Exclusive responsiveness to ultraviolet light (~3.2 eV) and high photogenerated charge recombination rate are the two primary drawbacks of pure TiO_(2). We combined N-doped graphene quantum dots (N-GQDs), morphology r...Exclusive responsiveness to ultraviolet light (~3.2 eV) and high photogenerated charge recombination rate are the two primary drawbacks of pure TiO_(2). We combined N-doped graphene quantum dots (N-GQDs), morphology regulation, and heterojunction construction strategies to synthesize N-GQD/N-doped TiO_(2)/P-doped porous hollow g-C_(3)N_(4) nanotube (PCN) composite photocatalysts (denoted as G-TPCN). The optimal sample (G-TPCN doped with 0.1wt% N-GQD, denoted as 0.1% G-TPCN) exhibits significantly enhanced photoabsorption, which is attributed to the change in bandgap caused by elemental doping (P and N), the improved light-harvesting resulting from the tube structure, and the upconversion effect of N-GQDs. In addition, the internal charge separation and transfer capability of0.1% G-TPCN are dramatically boosted, and its carrier concentration is 3.7, 2.3, and 1.9 times that of N-TiO_(2), PCN, and N-TiO_(2)/PCN(TPCN-1), respectively. This phenomenon is attributed to the formation of Z-scheme heterojunction between N-TiO_(2) and PCNs, the excellent electron conduction ability of N-GQDs, and the short transfer distance caused by the porous nanotube structure. Compared with those of N-TiO_(2), PCNs, and TPCN-1, the H2 production activity of 0.1%G-TPCN under visible light is enhanced by 12.4, 2.3, and 1.4times, respectively, and its ciprofloxacin (CIP) degradation rate is increased by 7.9, 5.7, and 2.9 times, respectively. The optimized performance benefits from excellent photoresponsiveness and improved carrier separation and migration efficiencies. Finally, the photocatalytic mechanism of 0.1% G-TPCN and five possible degradation pathways of CIP are proposed. This study clarifies the mechanism of multiple modification strategies to synergistically improve the photocatalytic performance of 0.1% G-TPCN and provides a potential strategy for rationally designing novel photocatalysts for environmental remediation and solar energy conversion.展开更多
The high theoretical capacity and low discharge potential of silicon have attracted much attention on Si-based anodes. Herein, hollow porous SiO2 nanocubes have been prepared via a two-step hard-template process and e...The high theoretical capacity and low discharge potential of silicon have attracted much attention on Si-based anodes. Herein, hollow porous SiO2 nanocubes have been prepared via a two-step hard-template process and evaluated as electrode materials for lithium-ion batteries. The hollow porous SiO2 nanocubes exhibited a reversible capacity of 919 mAh/g over 30 cycles. The excellent property could be attributed to the unique hollow nanostructure with large volume interior and numerous crevices in the shell, which could accommodate the volume change and alleviate the structural strain during Li ions insertion and extraction, as well as allow rapid access of Li ions during charge/discharge cycling. It is found that the formation of irreversible or reversible lithium silicates in the anodes determines the capacity of a deep-cycle battery, fast transportation of Li ions in hollow porous SiO2 nanocubes is preferred to form Li2O and Si, contributing to the high reversible capacity. The hollow porous SiO2 nanocubes have great potential applications for Li-ion batteries due to their remarkable electrochemical performance and low cost.展开更多
