Photocatalytic H_(2)O_(2)production provides a clean and sustainable strategy for artificial photosynthesis.Herein,an inorganic/organic composite photocatalyst was fabricated by in-situ growth of CdS nanoparticles on ...Photocatalytic H_(2)O_(2)production provides a clean and sustainable strategy for artificial photosynthesis.Herein,an inorganic/organic composite photocatalyst was fabricated by in-situ growth of CdS nanoparticles on the surface of resorcinol-formaldehyde(RF)resin spheres.RF spheres played multiple roles:(i)acting as a substrate for the growth of CdS and constructing a core-shell structure with seamless con-tact;(ⅱ)improving visible light absorption of CdS;(ⅲ)forming an S-scheme heterojunction with CdS and promoting the charge separation and transfer.Consequently,under visible light illumination,CdS/RF composite presented remarkably enhanced H_(2)O_(2)production activity.Its H_(2)O_(2)yield in 60 min was 801μmol L^(-1),which was 5.2 and 1.5 times higher than that of RF spheres and CdS hollow spheres,respectively.The charge migration between CdS and RF followed the S-scheme photocatalytic mechanism,which was verified by work function measurement,ex-situ and in-situ irradiated X-ray photoelectron spectroscopy.This work brings a novel insight into designing RF-based inorganic/organic S-scheme heterojunction pho-tocatalysts for efficient H_(2)O_(2)production.展开更多
Obtaining large specific surface areas(SSA)for carbon xerogels poses a significant challenge due to the inevitable volume shrinkage of xerogel.Here,the Zn^(2+) coordination-catalyzed in-situ polymerization approach wa...Obtaining large specific surface areas(SSA)for carbon xerogels poses a significant challenge due to the inevitable volume shrinkage of xerogel.Here,the Zn^(2+) coordination-catalyzed in-situ polymerization approach was proposed to fabricate xerogels with a low shrinkage of 13.03% and a short preparation period of 24 h.In resorcinolformaldehyde(RF)polymerization,ZnCl_(2) could accelerate the reaction kinetics through the coordination of the Zn^(2+) and hydroxyl groups.The gel network with adjustable RF particles(46.5 nm-1.89μm)and narrow neck structures was constructed by changing ZnCl_(2) and ethanol contents,which could resist volume shrinkage during atmospheric drying without solvent exchange.The activated carbon xerogels(ACXs)with hierarchical structure were designed by one-step carbonization/activation due to the pore-forming of ZnCl_(2).The obtained ACXs showed a large SSA of 1689 m^(2)/g,multi-dyes adsorption capacity(methylene blue,Congo red,methyl orange,and Sudan Ⅲ were 625.90,359.46,320.69,and 453.92 mg/g,respectively),and reusability of 100%.The maximum monolayer MB adsorption capacity was 630.28 mg/g.This work presents an efficient strategy to design porous nanomaterials with low shrinkage and large SSA,which illustrates promising applications in separation,adsorption,and photoelectric catalysis.展开更多
Solar-powered H_(2)O_(2)synthesis from water and oxygen presents a potential strategy in the industrial and environmental domains.However,insufficient light absorption,poor charge separation efficiency,and the same or...Solar-powered H_(2)O_(2)synthesis from water and oxygen presents a potential strategy in the industrial and environmental domains.However,insufficient light absorption,poor charge separation efficiency,and the same or nearby catalytic sites for the photocatalysts limit the activity of H_(2)O_(2)production.Herein,an ultraviolet-visible-near-infrared light responsive S-scheme heterojunction is created by growing ZnIn_(2)S_(4)(ZIS)subunits firmly on a core of resorcinol-formaldehyde(RF)sphere.The enhanced full-spectrum light response ZIS/RF core-shell structure is evidenced by UV/Vis-NIR diffuse reflectance spectra(DRS).In situ irradiation X-ray photoelectron spectroscopy(XPS)investigation confirms an S-scheme charge transfer mechanism between RF and ZIS.A directional interfacial electric field(IEF)drives the unique spatial separation feature of constructed heterojunction photoexcited carriers and redox centers through the S-scheme transfer pathway with H_(2)O_(2)production.Under solar light irradiation,the optimized ZIS/RF with core-shell structure shows a robust apparent quantum efficiency(AQY)up to 22.5%at 420 nm,1%at 720 nm,and 0.2%at 800 nm.With the key reaction intermediates determined by calculating the average number of transferred electrons and oxygen-reactive species,a possible full-spectrum-light-driven redox mechanism of H_(2)O_(2)synthesis is provided.展开更多
