Rational design of low‐cost and efficient electrocatalysts for ethanol oxidation reaction(EOR)is imperative for electrocatalytic ethanol fuel cells.In this work,we developed a copper‐doped nickel oxyhydroxide(Cu‐do...Rational design of low‐cost and efficient electrocatalysts for ethanol oxidation reaction(EOR)is imperative for electrocatalytic ethanol fuel cells.In this work,we developed a copper‐doped nickel oxyhydroxide(Cu‐doped NiOOH)catalyst via in situ electrochemical reconstruction of a NiCu alloy.The introduction of Cu dopants increases the specific surface area and more defect sites,as well as forms high‐valence Ni sites.The Cu‐doped NiOOH electrocatalyst exhibited an excellent EOR performance with a peak current density of 227 mA·cm^(–2)at 1.72 V versus reversible hydrogen electrode,high Faradic efficiencies for acetate production(>98%),and excellent electrochemical stability.Our work suggests an attractive route of designing non‐noble metal based electrocatalysts for ethanol oxidation.展开更多
As an antibiotic,sulfadiazine has posed a serious threat to humans and ecosystems due to its chronic toxicity.The advanced oxidation processes (AOPs) via heterogeneous catalytic activation of peroxymonosulfate (PMS) h...As an antibiotic,sulfadiazine has posed a serious threat to humans and ecosystems due to its chronic toxicity.The advanced oxidation processes (AOPs) via heterogeneous catalytic activation of peroxymonosulfate (PMS) have significant potential for the degradation of antibiotics.However,there are multiple restrictions including non-specifically binding to target contaminants,which would deplete oxidation capacity,and lacking energy effectiveness due to inefficient utilization of reactive oxygen species (ROS).To overcome these obstacles,we adopted the“bait-hook&destroy”strategy in this study.Herein,we synthesized a novel micrometer-sized Ni OOH hierarchical spheres assembled from nanosheets,which have relatively large specific surface areas and yield specified cavities to“bait-hook”sulfadiazine and PMS onto the surface cavities.This process was further conductive to effective generation of ROS and subsequently“destruction”of sulfadiazine with elevated mass transformation rate.20.4%of sulfadiazine can adsorb to Ni OOH surface in less than 30 min (0.0051 min^(-1)),and then sulfadiazine was completely degraded in 90min intervals in the Ni OOH/PMS system.The degradation rate constant (k=0.0537 min^(-1)) was about5.3,2.5 and 2.2 times higher than that in Ni_(2)O_(3)/PMS,NiO/PMS and Ni(OH)_(2)/PMS system,respectively.This was ascribed to the synergistic catalytic oxidation and adsorption process occurred on the surface of Ni OOH.Appreciably,there were both non-radicals (^(1)O_(2)) and radicals (O_(2)^(·-)and SO_(4)^(·-)) involved in the Ni OOH/PMS system,and^(1)O_(2)was distinguished as the dominated ROS for degradation of sulfadiazine.This study provides a novel strategy via synergistic adsorption and catalytic oxidation,and indicates that the micrometer-sized Ni OOH hierarchical sphere as heterogeneous catalyst is an attractive candidate for potential application of the SR-AOPs technology in water treatment.展开更多
Highly active,durable and inexpensive oxygen evolution reaction(OER)catalysts are crucial for achieving practical and high-efficiency water splitting.Herein,hierarchical interconnected NixCo1−xOOH nanosheet arrays sup...Highly active,durable and inexpensive oxygen evolution reaction(OER)catalysts are crucial for achieving practical and high-efficiency water splitting.Herein,hierarchical interconnected NixCo1−xOOH nanosheet arrays supported on TiO2/Ti substrate have been fabricated through a facile photodeposition method.Compared with pristine NiOOH,the obtained NixCo1−xOOH nanosheet arrays possess larger exposed electrochemical active surface area,faster transfer and collection of electrons and stronger electronic interaction,showing a low overpotential of 350 mV at a current density of 10 mA·cm−2 and a small Tafel slope of 41 mV·dec−1 in basic solutions,with the OER performance superior to pristine NiOOH and most Ni-based catalysts.Furthermore,the NixCo1−xOOH electrode demonstrates excellent stability at the current density of 10 mA·cm−2 for 24 hours,which is attributed to the structural maintenance caused by the good adhesion of the catalyst and the substrate.Our study provides an alternative approach for the rational design of highly active and promising OER electrocatalysts.展开更多
