The steel industry produces many byproducts, requiring extensive land for storage and causing significant environmental contamination. Industrial effluents discharged into water bodies negatively impact both aquatic e...The steel industry produces many byproducts, requiring extensive land for storage and causing significant environmental contamination. Industrial effluents discharged into water bodies negatively impact both aquatic ecosystems and human health. To solve this problem, this study synthesized a composite of titanium dioxide (TiO2) and steel slag nanocomposites (SSNC) at a 1:2 mass ratio to create a robust photocatalyst for the treatment of synthetic wastewater. The efficacy of this catalyst in degrading various dye pollutants, including methylene blue (MB), was tested under simulated solar light conditions. Comprehensive analyses were conducted to assess the physical and chemical characteristics, crystalline structure, energy gap, and point of zero charge of the composite. The TiO2-SSNC composite catalyst exhibited excellent stability, with a point of zero charge at 8.342 and an energy gap of 2.4 eV. The degradation process conformed to pseudo-first-order kinetics. Optimization of operational parameters was achieved through the response surface methodology. Reusability tests demonstrated that the TiO2-SSNC composite catalyst effectively degraded up to 93.41% of MB in the suspended mode and 92.03% in the coated mode after five cycles. Additionally, the degradation efficiencies for various dyes were significant, highlighting the potential of the composite for broad applications in industrial wastewater treatment. This study also explored the degradation mechanisms and identified byproducts, establishing a pathway for contaminant breakdown. The cost-benefit analysis revealed a total cost of 0.842 8 USD per cubic meter for each treatment activity, indicating low operational and production costs. These findings underscore the promise of the TiO2-SSNC composite as a cost-effective and efficient alternative for wastewater purification.展开更多
Synergistic interplays involving multiple active centers originating from TiO2 nanotube layers(TNT)and ruthenium(Ru)species comprising of both single atoms(SAs)and nanoparticles(NPs)augment the alkaline hydrogen evolu...Synergistic interplays involving multiple active centers originating from TiO2 nanotube layers(TNT)and ruthenium(Ru)species comprising of both single atoms(SAs)and nanoparticles(NPs)augment the alkaline hydrogen evolution reaction(HER)by enhancing Volmer kinetics from rapid water dissociation and improving Tafel kinetics from efficient H*desorption.Atomic layer deposition of Ru with 50 process cycles results in a mixture of Ru SAs and 2.8-0.4 nm NPs present on TNT layers,and it emerges with the highest HER activity among all the electrodes synthesized.A detailed study of the Ti and Ru species using different high-resolution techniques confirmed the presence of Ti^(3+)states and the coexistence of Ru SAs and NPs.With insights from literature,the role of Ti^(3+),appropriate work functions of TNT layers and Ru,and the synergistic effect of Ru SAs and Ru NPs in improving the performance of alkaline HER were elaborated and justified.The aforementioned characteristics led to a remarkable performance by having 9mV onset potentials and 33 mV dec^(-1) of Tafel slopes and a higher turnover frequency of 1.72 H2 s^(-1) at 30 mV.Besides,a notable stability from 28 h staircase chronopotentiometric measurements for TNT@Ru surpasses TNT@Pt in comparison.展开更多
Two-dimensional (2D) ultrathin MoS2-modified black Ti^3+-TiO2 nanotubes were fabricated using an electrospinning-hydrothermal treatment-reduction method.Bare TiO2 nanotubes were fabricated via electrospinning.Then,2D ...Two-dimensional (2D) ultrathin MoS2-modified black Ti^3+-TiO2 nanotubes were fabricated using an electrospinning-hydrothermal treatment-reduction method.Bare TiO2 nanotubes were fabricated via electrospinning.Then,2D MoS2 lamellae were grown on the surface of the nanotubes and Ti^3+/Ov ions were introduced by reduction.The photocatalytic performance of the 2D MoS2/Ti^3+-TiO2 nanotubes was^15 times better than that of TiO2.The HER enhancement of the MoS2/Ti^3+-TiO2 nanotubes can be attributed to the Pt-like behavior of 2D MoS2 and the presence of Ti^3+-ions,which facilitated the quick diffusion of the photogenerated electrons to water,reducing the H2 activation barrier.The presence of Ov ions in the nanotubes and their hollow structure increased their solar utilization.展开更多
