Plasmonic metal-semiconductor nano-heterojuncfions （NHJs）, with their superior photocatalytic performance, provide opportunities for the efficient utilization of solar energy. However, scientific significance and te...Plasmonic metal-semiconductor nano-heterojuncfions （NHJs）, with their superior photocatalytic performance, provide opportunities for the efficient utilization of solar energy. However, scientific significance and technical challenges remain in the development of suitable metal-semiconductor NHJ photoelectrodes for new generation flexible optoelectronic devices, which often require complex processing. Herein, we report integrated three-dimensional （3D） NHJ photoelectrodes by conformally coating cadmium sulfide （CdS） nanolayers onto ultrathin nano- porous gold （NPG） films via a facile electrodeposition method. Localized surface plasmon resonance （LSPR） of NPG enhances the electron-hole pair generation and separation. Moreover, the direct contact interface and high conductive framework structure of the NHJs boosts the photogenerated carrier separation and transport. Hence, the NHJs exhibit evidently enhanced photocurrent density and hydrogen evolution rate relative to CdS deposited on either gold （Au） foil or fluorine-doped tin oxide （FTO） at 0 V vs. SCE （saturated calomel electrode） under visible-light irradiation. Moreover, they demonstrate a surprisingly stable photoelectrochemical hydrogen evolution （PEC-HE） activity over 104 s of continuous irradiation.展开更多
Potassium promoted iron–zinc catalysts prepared by co-precipitation method(C–Fe–Zn/K),solvothermal method(S–Fe–Zn/K)and hydrothermal method(H–Fe–Zn/K)could selectively convert CO_2to light olefins,respectively....Potassium promoted iron–zinc catalysts prepared by co-precipitation method(C–Fe–Zn/K),solvothermal method(S–Fe–Zn/K)and hydrothermal method(H–Fe–Zn/K)could selectively convert CO_2to light olefins,respectively.The physicochemical properties of the obtained catalysts were determined by SEM,N_2physisorption,XRD,H_2-TPR,CO_2-TPD and XPS measurements.The results demonstrated that preparation methods had great influences on the morphology,phase structures,reduction and adsorption behavior,and hence the catalytic performance of the catalysts.The samples prepared by hydrothermal and co-precipitation method generated small uniform particles and led to lower specific surface area.In contrast,microspheres with larger specific surface area were formed by self-assembly of nanosheets using solvothermal method.ZnFe_2O_4was the only detectable phase in the fresh C–2Fe–1Zn/K,S–3Fe–1Zn/K and S–2Fe–1Zn/K samples.ZnFe_2O_4and ZnO co-existed with increasing Zncontent in S–1Fe–1Zn/K sample,while ZnO and Fe_2O_3could be observed over H–2Fe–1Zn/K sample.All the used samples contained Fe_3O_4,ZnO and Fe_5C_2.The peak intensity of ZnO was strong in the AR-H–2Fe–1Zn/K sample while it was the lowest in the AR-C–2Fe–1Zn/K sample after reaction.The formation of ZnFe_2O_4increased the interaction between iron and zinc for C–2Fe–1Zn/K and S–Fe–Zn/K samples,causing easier reduction of Fe_2O_3to Fe_3O_4.The surface basicity of the sample prepared by co-precipitation method was much more than that of the other two methods.During CO_2hydrogenation,all the catalysts showed good activity and olefin selectivity.The CO selectivity was increased with increasing Zncontent over S–Fe–Zn/K samples.H–2Fe–1Zn/K catalyst preferred to the production of C_5^+hydrocarbons.CO_2conversion of 54.76%and C_2~=–C_4~=contents of 57.38%were obtained on C–2Fe–1Zn/K sample,respectively.展开更多
