Designing highly efficient photocatalyst for the valorization of CO_(2) is an ideal strategy to reduce greenhouse gas emissions and utilize solar energy.In this study,a S-scheme heterojunction photocatalyst is fabrica...Designing highly efficient photocatalyst for the valorization of CO_(2) is an ideal strategy to reduce greenhouse gas emissions and utilize solar energy.In this study,a S-scheme heterojunction photocatalyst is fabricated by solvothermal impregnation of ZnO on W_(18)O_(49) for photocatalytic CO_(2) N-formylation of aniline.The localized surface plasmon resonance effect of W_(18)O_(49) improves the absorption capacity for long-wave light significantly,and the hot electrons generated in W_(18)O_(49) with a high energy can migrate to the conduction band of ZnO and thus enhance the photocatalytic reduction ability.Meanwhile,the S-scheme heterojunction facilitates the separation of photoinduced charge carriers and preserves the redox ability of W_(18)O_(49)/ZnO composite photocatalyst.The conversion of aniline reaches 99.1%after 5 h reaction under visible light irradiation at room temperature with an N-formylaniline selectivity of 100%.A possible photocatalytic reaction mechanism is proposed.This study paves a promising way for the design of highly efficient photocatalyst and the sustainable utilization of CO_(2).展开更多
Some environmentally friendly catalysts such as HY and H β zeolites, various cation exchanged β zeolites, and some other solids have been used in the acylation reaction of ethylidenecyclohexane with acetic anhydride...Some environmentally friendly catalysts such as HY and H β zeolites, various cation exchanged β zeolites, and some other solids have been used in the acylation reaction of ethylidenecyclohexane with acetic anhydride at room temperature to synthesize 3 (1 cyclohexenyl) 2 butanone instead of conventional catalysts. The effect of the amount of HY zeolite used on the acylation reaction was investigated. The yield of the acylated product was 72% in the case of n (ethylidenecyclohexane)∶ n (acetic anhydride)∶ m (HY zeolite)=1 mmol∶10 mmol∶0 100 g, reaction temperature: 25 ℃, and reaction time:2 h. The regenerated HY zeolite showed almost the same catalytic activity as the fresh zeolite.展开更多
A redox‐neutral avenue to access isoquinolines has been realized by a Co（III）‐catalyzed C–H activa‐tion process. Starting from readily available N‐sulfinyl imine substrates and alkynes, the reaction occurred vi...A redox‐neutral avenue to access isoquinolines has been realized by a Co（III）‐catalyzed C–H activa‐tion process. Starting from readily available N‐sulfinyl imine substrates and alkynes, the reaction occurred via N–S cleavage with broad substrate scope and functional group compatibility in the presence of cost‐effective cobalt catalysts.展开更多
Accelerating the separation efficiency of photoexcited electron-hole pairs with the help of highly active co-catalysts has proven to be a promising approach for improving photocatalytic activity. Thus far, the most de...Accelerating the separation efficiency of photoexcited electron-hole pairs with the help of highly active co-catalysts has proven to be a promising approach for improving photocatalytic activity. Thus far, the most developed co-catalysts for semiconductor-based photocatalysis are inorganic materials;the employment of a specific organic molecule as a co-catalyst for photocatalytic hydrogen evolution and pollutant photodegradation is rare and still remains a challenging task. Herein, we report on the use of an organic molecule, oxamide (OA), as a novel co-catalyst to enhance electron- hole separation, photocatalytic H2 evolution, and dye degradation over TiO2 nanosheets. OA-modified TiO2 samples were prepared by a wet chemical route and demonstrated improved light absorption in the visible-light region and more efficient charge transport. The photocatalytic performance of H2 evolution from water splitting and rhodamine B (RhB) degradation for an optimal OA-modified TiO2 photocatalyst reached 2.37 mmol g^–1 h^–1 and 1.43 × 10^-2 min^-1, respectively, which were 2.4 and 3.8 times higher than those of pristine TiO2, respectively. A possible mechanism is proposed, in which the specific π-conjugated structure of OA is suggested to play a key role in the enhancement of the charge transfer and catalytic capability of TiO2. This work may provide advanced insight into the development of a variety of metal-free organic molecules as functional co-catalysts for improved solar-to-fuel conversion and environmental remediation.展开更多
文摘Designing highly efficient photocatalyst for the valorization of CO_(2) is an ideal strategy to reduce greenhouse gas emissions and utilize solar energy.In this study,a S-scheme heterojunction photocatalyst is fabricated by solvothermal impregnation of ZnO on W_(18)O_(49) for photocatalytic CO_(2) N-formylation of aniline.The localized surface plasmon resonance effect of W_(18)O_(49) improves the absorption capacity for long-wave light significantly,and the hot electrons generated in W_(18)O_(49) with a high energy can migrate to the conduction band of ZnO and thus enhance the photocatalytic reduction ability.Meanwhile,the S-scheme heterojunction facilitates the separation of photoinduced charge carriers and preserves the redox ability of W_(18)O_(49)/ZnO composite photocatalyst.The conversion of aniline reaches 99.1%after 5 h reaction under visible light irradiation at room temperature with an N-formylaniline selectivity of 100%.A possible photocatalytic reaction mechanism is proposed.This study paves a promising way for the design of highly efficient photocatalyst and the sustainable utilization of CO_(2).