Low‐temperature selective catalytic reduction(SCR)of NO with NH3 was tested over Ho‐doped Mn–Ce/TiO2 catalysts prepared by the impregnation method.The obtained catalysts with different Ho doping ratios were charact...Low‐temperature selective catalytic reduction(SCR)of NO with NH3 was tested over Ho‐doped Mn–Ce/TiO2 catalysts prepared by the impregnation method.The obtained catalysts with different Ho doping ratios were characterized by Brunauer‐Emmett‐Teller(BET),X‐ray diffraction(XRD),temperature‐programmed reduction(H2‐TPR),temperature‐programmed desorption of NH3(NH3‐TPD),X‐ray photoelectron spectroscopy(XPS),and scanning electron microscopy(SEM).The catalytic activities were tested on a fixed bed.Their results indicated that the proper doping amount of Ho could effectively improve the low‐temperature denitrification performance and the SO2 resistance of Mn–Ce/TiO2 catalyst.The catalyst with Ho/Ti of 0.1 presented excellent catalytic activity,with a conversion of more than 90%in the temperature window of 140–220°C.The characterization results showed that the improved SCR activity of the Mn–Ce/TiO2 catalyst caused by Ho doping was due to the increase of the specific surface area,higher concentration of chemisorbed oxygen,higher surface Mn4+/Mn3+ratio,and higher acidity.The SO2 resistance test showed that the deactivating influence of SO2 on the catalyst was irreversible.The XRD and XPS results showed that the main reason for the catalyst deactivation was sulfates that had formed on the catalyst surface and that Ho doping could inhibit the sulfation to some extent.展开更多
A series of phosphorus-modified titanium dioxide samples with varying P/Ti atomic ratio were conveniently prepared via a conventional solgel route. The effects of phosphorus content and calcination temperature on the ...A series of phosphorus-modified titanium dioxide samples with varying P/Ti atomic ratio were conveniently prepared via a conventional solgel route. The effects of phosphorus content and calcination temperature on the crystalline structure, grain growth, surface area, and the photocatalytic activity of P-modified TiO2 were investigated. The XRD results showed that P species slow down the particle growth of anatase and increase the anatase-to-rutile phase transformation temperature to more than 900°C. Kinetic studies on the P-modified TiO2 to degraded 4-chlorophenol had found that the TP5500 prepared by adopting a P/Ti atomic ratio equal to 0.05 and calcined at 500°C had an apparent rate constant equal to 0.0075 min 1, which is superior to the performance of a commercial photocatalyst Degussa P25 Kapp = 0.0045 min 1 and of unmodified TiO2 （TP0500） Kapp = 0.0022 min 1. From HPLC analyses, various hydroxylated intermediates formed during oxidation had been identified, including hydroquinone （HQ）, benzoquinone （BQ） and （4CC） 4-chlorocatechol as main products. Phytotoxicity was assessed before and after irradiation against seed germination of tomato （Lycopersicon esculentum） whereas acute toxicity was assessed by using Folsomia candida as the test organism. Intermediates products were all less toxic than 4-chlorophenol and a significant removal of the overall toxicity was accomplished展开更多
Adding a small amount of nanocrystalline TiO2@C （TiO2 supported on nano- porous carbon） composite dramatically decreases the operating temperatures and improves the reaction kinetics for hydrogen storage in NaAlH4. ...Adding a small amount of nanocrystalline TiO2@C （TiO2 supported on nano- porous carbon） composite dramatically decreases the operating temperatures and improves the reaction kinetics for hydrogen storage in NaAlH4. The nano- crystalline TiO2@C composite synthesized at 900 ℃ （referred as TiO2@C-900） exhibits superior catalytic activity to other catalyst-containing samples. The onset dehydrogenation temperature of the TiO2@C-900-containing sample is lowered to 90 ℃; this is 65 ℃ lower than that of the pristine sample. The dehydrogenated sample is completely hydrogenated at 115 ℃ and 100 bar of hydrogen pressure with a hydrogen capacity of 4.5 wt.%. Structural analyses reveal that the Ti undergoes a reduction process of Ti^4＋→Ti^3＋→Ti^2＋→Ti during the ball milling and heating processes, and further converts to Ti hydrides or forms Ti-Al species after rehydrogenation. The catalytic activities of Ti-based catalytic species decrease in the order Al-Ti-species 〉 TiH0.71 〉 TiH2 〉 TiO2. This understanding guides further improvement in hydrogen storage properties of metal alanates using nanocrvstalline transition metal-based additives.展开更多