The selective hydrogenolysis of glycerol exhibits great prospects,while the catalysts with high selectivity and activity are still missing and need to be created urgently.Herein,we report the synthesis of hollow mesop...The selective hydrogenolysis of glycerol exhibits great prospects,while the catalysts with high selectivity and activity are still missing and need to be created urgently.Herein,we report the synthesis of hollow mesoporous Pt/WO_(x)/SiO_(2)-TiO_(2)nanosphere catalysts with bi-functional interfaces synergistically for high efficiency conversion of glycerol to 1,3-propanediol.The hollow mesoporous Pt/WO_(x)/SiO_(2)-TiO_(2)catalysts show a typical brick-concrete liked framework with a high surface area(179.3 m^(2)·g^(-1)),large mesopore size(10.6 nm),uniform particle size(~400 nm),and ultrathin shell thickness(~75 nm).The brick anatase nanocrystals and concrete amorphous SiO_(2)networks can selectively rivet Pt nanoparticles and WO_(x)nanocluster species,respectively,thus constructing two interfaces for effective adsorption,rapidly catalytic dehydration and hydrogenation processes.The hollow mesoporous Pt/WO_(x)/SiO_(2)-TiO_(2)catalysts deliver a high selectivity of 53.8%for 1,3-propanediol(1,3-PDO)at a very high glycerol conversion of 85.0%.As a result,a favorable 1,3-PDO yield of 45.7%can be obtained with excellent stability,which is among the best performances of previously reported catalysts.This work paves a new way to synthesize catalysts with high selectivity,high activity and high stability.展开更多
The development of reliable catalysts with both excellent activity and recyclability for carbon dioxide(CO_(2))hydrogenation is challenging.Herein,a ternary hybrid heterogeneous catalyst,involving mononuclear Ru compl...The development of reliable catalysts with both excellent activity and recyclability for carbon dioxide(CO_(2))hydrogenation is challenging.Herein,a ternary hybrid heterogeneous catalyst,involving mononuclear Ru complex,N,P-containing porous organic polymers(POPs),and mesoporous hollow carbon spheres(Ru^(3+)-POPs@MHCS)is reported for CO_(2)hydrogenation to formate.Based on comprehensive structural analyses,we demonstrated that Ru^(3+)-POPs were successfully immobilized within MHCS.The optimized Ru^(3+)-0.5POPs@MHCS catalyst,which was obtained with about 5 wt.%Ru^(3+)and 0.5 mmol POPs polymers confined into 0.3 g MHCS,exhibited high catalytic activity for CO_(2)hydrogenation to formate(turnover number(TON)>1,200 for 24 h under mild reaction conditions(4.0 MPa,120℃))and improved durability,compared to Ru^(3+)catalysts without POPs polymers(Ru^(3+)-MHCS)and unencapsulated MHCS(Ru^(3+)-0.5POPs)catalysts.The improved catalytic performance is attributed to the high surface area and large pore volume of MHCS which favors dispersion and stabilization of Ru^(3+)-POPs.Furthermore,the MHCS and POPs showed high CO_(2)adsorption ability.Ru^(3+)-POPs encapsulated into MHCS reduces the activation energy barrier for CO_(2)hydrogenation to formate.展开更多
Hollow mesoporous silica(HM-SiO_(2))was prepared by the improved stober method.On this basis,HM-SiO_(2) was dispersed in an alkaline solution for surface etching.Meanwhile,calcium source was introduced to combine with...Hollow mesoporous silica(HM-SiO_(2))was prepared by the improved stober method.On this basis,HM-SiO_(2) was dispersed in an alkaline solution for surface etching.Meanwhile,calcium source was introduced to combine with SiO_(3)^(2−) on the surface to form a CaSiO_(3) shell layer and an unprecedent SiO_(2)@CaSiO_(3) sphere with a hollow double-shell structure was obtained.The as-synthesized SiO_(2)@CaSiO_(3) was characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),N_(2)-BET,IR and UV-Vis techniques,and its sustained release capacity of doxorubicin(DOX)loading was investigated.The drug loading capacity can be achieved to 0.692 mg DOX/mg SiO_(2)@CaSiO_(3),exhibiting pH-responsivity under low pH conditions.展开更多