文摘Some environmentally friendly catalysts such as HY and H β zeolites, various cation exchanged β zeolites, and some other solids have been used in the acylation reaction of ethylidenecyclohexane with acetic anhydride at room temperature to synthesize 3 (1 cyclohexenyl) 2 butanone instead of conventional catalysts. The effect of the amount of HY zeolite used on the acylation reaction was investigated. The yield of the acylated product was 72% in the case of n (ethylidenecyclohexane)∶ n (acetic anhydride)∶ m (HY zeolite)=1 mmol∶10 mmol∶0 100 g, reaction temperature: 25 ℃, and reaction time:2 h. The regenerated HY zeolite showed almost the same catalytic activity as the fresh zeolite.
基金supported by the Dalian Institute of Chemical Physics,Chinese Academy of Sciencesthe National Natural Science Foundation of China (21272231)~~
文摘A redox‐neutral avenue to access isoquinolines has been realized by a Co（III）‐catalyzed C–H activa‐tion process. Starting from readily available N‐sulfinyl imine substrates and alkynes, the reaction occurred via N–S cleavage with broad substrate scope and functional group compatibility in the presence of cost‐effective cobalt catalysts.
基金supported by the National Natural Science Foundation of China(51672113,51602132)the Six Talent Peaks Project in Jiangsu Province(2015-XCL-026)+2 种基金the Natural Science Foundation of Jiangsu Province(BK20171299)the Training Project of Jiangsu University for Young Cadre Teachers(5521220009)the Youth Research Project of Jiangsu Health and Family Planning Commission in 2016(Q201609)~~
文摘Accelerating the separation efficiency of photoexcited electron-hole pairs with the help of highly active co-catalysts has proven to be a promising approach for improving photocatalytic activity. Thus far, the most developed co-catalysts for semiconductor-based photocatalysis are inorganic materials;the employment of a specific organic molecule as a co-catalyst for photocatalytic hydrogen evolution and pollutant photodegradation is rare and still remains a challenging task. Herein, we report on the use of an organic molecule, oxamide (OA), as a novel co-catalyst to enhance electron- hole separation, photocatalytic H2 evolution, and dye degradation over TiO2 nanosheets. OA-modified TiO2 samples were prepared by a wet chemical route and demonstrated improved light absorption in the visible-light region and more efficient charge transport. The photocatalytic performance of H2 evolution from water splitting and rhodamine B (RhB) degradation for an optimal OA-modified TiO2 photocatalyst reached 2.37 mmol g^–1 h^–1 and 1.43 × 10^-2 min^-1, respectively, which were 2.4 and 3.8 times higher than those of pristine TiO2, respectively. A possible mechanism is proposed, in which the specific π-conjugated structure of OA is suggested to play a key role in the enhancement of the charge transfer and catalytic capability of TiO2. This work may provide advanced insight into the development of a variety of metal-free organic molecules as functional co-catalysts for improved solar-to-fuel conversion and environmental remediation.