Nano-pore carbon aerogels were prepared by the sol-gel polymerization of resorcinol (1,3-dihydroxybenzene)(C6H4(OH)2) with formaldehyde (HCHO) in a slightly basic aqueous solution, followed by super-critical drying un...Nano-pore carbon aerogels were prepared by the sol-gel polymerization of resorcinol (1,3-dihydroxybenzene)(C6H4(OH)2) with formaldehyde (HCHO) in a slightly basic aqueous solution, followed by super-critical drying under liquid carbon dioxide as super-critical media and carbonization at 700 ℃ under N2 gas atmosphere. The key of the work is to fabricate carbon aerogels with controllable nano-pore structure, which means extremely high surface area and sharp pore size distribution. Aiming to investigate the effects of preparation conditions on the gelation process, the bulk density, and the physical and chemical structure of the resultant carbon aerogels, the molar ratio of R/C (resorcinol to catalyst) and the amount of distilled water were varied, consequently two different sets of samples, with series of R/C ratio and RF/W (Resorcinol-Formaldehyde to water, or the content of reactant) ratio, were prepared. The result of N2 adsorption/desorption experiment at 77 K shows that the pore sizes decreasing from 11.4 down to 2.2 nm with the increasing of the molar ratio of R/C from 100 to 400, and/or, the pore sizes decreasing from 3.8 down to 1.6 nm with the increasing of reactant content from 0.4 to 0.6.展开更多
Formaldehyde(HCHO)as an indoor air pollutant released by new furniture and decorative materials is of great concern.Developing a self-cleaning device to remove HCHO is an ideal way to improve indoor air quality.In thi...Formaldehyde(HCHO)as an indoor air pollutant released by new furniture and decorative materials is of great concern.Developing a self-cleaning device to remove HCHO is an ideal way to improve indoor air quality.In this study,a self-cleaning window with a multilayered structure constructed from fluorinedoped tin oxide/bismuth tungstate/resorcinol-formaldehyde resin(FTO/Bi_(2)WO_(6)/RF)has been fabricated,which is capable of degrading HCHO in natural indoor condition.The as-fabricated device could utilize the natural room light and promote the generation and transfer of the photocatalytic carriers in Bi_(2)WO_(6),which subsequently delivers a good catalytic oxygen reduction efficiency in RF to produce hydrogen peroxide(H_(2)O_(2)).The as-synthesized H_(2)O_(2)could further split into hydroxyl radicals(•OH),then oxide the HCHO molecules in the air.The present study demonstrates a novel and efficient strategy to fabricate a transparent multifunctional window for self-cleaning indoor gaseous pollutants,the concept is of great importance to be expanded in a broad range of indoor furniture for in-house air pollution control.展开更多
Transition metal dichalcogenide(TMD)materials have recently demonstrated exceptional supercapacitor properties after conversion to a metallic phase,which increases the conductivity of the network.However,freestanding,...Transition metal dichalcogenide(TMD)materials have recently demonstrated exceptional supercapacitor properties after conversion to a metallic phase,which increases the conductivity of the network.However,freestanding,exfoliated transition metal dichalcogenide films exhibit surface areas far below their theoretical maximum(1.2%),can fail during electrochemical operation due to poor mechanical properties,and often require pyrophoric chemicals to process.On the other hand,pyrolyzed carbon aerogels exhibit extraordinary specific surface areas for double layer capacitance,high conductivity,and a strong mechanical network of covalent chemical bonds.In this paper,we demonstrate the scalable,rapid nanomanufacturing of TMD(MoS2 and WS2)and carbon aerogel composites,favoring liquid-phase exfoliation to avoid pyrophoric chemicals.The aerogel matrix support enhances conductivity of the composite and the synthesis can complete in 30 min.We find that the addition of transition metal dichalcogenides does not impact the structure of the aerogel,which maintains a high specific surface area up to 620 m^(2) g−1 with peak pore radii of 10 nm.While supercapacitor tests of the aerogels yield capacitances around 80 F g^(−1) at the lowest applied currents,the aerogels loaded with TMD’s exhibit volumetric capacitances up to 127% greater than the unloaded aerogels.In addition,the WS2 aerogels show excellent cycling stability with no capacitance loss over 2000 cycles,as well as markedly better rate capability and lower charge transfer resistance compared to their MoS2-loaded counterparts.We hypothesize that these differences in performance stem from differences in contact resistance and in the favorability of ion adsorption on the chalcogenides.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52173065,51932007,22278324,52073223,22262012 and U1905215)China Postdoctoral Science Foundation(No.2022M710137)the Natural Science Foundation of Hubei Province of China(No.2022CFA001).