In this work, a new photocatalyts In(0.1),Cu(x)-Zn S(x = 0.01, 0.03, 0.05) is successfully synthesized using simple hydrothermal method. The physical and chemical properties of the In and Cu co-doped Zn S photocatalys...In this work, a new photocatalyts In(0.1),Cu(x)-Zn S(x = 0.01, 0.03, 0.05) is successfully synthesized using simple hydrothermal method. The physical and chemical properties of the In and Cu co-doped Zn S photocatalyst were characterized by X-ray diffraction(XRD), field emission scanning electron microscopy(FESEM), diffuse reflectance UV-visible spectroscopy(DR UV-visible) and photoluminescence spectroscopy(PL). The photocatalytic activity of the as-prepared In and Cu co-doped Zn S for hydrogen production from water with Na_2SO_3 and Na_2S as sacrificial agent under visible light irradiation(λ ≥ 425 nm) was investigated. The presence of co-dopants facilitated the separation of electron-hole as well as increases the visible light absorption. The absorption edge of the co-doped Zn S photocatalyst shifted to longer wavelength as the amount of Cu increases. This indicates that the absorption properties depended on the amount of Cu doped. The photocatalytic activity of single doped In(0.1)-Zn S was significantly enhanced by co-doping with Cu under visible light irradiation. The highest photocatalytic activity was observed on In(0.1),Cu(0.03)-Zn S with the hydrogen production rate of 131.32 μmol/h under visible light irradiation.This is almost 8 times higher than single doped In(0.1)-ZnS.展开更多
A series of CoxMn0.06/SiO2 catalysts were prepared by an impregnation method for catalytic hydrogenation of CO to Light Hydrocarbons(LHCs).The catalysts were characterized by XRD,SEM,N2 adsorption and NH3-TPD techniqu...A series of CoxMn0.06/SiO2 catalysts were prepared by an impregnation method for catalytic hydrogenation of CO to Light Hydrocarbons(LHCs).The catalysts were characterized by XRD,SEM,N2 adsorption and NH3-TPD techniques.Catalyst activities were evaluated in a high-pressure micro reactor.The results show that the performance of the catalysts was significantly affected by the amount of Co loaded onto the substrate.The activity of the Co0.10Mn0.06/SiO2 catalyst was stable with time-on-stream.The CO conversion and LHCs selectivity were 95.3% and 98.1%,respectively,for this catalyst at 400 °C.展开更多
Biomimetics provides us a new perspective to understand complex biological process and strategy to fabricate functional materials. However,a great challenge still remains to design and fabricate biomimetic materials u...Biomimetics provides us a new perspective to understand complex biological process and strategy to fabricate functional materials. However,a great challenge still remains to design and fabricate biomimetic materials using a facile but effective method. Here, we develop a biomimetic light harvesting architecture based on one-step co-assembly of amphiphilic amino acid and porphyrin. Amphiphilic amino acid can self-assemble into nanofibers via π-stacking and hydrogen binding interactions. Negatively charged porphyrin adsorbs on the surface of the assembled nanofibers through electrostatic force, and the nanofibers further organize into porous urchin-like microspheres induced presumably by hydrophobic interaction. The assembled amphiphilic amino acid nanofibers work as a template to tune the organization of porphyrin with an architecture principle analogous to natural light harvesting complex. The co-assembled microspheres exhibit enhanced light capture due to the light reflection in the porous structure. Reaction center(platinum nanoparticles) can be effectively coupled with the light harvesting microspheres via photoreduction. After visible light illumination, hydrogen evolution occurs on the hybrid microspheres.展开更多
Directly making light olefins via CO hydrogenation is a promising process toobtain a non-petroleum based supply of alkenes. Limited by the ASF distribution function ofFischer-Tropsch synthesis, the yield of light olef...Directly making light olefins via CO hydrogenation is a promising process toobtain a non-petroleum based supply of alkenes. Limited by the ASF distribution function ofFischer-Tropsch synthesis, the yield of light olefins (C_2-C_4) can not reach the desired levels,which is a great challenge to overcome. Beginning with a brief introduction of F-T synthesis, thispaper provides a review of current research, including thermodynamic analysis, the ASF distributionfunction, the reaction performance of CO hydrogenation and slurry reactor studies. The problemscurrently faced by this research area are presented at the end of the article.展开更多
