We demonstrate the fabrication of BiOCl/Bi_2S_3 which is well defined at a large scale. The BiOCl/Bi_2S_3 heterostructures exhibit an enhanced photo-catalytic degradation of methyl orange（MO） compared to BiOCl and B...We demonstrate the fabrication of BiOCl/Bi_2S_3 which is well defined at a large scale. The BiOCl/Bi_2S_3 heterostructures exhibit an enhanced photo-catalytic degradation of methyl orange（MO） compared to BiOCl and Bi_2S_3, attributed to the interface between Bi_2S_3 and BiOCl, which effectively separate the photo-induced electron-hole pairs and suppress their recombination.展开更多
Iron-chromium redox flow batteries (ICRFBs) possess advantages of high safety,long cycle time,and lowcost.Increasing Cr^(3+)/Cr^(2+)reaction activity is suggested as one of the most promising strategies to improve the...Iron-chromium redox flow batteries (ICRFBs) possess advantages of high safety,long cycle time,and lowcost.Increasing Cr^(3+)/Cr^(2+)reaction activity is suggested as one of the most promising strategies to improve the performance and prolong the lifetime of ICRFBs.To improve the slow reaction kinetics of the negative electrode,a type of defected carbon cloth with Bismuth (Bi) catalyst introduction is prepared by defect engineering method and electrochemical deposition,which provided defect sites and active sites to catalyze the redox couple’s reaction of ICRFBs.Furthermore,this modified carbon cloth adsorbs Cr(Ⅲ)hydrate more easily,which has a more stable structure and can significantly improve the performance of ICRFBs.Both experimental analysis and theoretical calculation indicated that the modified electrode has excellent electrocatalytic ability,which can enhance the reaction rate of Cr^(3+)/Cr^(2+),improve capacity retention and stabilize cycling performance.The capacity degradation rate of an ICRFB single cell with the modified electrodes is just 0.23%per cycle at a current density of 140 m A/cm^(2).Additionally,the energy efficiency (EE) remains around 83%,which is 8.45%higher than that of the pristine electrode assembled battery under 60 cycles.This work supplies a simple method to obtain a high-performance electrode material for ICRFBs and makes it a practical solution to promote ICFRBs large-scale commercialization process.展开更多
Electrocatalytic nitrogen reduction reaction(NRR)is an appealing route for the sustainable NH_(3)synthesis,while developing efficientand durable NRR catalysts remains at the heart of achieving high-efficiency N_(2)-to...Electrocatalytic nitrogen reduction reaction(NRR)is an appealing route for the sustainable NH_(3)synthesis,while developing efficientand durable NRR catalysts remains at the heart of achieving high-efficiency N_(2)-to-NH_(3)electrocatalysis.Herein,we rationally combine vacancy and interface engineering to design sulfur-deficient Bi2S3 nanoparticles decorated Ti_(3)C_(2)T_(x)-MXene as an effective NRR catalyst.The developed Bi2S3 nanoparticles decorated Ti_(3)C_(2)T_(x)-MXene(Bi2S3-xTi_(3)C_(2)T_(x))naturally contained abundant S-vacancies and exhibited a dramatically boosted NRR activity with an NH_(3)yield of 68.3μg·h^(-1)mg^(-1)(-0.6 V)and a Faradaic efficiency of 22.5%(-0.4 V),far superior to pure Bi_(2)S_(3)and Ti_(3)C_(2)T_(x)and surpassing almost all ever reported Bi-and MXene-based NRR catalysts.Theoretical investigations unveiled that the exceptional NRR activity of Bi_(2)S_(3-x)/Ti_(3)C_(2)T_(x)stemmed from its dual-active-center system involving both S-vacancies and interfacial-Bi sites,which could synergistically promote N_(2)adsorption and*N_(2)H formation to result in an energetic-favorable NRR process.展开更多
We evaluated bismuth doped cerium oxide catalysts for the continuous synthesis of dimethyl carbonate(DMC)from methanol and carbon dioxide in the absence of a dehydrating agent.Bi_(x)Ce_(1-x)O_(δ)nanocomposites of var...We evaluated bismuth doped cerium oxide catalysts for the continuous synthesis of dimethyl carbonate(DMC)from methanol and carbon dioxide in the absence of a dehydrating agent.Bi_(x)Ce_(1-x)O_(δ)nanocomposites of various compositions(x=0.06-0.24)were coated on a ceramic honeycomb and their structural and catalytic properties were examined.The incorporation of Bi species into the CeO_(2) lattice facilitated controlling of the surface population of oxygen vacancies,which is shown to play a crucial role in the mechanism of this reaction and is an important parameter for the design of