Electrochemical oxygen reduction is a promising approach for the sustainable decentralized production of H_(2)O_(2),but its viable commercialization is hindered by the insufficient development of efficient electrocata...Electrochemical oxygen reduction is a promising approach for the sustainable decentralized production of H_(2)O_(2),but its viable commercialization is hindered by the insufficient development of efficient electrocatalysts.Here,we demonstrate a promising carbon-based catalyst,consisting of oxygen-rich hollow mesoporous carbon spheres(HMCSs),for selective oxygen reduction to H_(2)O_(2).The as-prepared HMCS exhibits high onset potential(0.82 V)and half-wave potential(0.76 V),delivering a significant positive shift compared with its oxygen-scarce counterparts and commercial Vulcan carbon.Moreover,excellent H2O2 selectivity(above 95%)and electrochemical stability(7%attenuation after 10 h operation)make this material a state-of-the-art catalyst for electrochemical H_(2)O_(2) production.The outstanding performance arises from a combination of several aspects,such as porous structure-facilitation of mass transport,large surface area,and proper distribution of oxygen-containing functional groups modification on the surface.Furthermore,the proposed oxygen reduction reaction(ORR)mechanism on HMCS surface reveals that-OH functional groups help promote the first electron transfer process while other oxygen modification facilitate the second electron transfer.展开更多
Core-shell materials are promising broadband electromagnetic(EM)absorption materials since the highly component manipulation performance,interfacial effect etc.Herein,a well-defined core-shell shaped structure constru...Core-shell materials are promising broadband electromagnetic(EM)absorption materials since the highly component manipulation performance,interfacial effect etc.Herein,a well-defined core-shell shaped structure constructed by 2-dimensional Mo S_(2)nanosheets-coated porous hollow carbon has been successfully designed with controlled pore-sizes of the core,adjustable shell content,and structure.By effectively optimizing the parameters for these factors,the as-prepared hierarchical porous hollow C@Mo S_(2)sample enables an ultra-width EM absorption ability(covering 11.4-18.0 GHz)at a thickness of only 2.0 mm.The detailed contributions of each component and structure on the excellent EM absorption capability have been investigated.These encouraging results indicate that the development of core-shell composites with multiple controllable physical factors is of great significance for the future ultra-wideband electromagnetic absorbers.展开更多
Even though various nickel-nitrogen-carbon(Ni-N-C)combinations are prospective low-cost catalysts for the CO_(2)electroreduction reaction(CO_(2)RR),which is one avenue for attaining carbon neutrality,the detailed role...Even though various nickel-nitrogen-carbon(Ni-N-C)combinations are prospective low-cost catalysts for the CO_(2)electroreduction reaction(CO_(2)RR),which is one avenue for attaining carbon neutrality,the detailed role of different N species has hardly been investigated.Here,we report a hollow porous N-doped carbon nanofiber with NiNX-pyridinic N active species(denoted as h-Ni-N-C)developed using a facile electrospinning and SiO_(2)space-confined pyrolysis strategy.The NiNX-pyridinic N species are facilely generated during the pyrolysis process,giving rise to enhanced activity and selectivity for the CO_(2)RR.The optimized h-Ni-N-C exhibits a high CO Faradaic efficiency of 91.3%and a large current density of−15.1 mA cm^(−2)at−0.75 V versus reversible hydrogen electrode in an H-cell.Density functional theory(DFT)results show that NiN4-pyridinic N species demonstrate a lower free energy for the catalyst's rate-determining step than isolated NiN4 and pyridinic N species,without affecting the desorption of CO∗intermediate.展开更多
基金financially supported by the National Natural Science Foundation of China (Nos.U2002212,52102058,52204414,52204413,and 52204412)the National Key R&D Program of China (Nos.2021YFC1910504,2019YFC1907101,2019YFC1907103,and 2017YFB0702304)+7 种基金the Key R&D Program of Ningxia Hui Autonomous Region,China (Nos.2021BEG01003 and2020BCE01001)the Xijiang Innovation and Entrepreneurship Team,China (No.2017A0109004)the Macao Young Scholars Program (No.AM2022024),Chinathe Beijing Natural Science Foundation (Nos.L212020 and 2214073),Chinathe Guangdong Basic and Applied Basic Research Foundation,China (Nos.2021A1515110998 and 2020A1515110408)the China Postdoctoral Science Foundation (No.2022M710349)the Fundamental Research Funds for the Central Universities,China (Nos.FRF-BD-20-24A,FRF-TP-20-031A1,FRF-IC-19-017Z,and 06500141)the Integration of Green Key Process Systems MIIT and Scientific and Technological Innovation Foundation of Foshan,China(Nos.BK22BE001 and BK21BE002)。