A novel Sr2CulnO3S oxysulfide p-type semiconductor photocatalyst has been prepared by solid state reaction method and it exhibits intriguing visible light absorption properties with a bandgap of 2.3 eV. The p-type sem...A novel Sr2CulnO3S oxysulfide p-type semiconductor photocatalyst has been prepared by solid state reaction method and it exhibits intriguing visible light absorption properties with a bandgap of 2.3 eV. The p-type semiconductor character of the synthesized Sr2CuInO3 S was confirmed by Hall efficient measurement and Mott-Schottky plot analysis. First-principles density functional theory calculations （DFT） and electrochem ical measurements were performed to elucidate the electronic structure and the energy band locations. It was found that the as-synthesized Sr2CuInO3S photocatalyst has appreciate conduction and valence band positions for hydrogen and oxygen evolution, respectively. Photocat alytic hydrogen production experiments under a visible light irradiation （A〉420 nm） were carried out by loading different metal and metal-like cocatalysts on Sr2CuInO3S and Rh was found to be the best one among the tested ones.展开更多
The tetramethylammonium salts of diplatinum(II) complexes composed of mono-lacunary Keggin-type silico and germanotungstates, [(CH<sub>3</sub>)<sub>4</sub>N]<sub>4</sub>[α-SiW<s...The tetramethylammonium salts of diplatinum(II) complexes composed of mono-lacunary Keggin-type silico and germanotungstates, [(CH<sub>3</sub>)<sub>4</sub>N]<sub>4</sub>[α-SiW<sub>11</sub>O<sub>39</sub>{cis-Pt(NH<sub>3</sub>)<sub>2</sub>}<sub>2</sub>]·13H<sub>2</sub>O (TMA-Si-Pt) and [(CH<sub>3</sub>)<sub>4</sub>N]<sub>4</sub>[α-GeW<sub>11</sub>O<sub>39</sub>{cis-Pt(NH<sub>3</sub>)<sub>2</sub>}<sub>2</sub>]·11H<sub>2</sub>O (TMA-Ge-Pt), were synthesized and crystallized. Single crystals of a tetramethylammonium salt of Keggin-type diplatinum(II)-coordinated phosphotungstate [(CH<sub>3</sub>)<sub>4</sub>N]<sub>3</sub>[α-PW<sub>11</sub>O<sub>39</sub>{cis-Pt(NH<sub>3</sub>)<sub>2</sub>}<sub>2</sub>]×10H<sub>2</sub>O (TMA-P-Pt) were also obtained. The X-ray structural analyses revealed that the two cis-platinum(II) moieties, [cis-Pt(NH<sub>3</sub>)<sub>2</sub>]<sup>2+</sup>, were each coordinated to two oxygen atoms in a mono-vacant site of [XW<sub>11</sub>O<sub>39</sub>]<sup>(12-n)-</sup> (X<sup>n+</sup> = Si<sup>4+</sup>, Ge<sup>4+</sup>, P<sup>5+</sup>). FTIR spectra of TMA-Si-Pt and TMA-Ge-Pt also suggested that the two platinum(II) moieties were coordinated to the vacant site of [SiW<sub>11</sub>O<sub>39</sub>]<sup>8-</sup> and [GeW<sub>11</sub>O<sub>39</sub>]<sup>8-</sup>. The <sup>1</sup>H NMR spectra in DMSO-d<sub>6</sub> of TMA-Si-Pt and TMA-Ge-Pt showed signals assigned to the two sets of NH<sub>3</sub> ligands coordinated to the platinum sites. These three platinum compounds showed hydrogen evolution from aqueous triethanolamine solution under visible light irradiation (λ ≥ 400 nm) in the presence of eosin Y, α-Keggin mono-aluminum-substituted silicotungstate, and titanium dioxide. The catalytic activities were influenced by the central atoms, and TMA-P-Pt showed the highest activities among the three platinum compounds.展开更多
基金This work was financially supported by the National Natural Science Foundation of China （No. 51671145）, the National Thousand Young Talents Program of China, the Tianjin Municipal Education Commission, the Tianjin Munidpal Science and Technology Commission （No. 16JCYBJC17000） and the Fundamental Research Funds of Tianjin University of Technology. We would like to thank Dr. Anna Carlsson from FEI Company for her assistance with the atomic-resolution structure and EELS analyses, and Y. D. also acknowledges useful discussions and experimental assistance from Dr. Yajun Gao, Dr. Rongyue Wang, Dr. Chuancheng Jia, Xuanxuan Bi, and Junli Liu.
