This work describes the use of TiO_(2)nanotubes-based electrodes(TNT)modified with Cu_(2)O nanostructures and gold nanoparticles for the photoelectroreduction of CO_(2)to produce value-added compounds.A thin layer of ...This work describes the use of TiO_(2)nanotubes-based electrodes(TNT)modified with Cu_(2)O nanostructures and gold nanoparticles for the photoelectroreduction of CO_(2)to produce value-added compounds.A thin layer of polydopamine was used as both an adherent agent and an electron transfer mediator,due to itsπ-conjugated electron system.The highest production yield was achieved using a TNT@PDA/Nc/Au40%electrode,with Faradaic efficiencies of 47.4%(110.5μM cm^(-2))and 27.8%(50.4μM cm^(-2))for methanol and methane,respectively.The performance of the photoelectrodes was shown to be Cu_(2)O facet-dependent,with cubic structures leading to greater conversion of CO_(2)to methanol(43%)and methane(27%),compared to the octahedral morphology,while a higher percentage of metallic gold on the nanostructured Cu_(2)O surface was mainly important for CH4production.Density functional theory(DFT)calculations supported these findings,attributing the superior photoelectrocatalytic performance of the TNT@PDA/Nc/Au40%electrode for CH4generation to the formation of an OCH3intermediate bonded to Au atoms.Studies using isotope-labeling and analysis by gas chromatograph-mass(GC-MS)demonstrated that13CO_(2)was the source for photoelectrocatalytic generation of13CH3OH and13CH313CH2OH.展开更多
Electroconductive hydrogels has been extensively studied in drug delivery systems because they combine the properties of hydogels with the conducting polymers in only one material. In this work, pyrrole was polymerize...Electroconductive hydrogels has been extensively studied in drug delivery systems because they combine the properties of hydogels with the conducting polymers in only one material. In this work, pyrrole was polymerized electrochemically into poly(acrylic acid) hydrogel. This material kept the swelling properties that are characteristic of hydrogels and the electroactivity of the conducting polymers. The hydrogel (with and without the conducting polymer) swelling degree depends on both the ionic strength and pH. As this material is responsive to changes in the electrical potential, pH and ionic strength, the safranin release presented different delivery profiles, in accordance to variations and combinations of these stimuli. The most interesting result was the achievement of the linear safranin release indicating a zero-order kinetics.展开更多
表面组分调控及建立多功能活性位点是提高Pt基催化剂性能的有效途径.通过将Cu可控地锚定在纳米结构PtNi表面(Cu/PtNi)可以精确控制Pt基催化剂表面元素的化学计量比,其中亲氧的非贵金属Ni能加速水的解离,Pt由于具有适中的H吸附能,可有效...表面组分调控及建立多功能活性位点是提高Pt基催化剂性能的有效途径.通过将Cu可控地锚定在纳米结构PtNi表面(Cu/PtNi)可以精确控制Pt基催化剂表面元素的化学计量比,其中亲氧的非贵金属Ni能加速水的解离,Pt由于具有适中的H吸附能,可有效地将游离态的H转换成氢气,Cu由于具有正的H吸附吉布斯自由能(ΔG_(H*)),有助于H_(2)的脱附.其中具有最优组分比例的Cu/PtNi电催化剂在海水中表现出优异的电化学析氢活性和稳定性,在碱性海水中,10 mA cm^(-2)下的过电位为23 mV(在70 mV过电位下,其质量活性是商用Pt/C的5倍).同时,密度泛函理论结果进一步验证了在碱性海水中Pt,Ni和Cu多功能金属活性位点可提高HER的H_(2)O解离、H*吸附和H_(2)脱附的过程.展开更多
基金FAPESP,Brazil(#2023/10027-5,#2014/50945-4,#2020/15230-5,and#2021/000675-4)CNPq,Brazil(#465571/2014-0,#303269/2021-9,and#307837/2014-9)+6 种基金Instituto Serrapilheira(grant number Serra-2211-41925)FAPEMIG,Brazil(#PPM-00831-15)for support of this workCNPq,Brazil(#105944/2022-0)and PROPEUNESP(13/2022)FAPESP(#2019/00463-7,#2018/22845-6,and#2021/08007-0,respectively)for scholarshipsthe National Institute for Alternative Technologies of Detection,Toxicological Evaluation and Removal of Micropollutants and Radioactives(INCT-DATREM)the support of the Research Centre for Greenhouse Gas Innovation(RCGI),hosted by the University of Sao Paulo(USP)and sponsored by FAPESP and Shell Brasilthe strategic support given by ANP,Brazil(Brazilian National Oil,Natural Gas,and Biofuels Agency)through the R&D levy regulation。