文摘Exclusive responsiveness to ultraviolet light (~3.2 eV) and high photogenerated charge recombination rate are the two primary drawbacks of pure TiO_(2). We combined N-doped graphene quantum dots (N-GQDs), morphology regulation, and heterojunction construction strategies to synthesize N-GQD/N-doped TiO_(2)/P-doped porous hollow g-C_(3)N_(4) nanotube (PCN) composite photocatalysts (denoted as G-TPCN). The optimal sample (G-TPCN doped with 0.1wt% N-GQD, denoted as 0.1% G-TPCN) exhibits significantly enhanced photoabsorption, which is attributed to the change in bandgap caused by elemental doping (P and N), the improved light-harvesting resulting from the tube structure, and the upconversion effect of N-GQDs. In addition, the internal charge separation and transfer capability of0.1% G-TPCN are dramatically boosted, and its carrier concentration is 3.7, 2.3, and 1.9 times that of N-TiO_(2), PCN, and N-TiO_(2)/PCN(TPCN-1), respectively. This phenomenon is attributed to the formation of Z-scheme heterojunction between N-TiO_(2) and PCNs, the excellent electron conduction ability of N-GQDs, and the short transfer distance caused by the porous nanotube structure. Compared with those of N-TiO_(2), PCNs, and TPCN-1, the H2 production activity of 0.1%G-TPCN under visible light is enhanced by 12.4, 2.3, and 1.4times, respectively, and its ciprofloxacin (CIP) degradation rate is increased by 7.9, 5.7, and 2.9 times, respectively. The optimized performance benefits from excellent photoresponsiveness and improved carrier separation and migration efficiencies. Finally, the photocatalytic mechanism of 0.1% G-TPCN and five possible degradation pathways of CIP are proposed. This study clarifies the mechanism of multiple modification strategies to synergistically improve the photocatalytic performance of 0.1% G-TPCN and provides a potential strategy for rationally designing novel photocatalysts for environmental remediation and solar energy conversion.
文摘The high theoretical capacity and low discharge potential of silicon have attracted much attention on Si-based anodes. Herein, hollow porous SiO2 nanocubes have been prepared via a two-step hard-template process and evaluated as electrode materials for lithium-ion batteries. The hollow porous SiO2 nanocubes exhibited a reversible capacity of 919 mAh/g over 30 cycles. The excellent property could be attributed to the unique hollow nanostructure with large volume interior and numerous crevices in the shell, which could accommodate the volume change and alleviate the structural strain during Li ions insertion and extraction, as well as allow rapid access of Li ions during charge/discharge cycling. It is found that the formation of irreversible or reversible lithium silicates in the anodes determines the capacity of a deep-cycle battery, fast transportation of Li ions in hollow porous SiO2 nanocubes is preferred to form Li2O and Si, contributing to the high reversible capacity. The hollow porous SiO2 nanocubes have great potential applications for Li-ion batteries due to their remarkable electrochemical performance and low cost.
基金This work was supported by the National Key R&D Program of China(Nos.2022YFA1503501 and 2018YFA0209401)the National Natural Science Foundation of China(Nos.22088101,21975050 and U21A20329)+2 种基金the Program of Shanghai Academic Research Leader(No.21XD1420800)the Shanghai Pilot Program for Basic Research-Fudan University 21TQ1400100(No.21TQ008)the Fundamental Research Funds for the Central Universities(No.20720220010).