文摘Plasmonic metal-semiconductor nano-heterojuncfions （NHJs）, with their superior photocatalytic performance, provide opportunities for the efficient utilization of solar energy. However, scientific significance and technical challenges remain in the development of suitable metal-semiconductor NHJ photoelectrodes for new generation flexible optoelectronic devices, which often require complex processing. Herein, we report integrated three-dimensional （3D） NHJ photoelectrodes by conformally coating cadmium sulfide （CdS） nanolayers onto ultrathin nano- porous gold （NPG） films via a facile electrodeposition method. Localized surface plasmon resonance （LSPR） of NPG enhances the electron-hole pair generation and separation. Moreover, the direct contact interface and high conductive framework structure of the NHJs boosts the photogenerated carrier separation and transport. Hence, the NHJs exhibit evidently enhanced photocurrent density and hydrogen evolution rate relative to CdS deposited on either gold （Au） foil or fluorine-doped tin oxide （FTO） at 0 V vs. SCE （saturated calomel electrode） under visible-light irradiation. Moreover, they demonstrate a surprisingly stable photoelectrochemical hydrogen evolution （PEC-HE） activity over 104 s of continuous irradiation.
基金Supports by the National Natural Science Foundation of China(21666030,21366025)National First-rate Discipline Construction Project of Ningxia(NXYLXK2017A04)
文摘Potassium promoted iron–zinc catalysts prepared by co-precipitation method(C–Fe–Zn/K),solvothermal method(S–Fe–Zn/K)and hydrothermal method(H–Fe–Zn/K)could selectively convert CO_2to light olefins,respectively.The physicochemical properties of the obtained catalysts were determined by SEM,N_2physisorption,XRD,H_2-TPR,CO_2-TPD and XPS measurements.The results demonstrated that preparation methods had great influences on the morphology,phase structures,reduction and adsorption behavior,and hence the catalytic performance of the catalysts.The samples prepared by hydrothermal and co-precipitation method generated small uniform particles and led to lower specific surface area.In contrast,microspheres with larger specific surface area were formed by self-assembly of nanosheets using solvothermal method.ZnFe_2O_4was the only detectable phase in the fresh C–2Fe–1Zn/K,S–3Fe–1Zn/K and S–2Fe–1Zn/K samples.ZnFe_2O_4and ZnO co-existed with increasing Zncontent in S–1Fe–1Zn/K sample,while ZnO and Fe_2O_3could be observed over H–2Fe–1Zn/K sample.All the used samples contained Fe_3O_4,ZnO and Fe_5C_2.The peak intensity of ZnO was strong in the AR-H–2Fe–1Zn/K sample while it was the lowest in the AR-C–2Fe–1Zn/K sample after reaction.The formation of ZnFe_2O_4increased the interaction between iron and zinc for C–2Fe–1Zn/K and S–Fe–Zn/K samples,causing easier reduction of Fe_2O_3to Fe_3O_4.The surface basicity of the sample prepared by co-precipitation method was much more than that of the other two methods.During CO_2hydrogenation,all the catalysts showed good activity and olefin selectivity.The CO selectivity was increased with increasing Zncontent over S–Fe–Zn/K samples.H–2Fe–1Zn/K catalyst preferred to the production of C_5^+hydrocarbons.CO_2conversion of 54.76%and C_2~=–C_4~=contents of 57.38%were obtained on C–2Fe–1Zn/K sample,respectively.