Lignin is the most promising candidate for producing aromatic compounds from biomass.However,the challenge lies in the cleavage of C-C bonds between lignin monomers under mild conditions,as these bonds have high disso...Lignin is the most promising candidate for producing aromatic compounds from biomass.However,the challenge lies in the cleavage of C-C bonds between lignin monomers under mild conditions,as these bonds have high dissociation energy.Electrochemical oxidation,which allows for mild cleavage of C-C bonds,is considered an attractive solution.To achieve low-energy consumption in the valorization of lignin,the use of highly efficient electrocatalysts is essential.In this study,a meticulously designed catalyst consisting of cobalt-doped nickel(oxy)hydroxide on molybdenum disulfide heterojunction was developed.The presence of molybdenum in a high valence state promoted the adsorption of tert-butyl hydroperoxide,leading to the formation of critical radical intermediates.In addition,the incorporation of cobalt doping regulated the electronic structure of nickel,resulting in a lower energy barrier.As a result,the heterojunction catalyst demonstrated a selectivity of 85.36% for cleaving the C_(α)-C_(β)bond in lignin model compound,achieving a substrate conversion of 93.69% under ambient conditions.In addition,the electrocatalyst depolymerized 49.82 wt% of soluble fractions from organosolv lignin(OL),resulting in a yield of up to 13 wt% of aromatic monomers.Significantly,the effectiveness of the prepared electrocatalyst was also demonstrated using industrial Kraft lignin(KL).Therefore,this research offers a practical approach for implementing electrocatalytic oxidation in lignin refining.展开更多
对高效催化剂进行多尺度调控可优化中间体的吸附能量(原子层面),并实现快速传质(三维宏观层面),这对于提升整体水分解性能至关重要.在本工作中,我们首先在镍铁氢氧化物中引入氧空位,然后通过磷化反应将其转化为具有纳米阵列形态的NiFe-V...对高效催化剂进行多尺度调控可优化中间体的吸附能量(原子层面),并实现快速传质(三维宏观层面),这对于提升整体水分解性能至关重要.在本工作中,我们首先在镍铁氢氧化物中引入氧空位,然后通过磷化反应将其转化为具有纳米阵列形态的NiFe-Vo-P催化剂.在析氧反应催化过程中,NiFe-Vo-P表面会原位形成磷酸盐阴离子及具有催化活性的Ni(Fe)OOH,能显著优化反应中间体的吸附强度.结果表明,NiFeVo-P在过电位为289 mV时电流密度可达1.5 A cm^(-2).同时,其超亲水/超疏气纳米阵列形貌可有效促进传质,在25和70℃的条件下,可在~2.0V的电池电压下分别获得580 mA cm^(-2)和1.0 A cm^(-2)的电流密度,是未进行超疏气形貌工程催化剂的电流密度的2倍以上.展开更多
文摘Rational design of low‐cost and efficient electrocatalysts for ethanol oxidation reaction(EOR)is imperative for electrocatalytic ethanol fuel cells.In this work,we developed a copper‐doped nickel oxyhydroxide(Cu‐doped NiOOH)catalyst via in situ electrochemical reconstruction of a NiCu alloy.The introduction of Cu dopants increases the specific surface area and more defect sites,as well as forms high‐valence Ni sites.The Cu‐doped NiOOH electrocatalyst exhibited an excellent EOR performance with a peak current density of 227 mA·cm^(–2)at 1.72 V versus reversible hydrogen electrode,high Faradic efficiencies for acetate production(>98%),and excellent electrochemical stability.Our work suggests an attractive route of designing non‐noble metal based electrocatalysts for ethanol oxidation.
基金funded by the National Key R&D Program of China (No.2018YFC0406503)the National Natural Science Foundation of China (No.52070086)+1 种基金the Natural Science Foundation of Jilin Provincial Science & Technology Department (No.20200403034SF)the Open Project Program of Engineering Research Center of Groundwater Pollution Control and Remediation,Ministry of Education。
文摘As an antibiotic,sulfadiazine has posed a serious threat to humans and ecosystems due to its chronic toxicity.The advanced oxidation processes (AOPs) via heterogeneous catalytic activation of peroxymonosulfate (PMS) have significant potential for the degradation of antibiotics.However,there are multiple restrictions including non-specifically binding to target contaminants,which would deplete oxidation capacity,and lacking energy effectiveness due to inefficient utilization of reactive oxygen species (ROS).To overcome these obstacles,we adopted the“bait-hook&destroy”strategy in this study.Herein,we synthesized a novel micrometer-sized Ni OOH hierarchical spheres assembled from nanosheets,which have relatively large specific surface areas and yield specified cavities to“bait-hook”sulfadiazine and PMS onto the surface cavities.This process was further conductive to effective generation of ROS and subsequently“destruction”of sulfadiazine with elevated mass transformation rate.20.4%of sulfadiazine can adsorb to Ni OOH surface in less than 30 min (0.0051 min^(-1)),and then sulfadiazine was completely degraded in 90min intervals in the Ni OOH/PMS system.The degradation rate constant (k=0.0537 min^(-1)) was about5.3,2.5 and 2.2 times higher than that in Ni_(2)O_(3)/PMS,NiO/PMS and Ni(OH)_(2)/PMS system,respectively.This was ascribed to the synergistic catalytic oxidation and adsorption process occurred on the surface of Ni OOH.Appreciably,there were both non-radicals (^(1)O_(2)) and radicals (O_(2)^(·-)and SO_(4)^(·-)) involved in the Ni OOH/PMS system,and^(1)O_(2)was distinguished as the dominated ROS for degradation of sulfadiazine.This study provides a novel strategy via synergistic adsorption and catalytic oxidation,and indicates that the micrometer-sized Ni OOH hierarchical sphere as heterogeneous catalyst is an attractive candidate for potential application of the SR-AOPs technology in water treatment.