ceria-based catalysts.The DMC production rate of the Bi_(x)Ce_(1-x)O_(δ) catalysts was found to be strongly enhanced with increasing Ov concentration.The concentration of oxygen vacancies exhibited a maximum for Bi_(0.12)Ce_(0.88)O_(δ),which afforded the highest DMC production rate.Long-term tests showed stable activity and selectivity of this catalyst over 45 h on-stream at 140°C and a gas-hourly space velocity of 2,880 mL·g_(cat)^(-1)·h^(-1).In-situ modulation excitation diffuse reflection Fourier transform infrared spectroscopy and first-principle calculations indicate that the DMC synthesis occurs through reaction of a bidentate carbonate intermediate with the activated methoxy(-OCH_(3))species.The activation of C0_(2) to form the bidentate carbonate intermediate on the oxygen vacancy sites is identified as highest energy barrier in the reaction pathway and thus is likely the rate-determining step.展开更多
Photoelectrochemistry that use semiconductors to absorb sunlight for water splitting provides an effective method for the development of renewable hydrogen energy in the future.In this paper,a transparent and highly-e...Photoelectrochemistry that use semiconductors to absorb sunlight for water splitting provides an effective method for the development of renewable hydrogen energy in the future.In this paper,a transparent and highly-efficient cobalt-iron oxide(Co_(3)FeO_(x))nano-film was fabricated through hydrothermal method by directional adjustment of atomic ratio to promote the kinetics of BiVO_(4)(BVO)photoanode water oxidation.As a result,the Co_(3)FeO_(x)-modified BVO photoanode(Co_(3)FeO_(x)/BVO)exhibits an impressive photocurrent density of 4.0 mA·cm^(2) at 1.23 V versus reversible hydrogen electrode(RHE),approximately 2.17-fold higher than that of bare BVO,as well as a cathodically shifted onset potential of 320 mV.Transparent catalyst nanolayer structure is clarified by ultraviolet-visible spectroscopy.In addition,the Co_(3)FeO_(x)/BVO photoanode has better stability,and there is no obvious activity degradation after 10 hours of reaction.This strategy provides a broad prospect for the use of water oxidation co-catalyst to achieve effective water splitting.展开更多
The effect of irreversibly adsorbed Bi on commercial Pt/C catalyst toward glucose electro-oxidation re- action （GOR） in different electrolytes （acidic, neutral, alkaline） is studied. Bi is successfully deposited o...The effect of irreversibly adsorbed Bi on commercial Pt/C catalyst toward glucose electro-oxidation re- action （GOR） in different electrolytes （acidic, neutral, alkaline） is studied. Bi is successfully deposited on Pt/C from Bi3＋ containing acidic solution from 0 to 90% coverage degree. The stability of the Bi layer in acid and alkaline corresponded to previous studies and started to dissolve at 0.7 V and 0.8 V versus re- versible hydrogen electrode （RIIE）, respectively. However, in neutral phosphate buffer the layer showed remarkable stability to at least 1.2V versus RHE. Bi modification at low （20%） and high （80%） coverage showed the highest increase in the activity of Pt/C toward GOR by a factor up to 7 due to the increased poisoning resistance of the modified catalyst. The effect of poisoning was especially reduced at high Bi coverage （80%）, which shows that adsorbate blocked by Bi through the third-body effect is effective. Finally, with or without Bi modification GOR on PtIC was most active in alkaline conditions.展开更多
Supported metal(oxide)clusters,with both rich surface sites and high atom utilization efficiency,have shown improved activity and selectivity for many catalytic reactions over nanoparticle and single atom catalysts.Ye...Supported metal(oxide)clusters,with both rich surface sites and high atom utilization efficiency,have shown improved activity and selectivity for many catalytic reactions over nanoparticle and single atom catalysts.Yet,the role of cluster catalysts has been rarely reported in CO_(2)electroreduction reaction(CO_(2)RR),which is a promising route for converting CO_(2)to liquid fuels like formic acid with renewable electricity.Here we develop a bismuth oxide(BiOn)cluster catalyst for highly efficient CO_(2)RR to formate.The BiOn cluster catalyst exhibits excellent activity,selectivity,and stability towards formate production,with a formate Faradaic efficiency of over 90%at a current density up to 500 mA·cm^(−2)in an alkaline membrane electrode assembly electrolyzer,corresponding to a mass activity as high as 3,750 A·gBi−1.The electrolyzer with the BiOn cluster catalyst delivers a remarkable formate production rate of 0.56 mmol·min−1 at a high single-pass CO_(2)conversion of 44%.Density functional theory calculations indicate that Bi4O_(3)cluster is more favorable for stabilizing the HCOO^(*)intermediate than Bi(001)surface and single site BiC_(4)motif,rationalizing the improved formate production over the BiOn cluster catalyst.This work highlights the great importance of cluster catalysts in activity and selectivity control in electrocatalytic CO_(2)conversion.展开更多