The adsorption equilibrium of a fluoride solution on 1-2 mm granular activated alumina modified by Fe2(SO4)3 solution was investigated.The experiments were conducted using a wide range of initial fluoride concentratio...The adsorption equilibrium of a fluoride solution on 1-2 mm granular activated alumina modified by Fe2(SO4)3 solution was investigated.The experiments were conducted using a wide range of initial fluoride concentrations(0.5 to 180 mg·L-1 at pH～7.0) and an adsorbent dose of 1.0 g·L-1.The application of Langmuir and Freundlich adsorption isotherm models(linear and nonlinear forms) generally showed that a single Langmuir or Freundlich equation cannot fit the entire concentration gap.Experimental data on low equilibrium concentrations(0.1 to 5.0 mg·L-1) was in line with both Langmuir and Freundlich isotherm models,whereas that of high equilibrium concentrations(5.0 to 150 mg·L-1) was more in line with the Freundlich isotherm model.A new LangmuirFreundlich function was used for the entire concentration gap,as well as for low and high concentrations.展开更多
Carbon and few-layer MoS2 nanosheets co- modified TiO2 nanocomposites （defined as MoS2-C@TiO2） were prepared through a facile one-step pyrolysis reaction technique. In this unique nanostructure, the TiO2 nanosh- eet...Carbon and few-layer MoS2 nanosheets co- modified TiO2 nanocomposites （defined as MoS2-C@TiO2） were prepared through a facile one-step pyrolysis reaction technique. In this unique nanostructure, the TiO2 nanosh- eets with stable structure serve as the backbones, and carbon coating and few-layer MoS2 tightly adhere onto the surface of the TiO2. It needs to be pointed out that the carbon coating improves the overall electronic conductivity and the few-layer MoS2 facilitates the diffusion of lithium ions and offers more active sites for lithium-ion storage. As a result, when evaluated as lithium-ion battery anodes, the MoS2-C@TiO2 nanocomposites exhibit markedly enhanced lithium storage capability compared with pure TiO2. A high specific capacity of 180 mA.h.g-1 has been achieved during the preliminary cycles, and the specific capacity can maintain 160 mA.h.g-1 at a high current density of 1C （1C=167 mA.g-1） even after 300 discharge/ charge cycles, indicating the great potential of the MoS2- C@TiO2 on energy storage.展开更多
TiO2 nanotube arrays were prepared by means of an electrochemical anodization technique in an organic electrolyte solution doped with polyvinyl pyrrolidone (PVP) and were subsequently modified with phosphomolybdic aci...TiO2 nanotube arrays were prepared by means of an electrochemical anodization technique in an organic electrolyte solution doped with polyvinyl pyrrolidone (PVP) and were subsequently modified with phosphomolybdic acid (PMoA) to obtain PMoA/TiO2 nanotube arrays. The microstructure and photochromic properties were investigated via X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet-visible spectroscopy (UV-vis), and X-ray photoelectron spectroscopy (XPS). The results indicated that the Keggin structure of PMoA and the nanotube structure of TiO2 were not destroyed, and there was a strong degree of interaction between PMoA and TiO2 at the biphasic interface with lattice interlacing during the compositing process. The XPS results further indicated that there was a change in the chemical microenvironment during the formation process of the composite, and a new charge transfer bridge was formed through the Mo-O-Ti bond. Under visible light irradiation, the colorless PMoA/TiO2 nanotube array quickly turned blue and exhibited a photochromic response together with reversible photochromism in the presence of H2O2. After visible light irradiation for 60s, the appearance of Mo^5+ species in the XPS spectra indicated a photoreduction process in accordance with a photoinduced electron transfer mechanism.展开更多
