Converting sustainable solar energy into hydrogen energy over semiconductor-based photocatalytic materials provides an alternative to fossil fuel consumption.However,efficient photocatalytic splitting of water to real...Converting sustainable solar energy into hydrogen energy over semiconductor-based photocatalytic materials provides an alternative to fossil fuel consumption.However,efficient photocatalytic splitting of water to realize carbon-free hydrogen production remains a challenge.Heterojunction photocatalysts with well-defined dimensionality and perfectly matched interfaces are promising for achieving highly efficient solar-to-hydrogen conversion.Herein,we report the fabrication of a novel type of protonated graphitic carbon nitride(PCN)/Ti3C2 MXene heterojunctions with strong interfacial interactions.As expected,the two-dimensional(2D)PCN/2D Ti3C2 MXene interface heterojunction achieves a highly improved hydrogen evolution rate(2181μmol∙g‒1)in comparison with bulk g-C3N4(393μmol∙g‒1)and protonated g-C3N4(816μmol∙g‒1).The charge-regulated surfaces of PCN and the accelerated charge transport at the face-to-face 2D/2D Schottky heterojunction interface are the major contributors to the excellent hydrogen evolution performance of the composite photocatalyst.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
Solar-powered photocatalytic hydrogen production from water using semiconductors provides an eco-friendly and promising approach for converting solar energy into hydrogen fuel.Bulk semiconductors generally suffer from...Solar-powered photocatalytic hydrogen production from water using semiconductors provides an eco-friendly and promising approach for converting solar energy into hydrogen fuel.Bulk semiconductors generally suffer from certain limitations,such as poor visible-light utilization,rapid recombination of charge carriers,and low catalytic capability.The key challenge is to develop visible-light-driven heterojunction photocatalysts that are stable and highly active during the water splitting process.Here,we demonstrate the integration of one-dimensional(1D)Cd S nanorods with two-dimensional(2D)1 T-phase dominated WS_(2) nanosheets for constructing mixed-dimensional heterojunctions for the photocatalytic hydrogen evolution reaction(HER).The resulting 1D CdS/2D WS_(2) nanoheterojunction exhibited an ultrahigh hydrogen-evolution activity of~70 mmol·g^(-1)·h^(-1) that was visible to the naked eye,as well as long-term stability under visible light illumination.The results reveal that the synergy of hybrid nanoarchitectures and intimate interfacial contact between the 1D Cd S nanorods and 1T-phase dominated 2D WS_(2) nanosheets facilitates charge carrier transport,which is beneficial for achieving superior hydrogen evolution.展开更多
The ethanol oxidation reaction is a significant anodic reaction for direct alcohol fuel cells.The most commonly used catalysts for this reaction are Pt‐based materials;however,Pt‐based electrocatalysts cause carbon ...The ethanol oxidation reaction is a significant anodic reaction for direct alcohol fuel cells.The most commonly used catalysts for this reaction are Pt‐based materials;however,Pt‐based electrocatalysts cause carbon monoxide poisoning with intermediates before the complete transformation of alcohol to CO_(2).Herein,we present hierarchical AgAu bimetallic nanoarchitectures for ethanol electrooxidation,which were fabricated via a partial galvanic reduction reaction between Ag and HAuCl_(4).The ethanol electrooxidation performance of the optimal AgAu nanohybrid was increased to 1834 mA mg^(‒1),which is almost 10 times higher than that of the pristine Au catalyst(190 mA mg^(‒1))in alkaline solutions.This was achieved by introducing Ag into the Au catalyst and controlling the time of the replacement reaction.The heterostructure also presents a higher current density than that of commercial Pt/C(1574 mA mg^(‒1)).Density functional theory calculations revealed that the enhanced activity and stability may stem from unavoidable defects on the surface of the integrated AgAu nanoarchitectures.Ethanol oxidation reactions over these defects are more energetically favorable,which facilitates the oxidative removal of carbonaceous poison and boosts the combination with radicals on adjacent Au active sites.展开更多
Multi-drug delivery focuses on different signaling pathways in cancer cells and has synergistic antiproliferative effects.In this manuscript,we developed folic acid(FA)-conjugated polymeric multi-drug nanoparticles(FA...Multi-drug delivery focuses on different signaling pathways in cancer cells and has synergistic antiproliferative effects.In this manuscript,we developed folic acid(FA)-conjugated polymeric multi-drug nanoparticles(FA-PMDNPs)consisting of poly-L-lysine(PLL)and poly glutamic-conjugated PTX/GEM(PGA-PTX and PGA-GEM)for FA receptor-targeted synergistic breast cancer therapy.The carboxyl-rich structure of PGA provided plenty reaction sites and negative charge for drug loading.Transmission electron microscopy(TEM)results showed that FA-PMDNPs had uniform particle size and spherical morphology.The hemolysis study proved that FA-PMDNPs had good biocompatibility.In vitro cell viability and in vivo studies showed that FA-PMDNPs more effectively inhibited the proliferation of FA receptor(FR)-overexpressing breast cancer cells(4T1)than the pure drugs.Consequently,these results demonstrated that FA-PMDNPs could be effectively targeted at cancer cells compared with free drugs,indicating their strong potential as efficient multi-drug-carrying nano-platforms for cancer treatment.展开更多
文摘Converting sustainable solar energy into hydrogen energy over semiconductor-based photocatalytic materials provides an alternative to fossil fuel consumption.However,efficient photocatalytic splitting of water to realize carbon-free hydrogen production remains a challenge.Heterojunction photocatalysts with well-defined dimensionality and perfectly matched interfaces are promising for achieving highly efficient solar-to-hydrogen conversion.Herein,we report the fabrication of a novel type of protonated graphitic carbon nitride(PCN)/Ti3C2 MXene heterojunctions with strong interfacial interactions.As expected,the two-dimensional(2D)PCN/2D Ti3C2 MXene interface heterojunction achieves a highly improved hydrogen evolution rate(2181μmol∙g‒1)in comparison with bulk g-C3N4(393μmol∙g‒1)and protonated g-C3N4(816μmol∙g‒1).The charge-regulated surfaces of PCN and the accelerated charge transport at the face-to-face 2D/2D Schottky heterojunction interface are the major contributors to the excellent hydrogen evolution performance of the composite photocatalyst.