BiOX(X=Cl,I,Br)has attracted intensive interest as a photocatalyst for environmental remediation,but its limited pho-tocatalytic activity versus visible light irradiation restricts its practical application.Herein,a F...BiOX(X=Cl,I,Br)has attracted intensive interest as a photocatalyst for environmental remediation,but its limited pho-tocatalytic activity versus visible light irradiation restricts its practical application.Herein,a Fe^(3+)-doped BiOCl_(x)I_(1-x)solid solution(Fe-BiOCl_(x)I_(1-x))was synthesized in situ on an amidoxime-functionalized fibrous support via a one-pot solvothermal approach.Comprehensive characterization and DFT calculations indicate that the robust chelated interaction between ami-doxime groups and Fe^(3+)greatly boosts the crystal growth of nanosized Fe-BiOCl_(x)I_(1–x)on the fibrous surface,simultaneously tunes its electronic structure for improved light harvesting and oxygen vacancy creation,and enables the fibrous support to act as an electron sink for efficient charge separation.These synergistic qualities result in high photocatalytic activity for the degradation of organic contaminants,which outperforms that obtained for unsupported Fe-BiOCl_(x)I_(1-x)and other fibrous samples by several times.Our findings highlight the importance of functionalized support design for the development of efficient BiOX photocatalysts under visible light irradiation.展开更多
基金supported by the National Natural Science Foundation of China (21371023)the National Key Basic Research Program of China (2015CB251100)
文摘We demonstrate the fabrication of BiOCl/Bi_2S_3 which is well defined at a large scale. The BiOCl/Bi_2S_3 heterostructures exhibit an enhanced photo-catalytic degradation of methyl orange（MO） compared to BiOCl and Bi_2S_3, attributed to the interface between Bi_2S_3 and BiOCl, which effectively separate the photo-induced electron-hole pairs and suppress their recombination.
基金supported by the National Natural Science Foundation of China(No.52211530034)General project of Beijing Natural Science Fund(No.3222018)。
文摘Iron-chromium redox flow batteries (ICRFBs) possess advantages of high safety,long cycle time,and lowcost.Increasing Cr^(3+)/Cr^(2+)reaction activity is suggested as one of the most promising strategies to improve the performance and prolong the lifetime of ICRFBs.To improve the slow reaction kinetics of the negative electrode,a type of defected carbon cloth with Bismuth (Bi) catalyst introduction is prepared by defect engineering method and electrochemical deposition,which provided defect sites and active sites to catalyze the redox couple’s reaction of ICRFBs.Furthermore,this modified carbon cloth adsorbs Cr(Ⅲ)hydrate more easily,which has a more stable structure and can significantly improve the performance of ICRFBs.Both experimental analysis and theoretical calculation indicated that the modified electrode has excellent electrocatalytic ability,which can enhance the reaction rate of Cr^(3+)/Cr^(2+),improve capacity retention and stabilize cycling performance.The capacity degradation rate of an ICRFB single cell with the modified electrodes is just 0.23%per cycle at a current density of 140 m A/cm^(2).Additionally,the energy efficiency (EE) remains around 83%,which is 8.45%higher than that of the pristine electrode assembled battery under 60 cycles.This work supplies a simple method to obtain a high-performance electrode material for ICRFBs and makes it a practical solution to promote ICFRBs large-scale commercialization process.
基金This work is supported by the National Natural Science Foundation of China(Nos.51761024 and 52161025)Natural Science Foundation of Gansu Province(No.20JR10RA241)+1 种基金Longyuan Youth Innovative and Entrepreneurial Talents Project(No.[2021]17)“Longyuan Young Talents”Program of Gansu Province.