In this study,CuBi2O4 photocathodes were prepared using a simple electrodeposition method for photoelectrochemical(PEC)hydrogen production.The prepared photocathodes were modified with amorphous TiO2 and a Pt co‐cata...In this study,CuBi2O4 photocathodes were prepared using a simple electrodeposition method for photoelectrochemical(PEC)hydrogen production.The prepared photocathodes were modified with amorphous TiO2 and a Pt co‐catalyst,which resulted in the formation of CuBi2O4/TiO2 p‐n heterojunctions,and enhanced the activities of the as‐prepared photocathodes.The novel Pt/TiO2/CuBi2O4 photocathode exhibited a photocurrent of 0.35 mA/cm2 at 0.60 V vs.Reversible Hydrogen Electrode(RHE),which was nearly twice that of the Pt/CuBi2O4 photocathode.The present study provides a facile method for increasing the efficiency of photocathodes and provides meaningful guidance for the preparation of high‐performance CuBi2O4 photocathodes.展开更多
As the oxygen redox ability shows great effects on the catalytic performances of ceria-zirconia based materials,many strategies have been utilized to improve the oxygen storage capacity.Here in this study,we report a ...As the oxygen redox ability shows great effects on the catalytic performances of ceria-zirconia based materials,many strategies have been utilized to improve the oxygen storage capacity.Here in this study,we report a simple and facile approach to prepare a SO_(4)^(2-)-modified La,Y-doped ceria-zirconia material(SO/CZLY-f)with high oxygen storage capacity.Due to the additional redox process between SO_(4)^(2-)and S^(2-),oxygen storage capacity of SO/CZLY-f(745.3μmol O_(2)/g)is about 1.6 times higher than that of La,Ydoped ceria-zirconia material without SO_(4)^(2-)modification.Moreover,the catalytic activities and stability of the corresponding Pd-only three-way catalyst were measured.Compared to that of Pd@CZLY-f,the operation window of CO,full conversion temperature of HC and NO over Pd@SO/CZLY-f are obviously widened and lowered,respectively.After aging treatment at 1100℃for 4 h,the superiority of aged Pdloading composite is still maintained.展开更多
基金supported by the Department of Chemical and Petrochemical Engineering,Egypt-Japan University of Science and Technology.
文摘The steel industry produces many byproducts, requiring extensive land for storage and causing significant environmental contamination. Industrial effluents discharged into water bodies negatively impact both aquatic ecosystems and human health. To solve this problem, this study synthesized a composite of titanium dioxide (TiO2) and steel slag nanocomposites (SSNC) at a 1:2 mass ratio to create a robust photocatalyst for the treatment of synthetic wastewater. The efficacy of this catalyst in degrading various dye pollutants, including methylene blue (MB), was tested under simulated solar light conditions. Comprehensive analyses were conducted to assess the physical and chemical characteristics, crystalline structure, energy gap, and point of zero charge of the composite. The TiO2-SSNC composite catalyst exhibited excellent stability, with a point of zero charge at 8.342 and an energy gap of 2.4 eV. The degradation process conformed to pseudo-first-order kinetics. Optimization of operational parameters was achieved through the response surface methodology. Reusability tests demonstrated that the TiO2-SSNC composite catalyst effectively degraded up to 93.41% of MB in the suspended mode and 92.03% in the coated mode after five cycles. Additionally, the degradation efficiencies for various dyes were significant, highlighting the potential of the composite for broad applications in industrial wastewater treatment. This study also explored the degradation mechanisms and identified byproducts, establishing a pathway for contaminant breakdown. The cost-benefit analysis revealed a total cost of 0.842 8 USD per cubic meter for each treatment activity, indicating low operational and production costs. These findings underscore the promise of the TiO2-SSNC composite as a cost-effective and efficient alternative for wastewater purification.