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.
文摘Solar-powered photocatalytic hydrogen production from water using semiconductors provides an eco-friendly and promising approach for converting solar energy into hydrogen fuel.Bulk semiconductors generally suffer from certain limitations,such as poor visible-light utilization,rapid recombination of charge carriers,and low catalytic capability.The key challenge is to develop visible-light-driven heterojunction photocatalysts that are stable and highly active during the water splitting process.Here,we demonstrate the integration of one-dimensional(1D)Cd S nanorods with two-dimensional(2D)1 T-phase dominated WS_(2) nanosheets for constructing mixed-dimensional heterojunctions for the photocatalytic hydrogen evolution reaction(HER).The resulting 1D CdS/2D WS_(2) nanoheterojunction exhibited an ultrahigh hydrogen-evolution activity of~70 mmol·g^(-1)·h^(-1) that was visible to the naked eye,as well as long-term stability under visible light illumination.The results reveal that the synergy of hybrid nanoarchitectures and intimate interfacial contact between the 1D Cd S nanorods and 1T-phase dominated 2D WS_(2) nanosheets facilitates charge carrier transport,which is beneficial for achieving superior hydrogen evolution.
文摘The ethanol oxidation reaction is a significant anodic reaction for direct alcohol fuel cells.The most commonly used catalysts for this reaction are Pt‐based materials;however,Pt‐based electrocatalysts cause carbon monoxide poisoning with intermediates before the complete transformation of alcohol to CO_(2).Herein,we present hierarchical AgAu bimetallic nanoarchitectures for ethanol electrooxidation,which were fabricated via a partial galvanic reduction reaction between Ag and HAuCl_(4).The ethanol electrooxidation performance of the optimal AgAu nanohybrid was increased to 1834 mA mg^(‒1),which is almost 10 times higher than that of the pristine Au catalyst(190 mA mg^(‒1))in alkaline solutions.This was achieved by introducing Ag into the Au catalyst and controlling the time of the replacement reaction.The heterostructure also presents a higher current density than that of commercial Pt/C(1574 mA mg^(‒1)).Density functional theory calculations revealed that the enhanced activity and stability may stem from unavoidable defects on the surface of the integrated AgAu nanoarchitectures.Ethanol oxidation reactions over these defects are more energetically favorable,which facilitates the oxidative removal of carbonaceous poison and boosts the combination with radicals on adjacent Au active sites.
基金National Natural Science Foundation of China(Grant No.21877061)Natural Science Foundation of Jiangsu Province(Grant No.BK20171448)National and Local Joint Engineering Research Center of Biomedical Functional Materials。
文摘Multi-drug delivery focuses on different signaling pathways in cancer cells and has synergistic antiproliferative effects.In this manuscript,we developed folic acid(FA)-conjugated polymeric multi-drug nanoparticles(FA-PMDNPs)consisting of poly-L-lysine(PLL)and poly glutamic-conjugated PTX/GEM(PGA-PTX and PGA-GEM)for FA receptor-targeted synergistic breast cancer therapy.The carboxyl-rich structure of PGA provided plenty reaction sites and negative charge for drug loading.Transmission electron microscopy(TEM)results showed that FA-PMDNPs had uniform particle size and spherical morphology.The hemolysis study proved that FA-PMDNPs had good biocompatibility.In vitro cell viability and in vivo studies showed that FA-PMDNPs more effectively inhibited the proliferation of FA receptor(FR)-overexpressing breast cancer cells(4T1)than the pure drugs.Consequently,these results demonstrated that FA-PMDNPs could be effectively targeted at cancer cells compared with free drugs,indicating their strong potential as efficient multi-drug-carrying nano-platforms for cancer treatment.