文摘Photocatalytic H_(2)O_(2)production provides a clean and sustainable strategy for artificial photosynthesis.Herein,an inorganic/organic composite photocatalyst was fabricated by in-situ growth of CdS nanoparticles on the surface of resorcinol-formaldehyde(RF)resin spheres.RF spheres played multiple roles:(i)acting as a substrate for the growth of CdS and constructing a core-shell structure with seamless con-tact;(ⅱ)improving visible light absorption of CdS;(ⅲ)forming an S-scheme heterojunction with CdS and promoting the charge separation and transfer.Consequently,under visible light illumination,CdS/RF composite presented remarkably enhanced H_(2)O_(2)production activity.Its H_(2)O_(2)yield in 60 min was 801μmol L^(-1),which was 5.2 and 1.5 times higher than that of RF spheres and CdS hollow spheres,respectively.The charge migration between CdS and RF followed the S-scheme photocatalytic mechanism,which was verified by work function measurement,ex-situ and in-situ irradiated X-ray photoelectron spectroscopy.This work brings a novel insight into designing RF-based inorganic/organic S-scheme heterojunction pho-tocatalysts for efficient H_(2)O_(2)production.
基金supported by the National Key Research and Development Program of China(No.2023YFB3711501)Shanghai Industrial Collaborative Innovation Leading Group Office(No.XTCX-KJ-2023-53)+3 种基金the Fundamental Research Funds for the Central Universities(No.23D110609)the Open Research Fund of Songshan Lake Materials Laboratory(No.2022SLABFN09)the Foundation of State Key Laboratory of Biobased Material and Green Papermaking,Qilu University of Technology,Shandong Academy of Sciences(No.GZKF202231)the Fundamental Research Funds for the Central Universities and Graduate Student Innovation Fund of Donghua University(No.CUSF-DH-D-2022012).
文摘Obtaining large specific surface areas(SSA)for carbon xerogels poses a significant challenge due to the inevitable volume shrinkage of xerogel.Here,the Zn^(2+) coordination-catalyzed in-situ polymerization approach was proposed to fabricate xerogels with a low shrinkage of 13.03% and a short preparation period of 24 h.In resorcinolformaldehyde(RF)polymerization,ZnCl_(2) could accelerate the reaction kinetics through the coordination of the Zn^(2+) and hydroxyl groups.The gel network with adjustable RF particles(46.5 nm-1.89μm)and narrow neck structures was constructed by changing ZnCl_(2) and ethanol contents,which could resist volume shrinkage during atmospheric drying without solvent exchange.The activated carbon xerogels(ACXs)with hierarchical structure were designed by one-step carbonization/activation due to the pore-forming of ZnCl_(2).The obtained ACXs showed a large SSA of 1689 m^(2)/g,multi-dyes adsorption capacity(methylene blue,Congo red,methyl orange,and Sudan Ⅲ were 625.90,359.46,320.69,and 453.92 mg/g,respectively),and reusability of 100%.The maximum monolayer MB adsorption capacity was 630.28 mg/g.This work presents an efficient strategy to design porous nanomaterials with low shrinkage and large SSA,which illustrates promising applications in separation,adsorption,and photoelectric catalysis.
基金supported by the General Research Fund(No.18300920)of Research Grants Council,Hong Kong,Dean’s Research Fund(Nos.04638 and C3688),FLASS,EdUHKMulti-disciplinary Research Capacity Building Scheme(No.04A29)EdUHK,Scientific Research Startup Foundation of Jiangsu Univer-sity(No.22JDG020).
文摘Solar-powered H_(2)O_(2)synthesis from water and oxygen presents a potential strategy in the industrial and environmental domains.However,insufficient light absorption,poor charge separation efficiency,and the same or nearby catalytic sites for the photocatalysts limit the activity of H_(2)O_(2)production.Herein,an ultraviolet-visible-near-infrared light responsive S-scheme heterojunction is created by growing ZnIn_(2)S_(4)(ZIS)subunits firmly on a core of resorcinol-formaldehyde(RF)sphere.The enhanced full-spectrum light response ZIS/RF core-shell structure is evidenced by UV/Vis-NIR diffuse reflectance spectra(DRS).In situ irradiation X-ray photoelectron spectroscopy(XPS)investigation confirms an S-scheme charge transfer mechanism between RF and ZIS.A directional interfacial electric field(IEF)drives the unique spatial separation feature of constructed heterojunction photoexcited carriers and redox centers through the S-scheme transfer pathway with H_(2)O_(2)production.Under solar light irradiation,the optimized ZIS/RF with core-shell structure shows a robust apparent quantum efficiency(AQY)up to 22.5%at 420 nm,1%at 720 nm,and 0.2%at 800 nm.With the key reaction intermediates determined by calculating the average number of transferred electrons and oxygen-reactive species,a possible full-spectrum-light-driven redox mechanism of H_(2)O_(2)synthesis is provided.
