Seawater electrolysis for hydrogen production faces inherent challenges, including side reactions, corrosion, and scaling, stemming from the intricate composition of seawater. In response, researchers have turned to c...Seawater electrolysis for hydrogen production faces inherent challenges, including side reactions, corrosion, and scaling, stemming from the intricate composition of seawater. In response, researchers have turned to continuous water splitting using forward osmosis(FO)-driven seawater desalination. However, the necessity of a neutral electrolyte hampers this strategy due to the limited current density and scarcity of precious metals. Herein, this study applies alkali-durable FO membranes to enable self-sustaining seawater splitting, which can selectively withdraw water molecules, from seawater, via concentration gradient. The membranes demonstrates outstanding perm-selectivity of water/ions(~5830 mol mol^(-1)) during month-long alkaline resistance tests, preventing electrolyte leaching(>97% OHàretention) while maintaining ~95%water balance(V_(FO)= V_(electrolysis)) via preserved concentration gradient for consistent forward-osmosis influx of water molecules. With the consistent electrolyte environment protected by the polyamide FO membranes, the Ni Fe-Ar-P catalyst exhibits promising performance: a sustain current density of 360 m A cmà2maintained at the cell voltage of 2.10 V and 2.15 V for 360 h in the offshore seawater, preventing Cl/Br corrosion(98% rejection) and Mg/Ca passivation(99.6% rejection). This research marks a significant advancement towards efficient and durable seawater-based hydrogen production.展开更多
The oxygen evolution reaction （OER） represents the rate-determining step of electrocatalytic water splitting into hydrogen and oxygen. Creating oxygen vacancies and adjusting their density has proven to be an effect...The oxygen evolution reaction （OER） represents the rate-determining step of electrocatalytic water splitting into hydrogen and oxygen. Creating oxygen vacancies and adjusting their density has proven to be an effective strategy to design high-performance OER catalysts. Herein, a hydrogenation method is applied to treat a two-dimensional （2D） iron-cobalt oxide （Fe1Co1Ox-origin）, with the purpose of tuning its oxygen vacancy density. Notably, compared with Fe1Co1Ox-origin, the iron-cobalt oxide hydrogenated at 200℃ and 2.0 MPa optimized conditions exhibits a markedly improved OER activity in 1.0 M KOH （with an overpotential 17 of 225 mV at a current density of 10 mA.cm^-2） and a rapid reaction kinetics （with a Tafel slope of 36.0 mV·dec^-1）. Moreover, the OER mass activity of the hydrogenated oxide is 1.9 times that of Fe1Co1Ox-origin at an overpotential of 350 mV. The experimental results, combined with density functional theory （DFT） calculations, reveal that the optimal control of oxygen vacancies in 2D Fe1Co1Ox via hydrogenation can improve the electronic conductivity and promote OH- adsorption onto nearby low-coordinated Co^3＋ sites, resulting in a significantly enhanced OER activity.展开更多
Single atom catalyst(SAC)refers to a novel catalyst with the active metal atoms individually anchored on the support.Single atom catalysts present the unique appeal due to the high atomic availability and specific act...Single atom catalyst(SAC)refers to a novel catalyst with the active metal atoms individually anchored on the support.Single atom catalysts present the unique appeal due to the high atomic availability and specific activity,as well as the high pathway selectivity.Herein,we summarized the classification,preparation,characterization,and application of single atom catalysts.Finally,the current bottlenecks and the outlooks of the SAC research are discussed.展开更多
Photocatalytic membranes have received increasing attention due to their excellent separation and photodegradation of organic contaminants in wastewater.Herein,we bound Ag-AgBr nanoparticles onto a synthesized polyacr...Photocatalytic membranes have received increasing attention due to their excellent separation and photodegradation of organic contaminants in wastewater.Herein,we bound Ag-AgBr nanoparticles onto a synthesized polyacrylonitrile-ethanolamine(PAN-ETA)membrane with the aid of a chitosan(CS)-TiO_(2) layer via vacuum filtration and in-situ partial reduction.The introduction of the CS-TiO_(2) layer improved surface hydrophilicity and provided attachment sites for the Ag-AgBr nanoparticles.The PAN-ETA/CS-Ti0_(2)/Ag-AgBr photocatalytic membranes showed a relatively high water permeation flux(〜47 L·m^(-2)·h^(-1)·bar^(-1))and dyes rejection(methyl orange:88.22%;congo red:95%;methyl blue:97.41%;rose bengal:99.98%).Additionally,the composite membranes exhibited potential long-term stability for dye/salt separation(dye rejection:-97%;salt rejection:-6.5%).Moreover,the methylene blue and rhodamine B solutions(20 mL,10 mg·L^(-1))were degraded approximately 90.75% and 96.81% in batch mode via the synthesized photocatalytic membranes under visible light irradiation for 30 min.This study provides a feasible method for the combination of polymeric membranes and inorganic catalytic materials.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