文摘Electrocatalytic nitrogen reduction reaction(NRR)is an appealing route for the sustainable NH_(3)synthesis,while developing efficientand durable NRR catalysts remains at the heart of achieving high-efficiency N_(2)-to-NH_(3)electrocatalysis.Herein,we rationally combine vacancy and interface engineering to design sulfur-deficient Bi2S3 nanoparticles decorated Ti_(3)C_(2)T_(x)-MXene as an effective NRR catalyst.The developed Bi2S3 nanoparticles decorated Ti_(3)C_(2)T_(x)-MXene(Bi2S3-xTi_(3)C_(2)T_(x))naturally contained abundant S-vacancies and exhibited a dramatically boosted NRR activity with an NH_(3)yield of 68.3μg·h^(-1)mg^(-1)(-0.6 V)and a Faradaic efficiency of 22.5%(-0.4 V),far superior to pure Bi_(2)S_(3)and Ti_(3)C_(2)T_(x)and surpassing almost all ever reported Bi-and MXene-based NRR catalysts.Theoretical investigations unveiled that the exceptional NRR activity of Bi_(2)S_(3-x)/Ti_(3)C_(2)T_(x)stemmed from its dual-active-center system involving both S-vacancies and interfacial-Bi sites,which could synergistically promote N_(2)adsorption and*N_(2)H formation to result in an energetic-favorable NRR process.
基金supported by the National Natural Science Foundation of China(Nos.21773189 and 11974195)Department of Science and Technology of Sichuan Province(19ZDZX0113)Liaoning Revitalization Talents Program(XLYC1807121).
文摘We evaluated bismuth doped cerium oxide catalysts for the continuous synthesis of dimethyl carbonate(DMC)from methanol and carbon dioxide in the absence of a dehydrating agent.Bi_(x)Ce_(1-x)O_(δ)nanocomposites of various compositions(x=0.06-0.24)were coated on a ceramic honeycomb and their structural and catalytic properties were examined.The incorporation of Bi species into the CeO_(2) lattice facilitated controlling of the surface population of oxygen vacancies,which is shown to play a crucial role in the mechanism of this reaction and is an important parameter for the design of ceria-based catalysts.The DMC production rate of the Bi_(x)Ce_(1-x)O_(δ) catalysts was found to be strongly enhanced with increasing Ov concentration.The concentration of oxygen vacancies exhibited a maximum for Bi_(0.12)Ce_(0.88)O_(δ),which afforded the highest DMC production rate.Long-term tests showed stable activity and selectivity of this catalyst over 45 h on-stream at 140°C and a gas-hourly space velocity of 2,880 mL·g_(cat)^(-1)·h^(-1).In-situ modulation excitation diffuse reflection Fourier transform infrared spectroscopy and first-principle calculations indicate that the DMC synthesis occurs through reaction of a bidentate carbonate intermediate with the activated methoxy(-OCH_(3))species.The activation of C0_(2) to form the bidentate carbonate intermediate on the oxygen vacancy sites is identified as highest energy barrier in the reaction pathway and thus is likely the rate-determining step.
基金supported by the National Natural Science Foundation of China(Nos.61674152 and 51902309)the Natural Science Foundation of Fujian Province(No.2018J05097)。
文摘Photoelectrochemistry that use semiconductors to absorb sunlight for water splitting provides an effective method for the development of renewable hydrogen energy in the future.In this paper,a transparent and highly-efficient cobalt-iron oxide(Co_(3)FeO_(x))nano-film was fabricated through hydrothermal method by directional adjustment of atomic ratio to promote the kinetics of BiVO_(4)(BVO)photoanode water oxidation.As a result,the Co_(3)FeO_(x)-modified BVO photoanode(Co_(3)FeO_(x)/BVO)exhibits an impressive photocurrent density of 4.0 mA·cm^(2) at 1.23 V versus reversible hydrogen electrode(RHE),approximately 2.17-fold higher than that of bare BVO,as well as a cathodically shifted onset potential of 320 mV.Transparent catalyst nanolayer structure is clarified by ultraviolet-visible spectroscopy.In addition,the Co_(3)FeO_(x)/BVO photoanode has better stability,and there is no obvious activity degradation after 10 hours of reaction.This strategy provides a broad prospect for the use of water oxidation co-catalyst to achieve effective water splitting.
基金Jane and Aatos Erkko FoundationJenny and Antti Wihuri Foundation for funding
文摘The effect of irreversibly adsorbed Bi on commercial Pt/C catalyst toward glucose electro-oxidation re- action （GOR） in different electrolytes （acidic, neutral, alkaline） is studied. Bi is successfully deposited on Pt/C from Bi3＋ containing acidic solution from 0 to 90% coverage degree. The stability of the Bi layer in acid and alkaline corresponded to previous studies and started to dissolve at 0.7 V and 0.8 V versus re- versible hydrogen electrode （RIIE）, respectively. However, in neutral phosphate buffer the layer showed remarkable stability to at least 1.2V versus RHE. Bi modification at low （20%） and high （80%） coverage showed the highest increase in the activity of Pt/C toward GOR by a factor up to 7 due to the increased poisoning resistance of the modified catalyst. The effect of poisoning was especially reduced at high Bi coverage （80%）, which shows that adsorbate blocked by Bi through the third-body effect is effective. Finally, with or without Bi modification GOR on PtIC was most active in alkaline conditions.
