and cyano moieties into one heterocyclic core in a single-step reaction represents an appealing but largely unaddressed synthetic challenge.He...The dual incorporation of two important functional groups—trifluoromethyl and cyano moieties into one heterocyclic core in a single-step reaction represents an appealing but largely unaddressed synthetic challenge.Here we demonstrate that a silver-catalyzed[3+2]cycloaddition reaction of dicyanoalkenes with trifluorodiazoethane(CF_(3)CHN2)could render a facile construction of a unique category of pyrazoles that are simultaneously adorned by trifluoromethyl and cyano groups.Changing the location pattern of the cyano group in starting dicyanoalkene material allows regiodivergent access to two series of previously elusive trifluoromethyl cyanopyrazoles with an exquisite level of regiocontrol.Thus,this method could be applied in the preparation of cyano-analogues of CF_(3)-containing drugs(Celecoxib)and agrochemicals(Penthiopyrad and Fluazolate).Notably,several cyano-analogues of Celecoxib demonstrate enhanced inhibitory activity towards cyclooxygenase-2(COX-2),thereby laying a good foundation for developing new lead-based antiinflammatory agents.展开更多
The existence of defects in perovskite films is a major obstacle that prevents perovskite solar cells (PSCs) from high efficiency and long-term stability. A variety of additives have been introduced into perovskite fi...The existence of defects in perovskite films is a major obstacle that prevents perovskite solar cells (PSCs) from high efficiency and long-term stability. A variety of additives have been introduced into perovskite films for reducing the number of defects. Lewis base-based additive engineering has been considered as an effective way to eliminate defects, especially the defects caused by the uncoordinated Pb^(2+). In this work, for the first time, a bilateral cyano molecule (succinonitrile, SN) which is a commonly used plasticizer in solid electrolyte of solid-state lithium batteries was selected as an additive to modify organic–inorganic hybrid perovskite films in PSCs. SN is featured with two cyano groups (–C≡N) distributing at both terminals of the carbon chain, providing two cross-linking points to interact with perovskites crystals via coordinating with uncoordinated Pb2+ and forming hydrogen bonds with –NH2 groups in perovskite. It was found that the addition of SN into perovskite precursor solution could effectively reduce defects, particularly inhibit the appearance of Pb0 and thus suppress trap-assisted nonradiative charge carrier recombination. As a result, the efficiency of CH_(3)NH_(3)PbI_(3)(Cl) (MAPbI_(3)(Cl))-based PSCs was improved from 18.4% to 20._(3)% with enhanced long-term stability at N2 and humid air atmosphere. This work provides a facile and effective strategy to enhance the PCE and stability of PSCs simultaneously, facilitating the commercialization of PSCs.展开更多
基金supported by the National Natural Science Foundation of China (No.51703201)。
文摘Graphite carbon nitride has many excellent properties as a two-dimensional semiconductor material so that it has a wide application prospect in the field of photocatalysis.However,the traditional problems such as high recombination rate of photogenerated carriers limit its application.In this work,we introduce nitrogen deficiency into g-C_(3)N_(4)to solve this problem a simple and safe in-situ reduction method.g-C_(3)N_(4)/CaCO_(3)was obtained by a simple and safe one-step calcination method with industrial-grade micron particles CaCO_(3).Cyano group modification was in-situ reduced during the thermal polymerization process,which would change the internal electronic structure of g-C_(3)N_(4).The successful combination of g-C_(3)N_(4)and CaCO_(3)and the introduction of cyanide have been proved by Fourier transform infrared spectroscopy and X-ray photoelectron spectrometer.The formation of the cyano group,an electron-absorbing group,promotes the effective separation of photogenic electron hole pairs and inhibits the recombination of photogenic carriers.These advantages result in the generation of more·O_(2)-and1O_(2)in the catalytic system,which increases the photocatalytic efficiency of nicotine degradation by ten times.Furthermore,the degradation process of nicotine has been studied in this work to provide a basis for the degradation of nicotine organic pollutants in the air.
基金This work is supported by the National Natural Science Foundation of China(grant nos.92156025,21901181,and 21961142015)the National Key Research and Development Program of China(grant nos.2019YFA0905100 and 2021YFF0701700)Tianjin Municipal Science and Technology Commission(grant no.19JCQNJC04700).
文摘The dual incorporation of two important functional groups—trifluoromethyl and cyano moieties into one heterocyclic core in a single-step reaction represents an appealing but largely unaddressed synthetic challenge.Here we demonstrate that a silver-catalyzed[3+2]cycloaddition reaction of dicyanoalkenes with trifluorodiazoethane(CF_(3)CHN2)could render a facile construction of a unique category of pyrazoles that are simultaneously adorned by trifluoromethyl and cyano groups.Changing the location pattern of the cyano group in starting dicyanoalkene material allows regiodivergent access to two series of previously elusive trifluoromethyl cyanopyrazoles with an exquisite level of regiocontrol.Thus,this method could be applied in the preparation of cyano-analogues of CF_(3)-containing drugs(Celecoxib)and agrochemicals(Penthiopyrad and Fluazolate).Notably,several cyano-analogues of Celecoxib demonstrate enhanced inhibitory activity towards cyclooxygenase-2(COX-2),thereby laying a good foundation for developing new lead-based antiinflammatory agents.
基金This work was supported by the Australian Research Council Discovery Projects(DPI 50104365 and DPI 60104835)the National Natural Science Foundation of China(No.21908106 and 21878158)+2 种基金the Jiangsu Natural Science Foundation(No.BK20190682)the Program forjiangsu Specially-Appointed Professors,the Funding from State Key Laboratory of Materials-Oriented Chemical Engineering(No.ZK201808)a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘The existence of defects in perovskite films is a major obstacle that prevents perovskite solar cells (PSCs) from high efficiency and long-term stability. A variety of additives have been introduced into perovskite films for reducing the number of defects. Lewis base-based additive engineering has been considered as an effective way to eliminate defects, especially the defects caused by the uncoordinated Pb^(2+). In this work, for the first time, a bilateral cyano molecule (succinonitrile, SN) which is a commonly used plasticizer in solid electrolyte of solid-state lithium batteries was selected as an additive to modify organic–inorganic hybrid perovskite films in PSCs. SN is featured with two cyano groups (–C≡N) distributing at both terminals of the carbon chain, providing two cross-linking points to interact with perovskites crystals via coordinating with uncoordinated Pb2+ and forming hydrogen bonds with –NH2 groups in perovskite. It was found that the addition of SN into perovskite precursor solution could effectively reduce defects, particularly inhibit the appearance of Pb0 and thus suppress trap-assisted nonradiative charge carrier recombination. As a result, the efficiency of CH_(3)NH_(3)PbI_(3)(Cl) (MAPbI_(3)(Cl))-based PSCs was improved from 18.4% to 20._(3)% with enhanced long-term stability at N2 and humid air atmosphere. This work provides a facile and effective strategy to enhance the PCE and stability of PSCs simultaneously, facilitating the commercialization of PSCs.