基金funding provided by the National Key R&D Program of China (Grant No. 2021YFB3801301)National Natural Science Foundation of China (Grant Nos. 22075076, 22208097 and 22378119)Shanghai Pilot Program for Basic Research (22TQ1400100-4)。
文摘Seawater electrolysis for hydrogen production faces inherent challenges, including side reactions, corrosion, and scaling, stemming from the intricate composition of seawater. In response, researchers have turned to continuous water splitting using forward osmosis(FO)-driven seawater desalination. However, the necessity of a neutral electrolyte hampers this strategy due to the limited current density and scarcity of precious metals. Herein, this study applies alkali-durable FO membranes to enable self-sustaining seawater splitting, which can selectively withdraw water molecules, from seawater, via concentration gradient. The membranes demonstrates outstanding perm-selectivity of water/ions(~5830 mol mol^(-1)) during month-long alkaline resistance tests, preventing electrolyte leaching(>97% OHàretention) while maintaining ~95%water balance(V_(FO)= V_(electrolysis)) via preserved concentration gradient for consistent forward-osmosis influx of water molecules. With the consistent electrolyte environment protected by the polyamide FO membranes, the Ni Fe-Ar-P catalyst exhibits promising performance: a sustain current density of 360 m A cmà2maintained at the cell voltage of 2.10 V and 2.15 V for 360 h in the offshore seawater, preventing Cl/Br corrosion(98% rejection) and Mg/Ca passivation(99.6% rejection). This research marks a significant advancement towards efficient and durable seawater-based hydrogen production.
文摘The oxygen evolution reaction （OER） represents the rate-determining step of electrocatalytic water splitting into hydrogen and oxygen. Creating oxygen vacancies and adjusting their density has proven to be an effective strategy to design high-performance OER catalysts. Herein, a hydrogenation method is applied to treat a two-dimensional （2D） iron-cobalt oxide （Fe1Co1Ox-origin）, with the purpose of tuning its oxygen vacancy density. Notably, compared with Fe1Co1Ox-origin, the iron-cobalt oxide hydrogenated at 200℃ and 2.0 MPa optimized conditions exhibits a markedly improved OER activity in 1.0 M KOH （with an overpotential 17 of 225 mV at a current density of 10 mA.cm^-2） and a rapid reaction kinetics （with a Tafel slope of 36.0 mV·dec^-1）. Moreover, the OER mass activity of the hydrogenated oxide is 1.9 times that of Fe1Co1Ox-origin at an overpotential of 350 mV. The experimental results, combined with density functional theory （DFT） calculations, reveal that the optimal control of oxygen vacancies in 2D Fe1Co1Ox via hydrogenation can improve the electronic conductivity and promote OH- adsorption onto nearby low-coordinated Co^3＋ sites, resulting in a significantly enhanced OER activity.
基金the financial support from the National Natural Science Foundation of China(No.22001228)“Double-First Class”University Construction Project(Nos.C176220100022 and C176220100042)+1 种基金Major Science and Technology Project of Precious Metal Materials Genetic Engineering in Yunnan Province(Nos.2019ZE001-1,202002AB080001-6)the Yunnan Science and Technology Bureau and Yunnan University(No.2019FY003025)。
文摘Single atom catalyst(SAC)refers to a novel catalyst with the active metal atoms individually anchored on the support.Single atom catalysts present the unique appeal due to the high atomic availability and specific activity,as well as the high pathway selectivity.Herein,we summarized the classification,preparation,characterization,and application of single atom catalysts.Finally,the current bottlenecks and the outlooks of the SAC research are discussed.
基金We gratefully acknowledge the financial support from the National Natural Science Foundation of China(Grant No.21908054).
文摘Photocatalytic membranes have received increasing attention due to their excellent separation and photodegradation of organic contaminants in wastewater.Herein,we bound Ag-AgBr nanoparticles onto a synthesized polyacrylonitrile-ethanolamine(PAN-ETA)membrane with the aid of a chitosan(CS)-TiO_(2) layer via vacuum filtration and in-situ partial reduction.The introduction of the CS-TiO_(2) layer improved surface hydrophilicity and provided attachment sites for the Ag-AgBr nanoparticles.The PAN-ETA/CS-Ti0_(2)/Ag-AgBr photocatalytic membranes showed a relatively high water permeation flux(〜47 L·m^(-2)·h^(-1)·bar^(-1))and dyes rejection(methyl orange:88.22%;congo red:95%;methyl blue:97.41%;rose bengal:99.98%).Additionally,the composite membranes exhibited potential long-term stability for dye/salt separation(dye rejection:-97%;salt rejection:-6.5%).Moreover,the methylene blue and rhodamine B solutions(20 mL,10 mg·L^(-1))were degraded approximately 90.75% and 96.81% in batch mode via the synthesized photocatalytic membranes under visible light irradiation for 30 min.This study provides a feasible method for the combination of polymeric membranes and inorganic catalytic materials.
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.