文摘The selective hydrogenolysis of glycerol exhibits great prospects,while the catalysts with high selectivity and activity are still missing and need to be created urgently.Herein,we report the synthesis of hollow mesoporous Pt/WO_(x)/SiO_(2)-TiO_(2)nanosphere catalysts with bi-functional interfaces synergistically for high efficiency conversion of glycerol to 1,3-propanediol.The hollow mesoporous Pt/WO_(x)/SiO_(2)-TiO_(2)catalysts show a typical brick-concrete liked framework with a high surface area(179.3 m^(2)·g^(-1)),large mesopore size(10.6 nm),uniform particle size(~400 nm),and ultrathin shell thickness(~75 nm).The brick anatase nanocrystals and concrete amorphous SiO_(2)networks can selectively rivet Pt nanoparticles and WO_(x)nanocluster species,respectively,thus constructing two interfaces for effective adsorption,rapidly catalytic dehydration and hydrogenation processes.The hollow mesoporous Pt/WO_(x)/SiO_(2)-TiO_(2)catalysts deliver a high selectivity of 53.8%for 1,3-propanediol(1,3-PDO)at a very high glycerol conversion of 85.0%.As a result,a favorable 1,3-PDO yield of 45.7%can be obtained with excellent stability,which is among the best performances of previously reported catalysts.This work paves a new way to synthesize catalysts with high selectivity,high activity and high stability.
基金supported by JSPS KAKENHI(Nos.18K14056 and 19H00838)JST,PRESTO(No.JPMJPR19T3)+3 种基金Japan.A part of this work was supported by the cooperative research program of“Network Joint Research Center for Materials and Devices”(No.20211069).support of the International Joint Research Promotion Program at Osaka University.G.X.Y.gratefully acknowledges the financial support from the China Scholarship Council(No.201808310132)Y.K.,K.M.,and H.Y.thank the Elements Strategy Initiative of MEXT(No.JPMXP0112101003)Japan.The synchrotron radiation experiments for XAFS measurement were performed at the BL01B1 beamline in SPring-8 with approval from JASRI(Nos.2019B1114 and 2020A1064).
文摘The development of reliable catalysts with both excellent activity and recyclability for carbon dioxide(CO_(2))hydrogenation is challenging.Herein,a ternary hybrid heterogeneous catalyst,involving mononuclear Ru complex,N,P-containing porous organic polymers(POPs),and mesoporous hollow carbon spheres(Ru^(3+)-POPs@MHCS)is reported for CO_(2)hydrogenation to formate.Based on comprehensive structural analyses,we demonstrated that Ru^(3+)-POPs were successfully immobilized within MHCS.The optimized Ru^(3+)-0.5POPs@MHCS catalyst,which was obtained with about 5 wt.%Ru^(3+)and 0.5 mmol POPs polymers confined into 0.3 g MHCS,exhibited high catalytic activity for CO_(2)hydrogenation to formate(turnover number(TON)>1,200 for 24 h under mild reaction conditions(4.0 MPa,120℃))and improved durability,compared to Ru^(3+)catalysts without POPs polymers(Ru^(3+)-MHCS)and unencapsulated MHCS(Ru^(3+)-0.5POPs)catalysts.The improved catalytic performance is attributed to the high surface area and large pore volume of MHCS which favors dispersion and stabilization of Ru^(3+)-POPs.Furthermore,the MHCS and POPs showed high CO_(2)adsorption ability.Ru^(3+)-POPs encapsulated into MHCS reduces the activation energy barrier for CO_(2)hydrogenation to formate.
基金supported by the National Natural Science Foundation of China(No.21961021)the Natural Science Foundation of Jiangxi Province,China(No.20202ACB203001).
文摘Hollow mesoporous silica(HM-SiO_(2))was prepared by the improved stober method.On this basis,HM-SiO_(2) was dispersed in an alkaline solution for surface etching.Meanwhile,calcium source was introduced to combine with SiO_(3)^(2−) on the surface to form a CaSiO_(3) shell layer and an unprecedent SiO_(2)@CaSiO_(3) sphere with a hollow double-shell structure was obtained.The as-synthesized SiO_(2)@CaSiO_(3) was characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),N_(2)-BET,IR and UV-Vis techniques,and its sustained release capacity of doxorubicin(DOX)loading was investigated.The drug loading capacity can be achieved to 0.692 mg DOX/mg SiO_(2)@CaSiO_(3),exhibiting pH-responsivity under low pH conditions.