文摘以纳米炭球为载体,采用一步液相还原法合成Bi/C纳米催化材料,并利用XRD、EDX、XPS、SEM和TEM对产物的物相、组成、形貌和元素化学态进行详细表征。结果表明:通过该方法成功合成粒径为3-5 nm的金属Bi纳米粒子,该纳米粒子均匀地负载在纳米炭球表面上,无明显团聚现象。所得到的Bi/C纳米复合粒子对硼氢化钠还原对硝基苯酚(4-NP)具有明显的催化活性;当Bi负载量为26.5 wt.%时,该反应在室温下的反应速率常数可达到0.204min-1;通过阿仑尼乌斯方程得到的表观活化能为39 k J·mol-1。与常见的贵金属催化剂相比,该Bi/C纳米复合粒子具有价格低廉、合成简单以及活性较高的优点。
基金the National Key Research and Development Program of China(No.2021YFA1501503),the National Natural Science Foundation of China(Nos.22002121,22172121,and 22002155)the Open Project Fund of State Key Laboratory of Catalysis(No.N-19-04)+2 种基金the Fundamental Research Funds for the Central Universities(No.2021HQZZ05),the Key Laboratory of Fundamental Chemistry of the State Ethnic Commission(No.2021PTJS25)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA21061010),the Natural Science Foundation of Liaoning Province(No.2021-MS-022)the High-Level Talents Innovation Project of Dalian City(No.2020RQ038).
文摘Supported metal(oxide)clusters,with both rich surface sites and high atom utilization efficiency,have shown improved activity and selectivity for many catalytic reactions over nanoparticle and single atom catalysts.Yet,the role of cluster catalysts has been rarely reported in CO_(2)electroreduction reaction(CO_(2)RR),which is a promising route for converting CO_(2)to liquid fuels like formic acid with renewable electricity.Here we develop a bismuth oxide(BiOn)cluster catalyst for highly efficient CO_(2)RR to formate.The BiOn cluster catalyst exhibits excellent activity,selectivity,and stability towards formate production,with a formate Faradaic efficiency of over 90%at a current density up to 500 mA·cm^(−2)in an alkaline membrane electrode assembly electrolyzer,corresponding to a mass activity as high as 3,750 A·gBi−1.The electrolyzer with the BiOn cluster catalyst delivers a remarkable formate production rate of 0.56 mmol·min−1 at a high single-pass CO_(2)conversion of 44%.Density functional theory calculations indicate that Bi4O_(3)cluster is more favorable for stabilizing the HCOO^(*)intermediate than Bi(001)surface and single site BiC_(4)motif,rationalizing the improved formate production over the BiOn cluster catalyst.This work highlights the great importance of cluster catalysts in activity and selectivity control in electrocatalytic CO_(2)conversion.
基金supported by the National Natural Science Foundation of China(No.5200319221806121)+1 种基金Special Fund Project for Technology Innovation of Tianjin City(20YDTPJC00920)Natural Science Foundation of Tianjin City(15JCQNJC06300).
文摘BiOX(X=Cl,I,Br)has attracted intensive interest as a photocatalyst for environmental remediation,but its limited pho-tocatalytic activity versus visible light irradiation restricts its practical application.Herein,a Fe^(3+)-doped BiOCl_(x)I_(1-x)solid solution(Fe-BiOCl_(x)I_(1-x))was synthesized in situ on an amidoxime-functionalized fibrous support via a one-pot solvothermal approach.Comprehensive characterization and DFT calculations indicate that the robust chelated interaction between ami-doxime groups and Fe^(3+)greatly boosts the crystal growth of nanosized Fe-BiOCl_(x)I_(1–x)on the fibrous surface,simultaneously tunes its electronic structure for improved light harvesting and oxygen vacancy creation,and enables the fibrous support to act as an electron sink for efficient charge separation.These synergistic qualities result in high photocatalytic activity for the degradation of organic contaminants,which outperforms that obtained for unsupported Fe-BiOCl_(x)I_(1-x)and other fibrous samples by several times.Our findings highlight the importance of functionalized support design for the development of efficient BiOX photocatalysts under visible light irradiation.