基金Financial support from the Ministry of Science,Technology and Innovation of Malaysia(MOSTI)by the National Science Fellowship(NSF)
文摘In this work, a new photocatalyts In(0.1),Cu(x)-Zn S(x = 0.01, 0.03, 0.05) is successfully synthesized using simple hydrothermal method. The physical and chemical properties of the In and Cu co-doped Zn S photocatalyst were characterized by X-ray diffraction(XRD), field emission scanning electron microscopy(FESEM), diffuse reflectance UV-visible spectroscopy(DR UV-visible) and photoluminescence spectroscopy(PL). The photocatalytic activity of the as-prepared In and Cu co-doped Zn S for hydrogen production from water with Na_2SO_3 and Na_2S as sacrificial agent under visible light irradiation(λ ≥ 425 nm) was investigated. The presence of co-dopants facilitated the separation of electron-hole as well as increases the visible light absorption. The absorption edge of the co-doped Zn S photocatalyst shifted to longer wavelength as the amount of Cu increases. This indicates that the absorption properties depended on the amount of Cu doped. The photocatalytic activity of single doped In(0.1)-Zn S was significantly enhanced by co-doping with Cu under visible light irradiation. The highest photocatalytic activity was observed on In(0.1),Cu(0.03)-Zn S with the hydrogen production rate of 131.32 μmol/h under visible light irradiation.This is almost 8 times higher than single doped In(0.1)-ZnS.
基金the National Natural Science Foundation of China (No.50921002)the National Basic Research Program of China (No.2005CB221204-G) the Program of the Universities in Jiangsu Province for Development of High-Tech Industries (No.JHB05-33)
文摘A series of CoxMn0.06/SiO2 catalysts were prepared by an impregnation method for catalytic hydrogenation of CO to Light Hydrocarbons(LHCs).The catalysts were characterized by XRD,SEM,N2 adsorption and NH3-TPD techniques.Catalyst activities were evaluated in a high-pressure micro reactor.The results show that the performance of the catalysts was significantly affected by the amount of Co loaded onto the substrate.The activity of the Co0.10Mn0.06/SiO2 catalyst was stable with time-on-stream.The CO conversion and LHCs selectivity were 95.3% and 98.1%,respectively,for this catalyst at 400 °C.
基金financial support from the National Natural Science Foundation of China(Project Nos.21522307,21473208,91434103 and 21473153)the Talent Fund of the Recruitment Program of Global Youth Expertsthe Chinese Academy of Sciences
文摘Biomimetics provides us a new perspective to understand complex biological process and strategy to fabricate functional materials. However,a great challenge still remains to design and fabricate biomimetic materials using a facile but effective method. Here, we develop a biomimetic light harvesting architecture based on one-step co-assembly of amphiphilic amino acid and porphyrin. Amphiphilic amino acid can self-assemble into nanofibers via π-stacking and hydrogen binding interactions. Negatively charged porphyrin adsorbs on the surface of the assembled nanofibers through electrostatic force, and the nanofibers further organize into porous urchin-like microspheres induced presumably by hydrophobic interaction. The assembled amphiphilic amino acid nanofibers work as a template to tune the organization of porphyrin with an architecture principle analogous to natural light harvesting complex. The co-assembled microspheres exhibit enhanced light capture due to the light reflection in the porous structure. Reaction center(platinum nanoparticles) can be effectively coupled with the light harvesting microspheres via photoreduction. After visible light illumination, hydrogen evolution occurs on the hybrid microspheres.