基金supported by the National Natural Science Foundation of China(No.21373182)the Zhejiang Provincial Natural Science Foundation of China(No.LY17B030004).
文摘Highly active,durable and inexpensive oxygen evolution reaction(OER)catalysts are crucial for achieving practical and high-efficiency water splitting.Herein,hierarchical interconnected NixCo1−xOOH nanosheet arrays supported on TiO2/Ti substrate have been fabricated through a facile photodeposition method.Compared with pristine NiOOH,the obtained NixCo1−xOOH nanosheet arrays possess larger exposed electrochemical active surface area,faster transfer and collection of electrons and stronger electronic interaction,showing a low overpotential of 350 mV at a current density of 10 mA·cm−2 and a small Tafel slope of 41 mV·dec−1 in basic solutions,with the OER performance superior to pristine NiOOH and most Ni-based catalysts.Furthermore,the NixCo1−xOOH electrode demonstrates excellent stability at the current density of 10 mA·cm−2 for 24 hours,which is attributed to the structural maintenance caused by the good adhesion of the catalyst and the substrate.Our study provides an alternative approach for the rational design of highly active and promising OER electrocatalysts.
基金supported by the National Science Fund for Distinguished Young Scholars(grant no.31925028)the National Natural Science Foundation of China(grant no.22102019)the Natural Science Foundation of Heilongjiang Province(no.YQ2021C005).
文摘Lignin is the most promising candidate for producing aromatic compounds from biomass.However,the challenge lies in the cleavage of C-C bonds between lignin monomers under mild conditions,as these bonds have high dissociation energy.Electrochemical oxidation,which allows for mild cleavage of C-C bonds,is considered an attractive solution.To achieve low-energy consumption in the valorization of lignin,the use of highly efficient electrocatalysts is essential.In this study,a meticulously designed catalyst consisting of cobalt-doped nickel(oxy)hydroxide on molybdenum disulfide heterojunction was developed.The presence of molybdenum in a high valence state promoted the adsorption of tert-butyl hydroperoxide,leading to the formation of critical radical intermediates.In addition,the incorporation of cobalt doping regulated the electronic structure of nickel,resulting in a lower energy barrier.As a result,the heterojunction catalyst demonstrated a selectivity of 85.36% for cleaving the C_(α)-C_(β)bond in lignin model compound,achieving a substrate conversion of 93.69% under ambient conditions.In addition,the electrocatalyst depolymerized 49.82 wt% of soluble fractions from organosolv lignin(OL),resulting in a yield of up to 13 wt% of aromatic monomers.Significantly,the effectiveness of the prepared electrocatalyst was also demonstrated using industrial Kraft lignin(KL).Therefore,this research offers a practical approach for implementing electrocatalytic oxidation in lignin refining.
基金supported by the National Key R&D Program of China(2021YFB3801301)the National Natural Science Foundation of China(22075076 and 22005098)the Central Government Funds for Guiding Local Science and Technology Development(2021Szvup040)。
文摘对高效催化剂进行多尺度调控可优化中间体的吸附能量(原子层面),并实现快速传质(三维宏观层面),这对于提升整体水分解性能至关重要.在本工作中,我们首先在镍铁氢氧化物中引入氧空位,然后通过磷化反应将其转化为具有纳米阵列形态的NiFe-Vo-P催化剂.在析氧反应催化过程中,NiFe-Vo-P表面会原位形成磷酸盐阴离子及具有催化活性的Ni(Fe)OOH,能显著优化反应中间体的吸附强度.结果表明,NiFeVo-P在过电位为289 mV时电流密度可达1.5 A cm^(-2).同时,其超亲水/超疏气纳米阵列形貌可有效促进传质,在25和70℃的条件下,可在~2.0V的电池电压下分别获得580 mA cm^(-2)和1.0 A cm^(-2)的电流密度,是未进行超疏气形貌工程催化剂的电流密度的2倍以上.