基金support from the European Union Horizon 2020 program(project HERMES,nr.952184)the Ministry of Education,Youth and Sports of the Czech Republic for supporting CEMNAT(LM2023037)+1 种基金Czech-NanoLab(LM2023051)infrastructures for providing ALD,SEM,EDX,XPS,TEM,and XRDCzech Science Foundation(project 23-08019X,EXPRO).
文摘Synergistic interplays involving multiple active centers originating from TiO2 nanotube layers(TNT)and ruthenium(Ru)species comprising of both single atoms(SAs)and nanoparticles(NPs)augment the alkaline hydrogen evolution reaction(HER)by enhancing Volmer kinetics from rapid water dissociation and improving Tafel kinetics from efficient H*desorption.Atomic layer deposition of Ru with 50 process cycles results in a mixture of Ru SAs and 2.8-0.4 nm NPs present on TNT layers,and it emerges with the highest HER activity among all the electrodes synthesized.A detailed study of the Ti and Ru species using different high-resolution techniques confirmed the presence of Ti^(3+)states and the coexistence of Ru SAs and NPs.With insights from literature,the role of Ti^(3+),appropriate work functions of TNT layers and Ru,and the synergistic effect of Ru SAs and Ru NPs in improving the performance of alkaline HER were elaborated and justified.The aforementioned characteristics led to a remarkable performance by having 9mV onset potentials and 33 mV dec^(-1) of Tafel slopes and a higher turnover frequency of 1.72 H2 s^(-1) at 30 mV.Besides,a notable stability from 28 h staircase chronopotentiometric measurements for TNT@Ru surpasses TNT@Pt in comparison.
基金supported by the National Natural Science Foundation of China(Grant Nos.51672249,51802282,and 11804301)the Zhejiang Provincial Natural Science Foundation of China(Grant Nos.LQ17F040004 and LY17E020001)Fundamental Research Funds of Zhejiang Sci-Tech University(No.2019Q062)。
文摘Two-dimensional (2D) ultrathin MoS2-modified black Ti^3+-TiO2 nanotubes were fabricated using an electrospinning-hydrothermal treatment-reduction method.Bare TiO2 nanotubes were fabricated via electrospinning.Then,2D MoS2 lamellae were grown on the surface of the nanotubes and Ti^3+/Ov ions were introduced by reduction.The photocatalytic performance of the 2D MoS2/Ti^3+-TiO2 nanotubes was^15 times better than that of TiO2.The HER enhancement of the MoS2/Ti^3+-TiO2 nanotubes can be attributed to the Pt-like behavior of 2D MoS2 and the presence of Ti^3+-ions,which facilitated the quick diffusion of the photogenerated electrons to water,reducing the H2 activation barrier.The presence of Ov ions in the nanotubes and their hollow structure increased their solar utilization.
文摘Low‐temperature selective catalytic reduction(SCR)of NO with NH3 was tested over Ho‐doped Mn–Ce/TiO2 catalysts prepared by the impregnation method.The obtained catalysts with different Ho doping ratios were characterized by Brunauer‐Emmett‐Teller(BET),X‐ray diffraction(XRD),temperature‐programmed reduction(H2‐TPR),temperature‐programmed desorption of NH3(NH3‐TPD),X‐ray photoelectron spectroscopy(XPS),and scanning electron microscopy(SEM).The catalytic activities were tested on a fixed bed.Their results indicated that the proper doping amount of Ho could effectively improve the low‐temperature denitrification performance and the SO2 resistance of Mn–Ce/TiO2 catalyst.The catalyst with Ho/Ti of 0.1 presented excellent catalytic activity,with a conversion of more than 90%in the temperature window of 140–220°C.The characterization results showed that the improved SCR activity of the Mn–Ce/TiO2 catalyst caused by Ho doping was due to the increase of the specific surface area,higher concentration of chemisorbed oxygen,higher surface Mn4+/Mn3+ratio,and higher acidity.The SO2 resistance test showed that the deactivating influence of SO2 on the catalyst was irreversible.The XRD and XPS results showed that the main reason for the catalyst deactivation was sulfates that had formed on the catalyst surface and that Ho doping could inhibit the sulfation to some extent.