基金This work was financially supported by the Natural Sciences and Engineering Research Council of Canada(NSERC),through the Discovery Grant Program(No.RGPIN-2018-06725)the Discovery Accelerator Supplement Grant program(No.RGPAS2018-522651)by the New Frontiers in Research FundExploration program(No.NFRFE-2019-00488).
文摘Electrochemical oxygen reduction is a promising approach for the sustainable decentralized production of H_(2)O_(2),but its viable commercialization is hindered by the insufficient development of efficient electrocatalysts.Here,we demonstrate a promising carbon-based catalyst,consisting of oxygen-rich hollow mesoporous carbon spheres(HMCSs),for selective oxygen reduction to H_(2)O_(2).The as-prepared HMCS exhibits high onset potential(0.82 V)and half-wave potential(0.76 V),delivering a significant positive shift compared with its oxygen-scarce counterparts and commercial Vulcan carbon.Moreover,excellent H2O2 selectivity(above 95%)and electrochemical stability(7%attenuation after 10 h operation)make this material a state-of-the-art catalyst for electrochemical H_(2)O_(2) production.The outstanding performance arises from a combination of several aspects,such as porous structure-facilitation of mass transport,large surface area,and proper distribution of oxygen-containing functional groups modification on the surface.Furthermore,the proposed oxygen reduction reaction(ORR)mechanism on HMCS surface reveals that-OH functional groups help promote the first electron transfer process while other oxygen modification facilitate the second electron transfer.
基金financially supported by the National Natural Science Foundation of China(No.51602154)the Fundamental Research Funds for the Center Universities(No.NE2018103)+2 种基金the Aeronautical Science Foundation of China(No.2018ZF52071)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PA)the Qingchuang Talents Induction Program of Shandong Higher Education Institution(Research and Innovation Team of Structural-Functional Polymer Composites)。
文摘Core-shell materials are promising broadband electromagnetic(EM)absorption materials since the highly component manipulation performance,interfacial effect etc.Herein,a well-defined core-shell shaped structure constructed by 2-dimensional Mo S_(2)nanosheets-coated porous hollow carbon has been successfully designed with controlled pore-sizes of the core,adjustable shell content,and structure.By effectively optimizing the parameters for these factors,the as-prepared hierarchical porous hollow C@Mo S_(2)sample enables an ultra-width EM absorption ability(covering 11.4-18.0 GHz)at a thickness of only 2.0 mm.The detailed contributions of each component and structure on the excellent EM absorption capability have been investigated.These encouraging results indicate that the development of core-shell composites with multiple controllable physical factors is of great significance for the future ultra-wideband electromagnetic absorbers.
基金This work was financially supported by National Key Research and Development Program of China(2018YFB1502503).
文摘Even though various nickel-nitrogen-carbon(Ni-N-C)combinations are prospective low-cost catalysts for the CO_(2)electroreduction reaction(CO_(2)RR),which is one avenue for attaining carbon neutrality,the detailed role of different N species has hardly been investigated.Here,we report a hollow porous N-doped carbon nanofiber with NiNX-pyridinic N active species(denoted as h-Ni-N-C)developed using a facile electrospinning and SiO_(2)space-confined pyrolysis strategy.The NiNX-pyridinic N species are facilely generated during the pyrolysis process,giving rise to enhanced activity and selectivity for the CO_(2)RR.The optimized h-Ni-N-C exhibits a high CO Faradaic efficiency of 91.3%and a large current density of−15.1 mA cm^(−2)at−0.75 V versus reversible hydrogen electrode in an H-cell.Density functional theory(DFT)results show that NiN4-pyridinic N species demonstrate a lower free energy for the catalyst's rate-determining step than isolated NiN4 and pyridinic N species,without affecting the desorption of CO∗intermediate.