基金This project was financially supported by a grant from the NITECH 21st Century COE Program, "World Ceramics Center for Environmental Harmony".
文摘Nano-pore carbon aerogels were prepared by the sol-gel polymerization of resorcinol (1,3-dihydroxybenzene)(C6H4(OH)2) with formaldehyde (HCHO) in a slightly basic aqueous solution, followed by super-critical drying under liquid carbon dioxide as super-critical media and carbonization at 700 ℃ under N2 gas atmosphere. The key of the work is to fabricate carbon aerogels with controllable nano-pore structure, which means extremely high surface area and sharp pore size distribution. Aiming to investigate the effects of preparation conditions on the gelation process, the bulk density, and the physical and chemical structure of the resultant carbon aerogels, the molar ratio of R/C (resorcinol to catalyst) and the amount of distilled water were varied, consequently two different sets of samples, with series of R/C ratio and RF/W (Resorcinol-Formaldehyde to water, or the content of reactant) ratio, were prepared. The result of N2 adsorption/desorption experiment at 77 K shows that the pore sizes decreasing from 11.4 down to 2.2 nm with the increasing of the molar ratio of R/C from 100 to 400, and/or, the pore sizes decreasing from 3.8 down to 1.6 nm with the increasing of reactant content from 0.4 to 0.6.
基金supported by the National Key Research and Development Programme of China(No.2021YFA1202500,H.C.)Foundation of Shenzhen Science,Technology and Innovation Commission(SSTIC)(Nos.20231122110855002,JCYJ20200109141625078,H.C.)+2 种基金National Natural Science Foundation of China(No.12174246,J.L.)Shenzhen Key Laboratory of Interfacial Science and Engineering of Materials(No.ZDSYS20200421111401738,H.C.)Natural Science Funds for Distinguished Young Scholar of Guangdong Province,China(No.2020B151502094,H.C.)。
文摘Formaldehyde(HCHO)as an indoor air pollutant released by new furniture and decorative materials is of great concern.Developing a self-cleaning device to remove HCHO is an ideal way to improve indoor air quality.In this study,a self-cleaning window with a multilayered structure constructed from fluorinedoped tin oxide/bismuth tungstate/resorcinol-formaldehyde resin(FTO/Bi_(2)WO_(6)/RF)has been fabricated,which is capable of degrading HCHO in natural indoor condition.The as-fabricated device could utilize the natural room light and promote the generation and transfer of the photocatalytic carriers in Bi_(2)WO_(6),which subsequently delivers a good catalytic oxygen reduction efficiency in RF to produce hydrogen peroxide(H_(2)O_(2)).The as-synthesized H_(2)O_(2)could further split into hydroxyl radicals(•OH),then oxide the HCHO molecules in the air.The present study demonstrates a novel and efficient strategy to fabricate a transparent multifunctional window for self-cleaning indoor gaseous pollutants,the concept is of great importance to be expanded in a broad range of indoor furniture for in-house air pollution control.
文摘Transition metal dichalcogenide(TMD)materials have recently demonstrated exceptional supercapacitor properties after conversion to a metallic phase,which increases the conductivity of the network.However,freestanding,exfoliated transition metal dichalcogenide films exhibit surface areas far below their theoretical maximum(1.2%),can fail during electrochemical operation due to poor mechanical properties,and often require pyrophoric chemicals to process.On the other hand,pyrolyzed carbon aerogels exhibit extraordinary specific surface areas for double layer capacitance,high conductivity,and a strong mechanical network of covalent chemical bonds.In this paper,we demonstrate the scalable,rapid nanomanufacturing of TMD(MoS2 and WS2)and carbon aerogel composites,favoring liquid-phase exfoliation to avoid pyrophoric chemicals.The aerogel matrix support enhances conductivity of the composite and the synthesis can complete in 30 min.We find that the addition of transition metal dichalcogenides does not impact the structure of the aerogel,which maintains a high specific surface area up to 620 m^(2) g−1 with peak pore radii of 10 nm.While supercapacitor tests of the aerogels yield capacitances around 80 F g^(−1) at the lowest applied currents,the aerogels loaded with TMD’s exhibit volumetric capacitances up to 127% greater than the unloaded aerogels.In addition,the WS2 aerogels show excellent cycling stability with no capacitance loss over 2000 cycles,as well as markedly better rate capability and lower charge transfer resistance compared to their MoS2-loaded counterparts.We hypothesize that these differences in performance stem from differences in contact resistance and in the favorability of ion adsorption on the chalcogenides.