文摘A series of phosphorus-modified titanium dioxide samples with varying P/Ti atomic ratio were conveniently prepared via a conventional solgel route. The effects of phosphorus content and calcination temperature on the crystalline structure, grain growth, surface area, and the photocatalytic activity of P-modified TiO2 were investigated. The XRD results showed that P species slow down the particle growth of anatase and increase the anatase-to-rutile phase transformation temperature to more than 900°C. Kinetic studies on the P-modified TiO2 to degraded 4-chlorophenol had found that the TP5500 prepared by adopting a P/Ti atomic ratio equal to 0.05 and calcined at 500°C had an apparent rate constant equal to 0.0075 min 1, which is superior to the performance of a commercial photocatalyst Degussa P25 Kapp = 0.0045 min 1 and of unmodified TiO2 （TP0500） Kapp = 0.0022 min 1. From HPLC analyses, various hydroxylated intermediates formed during oxidation had been identified, including hydroquinone （HQ）, benzoquinone （BQ） and （4CC） 4-chlorocatechol as main products. Phytotoxicity was assessed before and after irradiation against seed germination of tomato （Lycopersicon esculentum） whereas acute toxicity was assessed by using Folsomia candida as the test organism. Intermediates products were all less toxic than 4-chlorophenol and a significant removal of the overall toxicity was accomplished
文摘Adding a small amount of nanocrystalline TiO2@C （TiO2 supported on nano- porous carbon） composite dramatically decreases the operating temperatures and improves the reaction kinetics for hydrogen storage in NaAlH4. The nano- crystalline TiO2@C composite synthesized at 900 ℃ （referred as TiO2@C-900） exhibits superior catalytic activity to other catalyst-containing samples. The onset dehydrogenation temperature of the TiO2@C-900-containing sample is lowered to 90 ℃; this is 65 ℃ lower than that of the pristine sample. The dehydrogenated sample is completely hydrogenated at 115 ℃ and 100 bar of hydrogen pressure with a hydrogen capacity of 4.5 wt.%. Structural analyses reveal that the Ti undergoes a reduction process of Ti^4＋→Ti^3＋→Ti^2＋→Ti during the ball milling and heating processes, and further converts to Ti hydrides or forms Ti-Al species after rehydrogenation. The catalytic activities of Ti-based catalytic species decrease in the order Al-Ti-species 〉 TiH0.71 〉 TiH2 〉 TiO2. This understanding guides further improvement in hydrogen storage properties of metal alanates using nanocrvstalline transition metal-based additives.
基金Supported by the Major National Science and Technology Special Project on Treatment and Control of Water Pollution(2009ZX07425-006)the State Key laboratory of Environmental Simulation and Pollution Control (09K04ESPCT)
文摘The adsorption equilibrium of a fluoride solution on 1-2 mm granular activated alumina modified by Fe2(SO4)3 solution was investigated.The experiments were conducted using a wide range of initial fluoride concentrations(0.5 to 180 mg·L-1 at pH～7.0) and an adsorbent dose of 1.0 g·L-1.The application of Langmuir and Freundlich adsorption isotherm models(linear and nonlinear forms) generally showed that a single Langmuir or Freundlich equation cannot fit the entire concentration gap.Experimental data on low equilibrium concentrations(0.1 to 5.0 mg·L-1) was in line with both Langmuir and Freundlich isotherm models,whereas that of high equilibrium concentrations(5.0 to 150 mg·L-1) was more in line with the Freundlich isotherm model.A new LangmuirFreundlich function was used for the entire concentration gap,as well as for low and high concentrations.