文摘This work describes the use of TiO_(2)nanotubes-based electrodes(TNT)modified with Cu_(2)O nanostructures and gold nanoparticles for the photoelectroreduction of CO_(2)to produce value-added compounds.A thin layer of polydopamine was used as both an adherent agent and an electron transfer mediator,due to itsπ-conjugated electron system.The highest production yield was achieved using a TNT@PDA/Nc/Au40%electrode,with Faradaic efficiencies of 47.4%(110.5μM cm^(-2))and 27.8%(50.4μM cm^(-2))for methanol and methane,respectively.The performance of the photoelectrodes was shown to be Cu_(2)O facet-dependent,with cubic structures leading to greater conversion of CO_(2)to methanol(43%)and methane(27%),compared to the octahedral morphology,while a higher percentage of metallic gold on the nanostructured Cu_(2)O surface was mainly important for CH4production.Density functional theory(DFT)calculations supported these findings,attributing the superior photoelectrocatalytic performance of the TNT@PDA/Nc/Au40%electrode for CH4generation to the formation of an OCH3intermediate bonded to Au atoms.Studies using isotope-labeling and analysis by gas chromatograph-mass(GC-MS)demonstrated that13CO_(2)was the source for photoelectrocatalytic generation of13CH3OH and13CH313CH2OH.
基金The authors thank FAPESP(09/53199-3) Instituto Nacional de Bionanalitica for financial support.S.H.T thanks CNPq 141950/2009-9 for the scholarship granted.
文摘Electroconductive hydrogels has been extensively studied in drug delivery systems because they combine the properties of hydogels with the conducting polymers in only one material. In this work, pyrrole was polymerized electrochemically into poly(acrylic acid) hydrogel. This material kept the swelling properties that are characteristic of hydrogels and the electroactivity of the conducting polymers. The hydrogel (with and without the conducting polymer) swelling degree depends on both the ionic strength and pH. As this material is responsive to changes in the electrical potential, pH and ionic strength, the safranin release presented different delivery profiles, in accordance to variations and combinations of these stimuli. The most interesting result was the achievement of the linear safranin release indicating a zero-order kinetics.
基金supported by the National Key Research and Development Program of China(2022YFB3805600,2022YFB3805604,and 2022YFB3806800)the National Natural Science Foundation of China(22293020)+7 种基金the National 111 project(B20002)the Program Fund of Non-Metallic Excellence and Innovation Center for Building Materials(2023TDA1-1)the Program for Changjiang Scholars and Innovative Research Team in University(PCSIRT)(IRT_15R52)Guangdong Basic and Applied Basic Research Foundation(2022A1515010137,2022A1515010504,and 2021A1515111131)Shenzhen Science and Technology Program(GJHZ20210705143204014,JCYJ20210324142010029,and KCXFZ20211020170006010)Hubei Province Key Research and Development Program(2023BAB101)the Fundamental Research Funds for the Central Universities(WUT:2023IVA095 and 2023IV030h)Royal Society for a University Research Fellowship(UF150104,URFR211007)。
文摘表面组分调控及建立多功能活性位点是提高Pt基催化剂性能的有效途径.通过将Cu可控地锚定在纳米结构PtNi表面(Cu/PtNi)可以精确控制Pt基催化剂表面元素的化学计量比,其中亲氧的非贵金属Ni能加速水的解离,Pt由于具有适中的H吸附能,可有效地将游离态的H转换成氢气,Cu由于具有正的H吸附吉布斯自由能(ΔG_(H*)),有助于H_(2)的脱附.其中具有最优组分比例的Cu/PtNi电催化剂在海水中表现出优异的电化学析氢活性和稳定性,在碱性海水中,10 mA cm^(-2)下的过电位为23 mV(在70 mV过电位下,其质量活性是商用Pt/C的5倍).同时,密度泛函理论结果进一步验证了在碱性海水中Pt,Ni和Cu多功能金属活性位点可提高HER的H_(2)O解离、H*吸附和H_(2)脱附的过程.