文摘Directly making light olefins via CO hydrogenation is a promising process toobtain a non-petroleum based supply of alkenes. Limited by the ASF distribution function ofFischer-Tropsch synthesis, the yield of light olefins (C_2-C_4) can not reach the desired levels,which is a great challenge to overcome. Beginning with a brief introduction of F-T synthesis, thispaper provides a review of current research, including thermodynamic analysis, the ASF distributionfunction, the reaction performance of CO hydrogenation and slurry reactor studies. The problemscurrently faced by this research area are presented at the end of the article.
基金financially supported by the National Natural Science Foundation of China(Grant No.21090341 and 21361140346)the National Basic Research Program(973 Program)of the Ministry of Science and Technology of China(Grant No.2014CB239401)
文摘A novel Sr2CulnO3S oxysulfide p-type semiconductor photocatalyst has been prepared by solid state reaction method and it exhibits intriguing visible light absorption properties with a bandgap of 2.3 eV. The p-type semiconductor character of the synthesized Sr2CuInO3 S was confirmed by Hall efficient measurement and Mott-Schottky plot analysis. First-principles density functional theory calculations （DFT） and electrochem ical measurements were performed to elucidate the electronic structure and the energy band locations. It was found that the as-synthesized Sr2CuInO3S photocatalyst has appreciate conduction and valence band positions for hydrogen and oxygen evolution, respectively. Photocat alytic hydrogen production experiments under a visible light irradiation （A〉420 nm） were carried out by loading different metal and metal-like cocatalysts on Sr2CuInO3S and Rh was found to be the best one among the tested ones.
文摘The tetramethylammonium salts of diplatinum(II) complexes composed of mono-lacunary Keggin-type silico and germanotungstates, [(CH<sub>3</sub>)<sub>4</sub>N]<sub>4</sub>[α-SiW<sub>11</sub>O<sub>39</sub>{cis-Pt(NH<sub>3</sub>)<sub>2</sub>}<sub>2</sub>]·13H<sub>2</sub>O (TMA-Si-Pt) and [(CH<sub>3</sub>)<sub>4</sub>N]<sub>4</sub>[α-GeW<sub>11</sub>O<sub>39</sub>{cis-Pt(NH<sub>3</sub>)<sub>2</sub>}<sub>2</sub>]·11H<sub>2</sub>O (TMA-Ge-Pt), were synthesized and crystallized. Single crystals of a tetramethylammonium salt of Keggin-type diplatinum(II)-coordinated phosphotungstate [(CH<sub>3</sub>)<sub>4</sub>N]<sub>3</sub>[α-PW<sub>11</sub>O<sub>39</sub>{cis-Pt(NH<sub>3</sub>)<sub>2</sub>}<sub>2</sub>]×10H<sub>2</sub>O (TMA-P-Pt) were also obtained. The X-ray structural analyses revealed that the two cis-platinum(II) moieties, [cis-Pt(NH<sub>3</sub>)<sub>2</sub>]<sup>2+</sup>, were each coordinated to two oxygen atoms in a mono-vacant site of [XW<sub>11</sub>O<sub>39</sub>]<sup>(12-n)-</sup> (X<sup>n+</sup> = Si<sup>4+</sup>, Ge<sup>4+</sup>, P<sup>5+</sup>). FTIR spectra of TMA-Si-Pt and TMA-Ge-Pt also suggested that the two platinum(II) moieties were coordinated to the vacant site of [SiW<sub>11</sub>O<sub>39</sub>]<sup>8-</sup> and [GeW<sub>11</sub>O<sub>39</sub>]<sup>8-</sup>. The <sup>1</sup>H NMR spectra in DMSO-d<sub>6</sub> of TMA-Si-Pt and TMA-Ge-Pt showed signals assigned to the two sets of NH<sub>3</sub> ligands coordinated to the platinum sites. These three platinum compounds showed hydrogen evolution from aqueous triethanolamine solution under visible light irradiation (λ ≥ 400 nm) in the presence of eosin Y, α-Keggin mono-aluminum-substituted silicotungstate, and titanium dioxide. The catalytic activities were influenced by the central atoms, and TMA-P-Pt showed the highest activities among the three platinum compounds.