基金financially supported by the National Natural Science Foundation of China(No.51472177)the China-EU Science and Technology Cooperation Project(No.SQ2013ZOA100006)
文摘Carbon and few-layer MoS2 nanosheets co- modified TiO2 nanocomposites （defined as MoS2-C@TiO2） were prepared through a facile one-step pyrolysis reaction technique. In this unique nanostructure, the TiO2 nanosh- eets with stable structure serve as the backbones, and carbon coating and few-layer MoS2 tightly adhere onto the surface of the TiO2. It needs to be pointed out that the carbon coating improves the overall electronic conductivity and the few-layer MoS2 facilitates the diffusion of lithium ions and offers more active sites for lithium-ion storage. As a result, when evaluated as lithium-ion battery anodes, the MoS2-C@TiO2 nanocomposites exhibit markedly enhanced lithium storage capability compared with pure TiO2. A high specific capacity of 180 mA.h.g-1 has been achieved during the preliminary cycles, and the specific capacity can maintain 160 mA.h.g-1 at a high current density of 1C （1C=167 mA.g-1） even after 300 discharge/ charge cycles, indicating the great potential of the MoS2- C@TiO2 on energy storage.
基金supported by the National Natural Science Foundation of China (No.61774073)Open Project of State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University (No. 2016-25)Science and Technology Development Program of Jilin province (No. 20170101086JC)
文摘TiO2 nanotube arrays were prepared by means of an electrochemical anodization technique in an organic electrolyte solution doped with polyvinyl pyrrolidone (PVP) and were subsequently modified with phosphomolybdic acid (PMoA) to obtain PMoA/TiO2 nanotube arrays. The microstructure and photochromic properties were investigated via X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet-visible spectroscopy (UV-vis), and X-ray photoelectron spectroscopy (XPS). The results indicated that the Keggin structure of PMoA and the nanotube structure of TiO2 were not destroyed, and there was a strong degree of interaction between PMoA and TiO2 at the biphasic interface with lattice interlacing during the compositing process. The XPS results further indicated that there was a change in the chemical microenvironment during the formation process of the composite, and a new charge transfer bridge was formed through the Mo-O-Ti bond. Under visible light irradiation, the colorless PMoA/TiO2 nanotube array quickly turned blue and exhibited a photochromic response together with reversible photochromism in the presence of H2O2. After visible light irradiation for 60s, the appearance of Mo^5+ species in the XPS spectra indicated a photoreduction process in accordance with a photoinduced electron transfer mechanism.
基金the National Natural Science Foundation of China(51602179,21333006,21573135,11374190)the National Basic Research Program of China(973 Program,2013CB632401)~~
文摘In this study,CuBi2O4 photocathodes were prepared using a simple electrodeposition method for photoelectrochemical(PEC)hydrogen production.The prepared photocathodes were modified with amorphous TiO2 and a Pt co‐catalyst,which resulted in the formation of CuBi2O4/TiO2 p‐n heterojunctions,and enhanced the activities of the as‐prepared photocathodes.The novel Pt/TiO2/CuBi2O4 photocathode exhibited a photocurrent of 0.35 mA/cm2 at 0.60 V vs.Reversible Hydrogen Electrode(RHE),which was nearly twice that of the Pt/CuBi2O4 photocathode.The present study provides a facile method for increasing the efficiency of photocathodes and provides meaningful guidance for the preparation of high‐performance CuBi2O4 photocathodes.
基金Project supported by the Beijing Nova Program(Z181100006218030)Major State Research Development Program of Hebei province(20374202D)。
文摘As the oxygen redox ability shows great effects on the catalytic performances of ceria-zirconia based materials,many strategies have been utilized to improve the oxygen storage capacity.Here in this study,we report a simple and facile approach to prepare a SO_(4)^(2-)-modified La,Y-doped ceria-zirconia material(SO/CZLY-f)with high oxygen storage capacity.Due to the additional redox process between SO_(4)^(2-)and S^(2-),oxygen storage capacity of SO/CZLY-f(745.3μmol O_(2)/g)is about 1.6 times higher than that of La,Ydoped ceria-zirconia material without SO_(4)^(2-)modification.Moreover,the catalytic activities and stability of the corresponding Pd-only three-way catalyst were measured.Compared to that of Pd@CZLY-f,the operation window of CO,full conversion temperature of HC and NO over Pd@SO/CZLY-f are obviously widened and lowered,respectively.After aging treatment at 1100℃for 4 h,the superiority of aged Pdloading composite is still maintained.
