Achieving carbon peak and carbon neutrality goals has driven the development of the hydrogen energy industry,with water electrolysis being a key source of clean hydrogen.However,the slow kinetics of oxygen evolution r...Achieving carbon peak and carbon neutrality goals has driven the development of the hydrogen energy industry,with water electrolysis being a key source of clean hydrogen.However,the slow kinetics of oxygen evolution reaction(OER)at the anode,especially under high current densities,hinders industrial-scale water electrolysis for hydrogen production.The design and fabrication of non-precious metal electrocatalysts with high OER activity at high current densities remain challenging.In this study,we synthesized an Fe(OH)_(x)-NiCoP OER catalyst by electrodepositing amorphous Fe(OH)_(x) onto low-crystallinity phosphides,forming crystalline-amorphous interface nanoneedle arrays.Characterization results revealed that the crystallineamorphous interfaces shortened ion/electron diffusion paths during electrochemical reactions and protected phosphides from corrosion.The incorporation of Fe enhanced the material's conductivity,while the sea urchin-like clustered structure provided a high specific surface area and rough surface.Critically,the superhydrophilic nature of the catalyst facilitated rapid bubble detachment and enhanced electrolyte accessibility,which are pivotal for sustaining high-current-density operation.The Fe(OH)_(x)-NiCoP/NF catalyst exhibited excellent electrocatalytic activity for OER in alkaline solution,demonstrating an overpotential of 357 mV at an industrially relevant current density of 1000 mA cm^(-2) and sustained catalytic activity for 750 h.Surface reconstruction of Fe(OH)_(x)-NiCoP/NF during OER contributed to the improved electrochemical performance.This work underscores the synergistic role of superhydrophilicity and efficient gas release in achieving durable high-current OER performance.By integrating crystalline and amorphous active sites into a multi-component material system,this study offers a novel design strategy for efficient OER electrocatalysts under demanding industrial conditions.展开更多
Designing high-performance electrodes via 3D printing for advanced energy storage is appealing but remains challenging.In normal cases,light-weight carbonaceous materials harnessing excellent electrical conductivity h...Designing high-performance electrodes via 3D printing for advanced energy storage is appealing but remains challenging.In normal cases,light-weight carbonaceous materials harnessing excellent electrical conductivity have served as electrode candidates.However,they struggle with undermined areal and volumetric energy density of supercapacitor devices,thereby greatly impeding the practical applications.Herein,we demonstrate the in situ coupling of NiCoP bimetallic phosphide and Ti3C2 MXene to build up heavy NCPM electrodes affording tunable mass loading throughout 3D printing technology.The resolution of prints reaches 50μm and the thickness of device electrodes is ca.4 mm.Thus-printed electrode possessing robust open framework synergizes favorable capacitance of NiCoP and excellent conductivity of MXene,readily achieving a high areal and volumetric capacitance of 20 F cm^-2 and 137 F cm^-3 even at a high mass loading of^46.3 mg cm^-2.Accordingly,an asymmetric supercapacitor full cell assembled with 3D-printed NCPM as a positive electrode and 3D-printed activated carbon as a negative electrode harvests remarkable areal and volumetric energy density of 0.89 mWh cm^-2 and 2.2 mWh cm^-3,outperforming the most of state-of-the-art carbon-based supercapacitors.The present work is anticipated to offer a viable solution toward the customized construction of multifunctional architectures via 3D printing for high-energy-density energy storage systems.展开更多
Highly efficient,cost-effective,and durable electrocatalysts for hydrogen evolution reaction(HER)in water splitting is crucial for ene rgy conversion and sto rage.Herein,we report NiCoP 1D nanothorn arrays grown on 3D...Highly efficient,cost-effective,and durable electrocatalysts for hydrogen evolution reaction(HER)in water splitting is crucial for ene rgy conversion and sto rage.Herein,we report NiCoP 1D nanothorn arrays grown on 3D porous Ni film current collectors(Ni/NiCoP)as the novel electrocatalytic electrodes.The 3D hierarchically porous nickel films containing large 7±2μm pores and small pores less than 1μm are obtained through using hydrogen bubbles dynamic template method.The NiCoP 1D nanothorns are about 70 nm in diameter and 4-8μm in length.The porous Ni/NiCoP electrocatalytic electrodes demonstrate much higher catalytic activity and remarkable stability for long-term HER.The excellent electrocatalytic performance might be attributed to the inherent nature of highly catalytic active NiCo bimetal phosphides and the unique architecture of 1D nanothorn active materials directly integrated on the 3D hierarchically porous metallic nickel conductive skeletons.The developed electrode has been fabricated to the integrated solar-driven seawater-splitting system.展开更多
The exploration of stable and highly efficient alkaline hydrogen evolution reaction(HER)electrocatalysts is imperative for alkaline water splitting.Herein,Se-doped NiCoP with hierarchical nanoarray structures directly...The exploration of stable and highly efficient alkaline hydrogen evolution reaction(HER)electrocatalysts is imperative for alkaline water splitting.Herein,Se-doped NiCoP with hierarchical nanoarray structures directly grown on carbon cloth(Se-NiCoP/CC)was prepared by hydrothermal reaction and phosphorization/selenization process.The experimental results reveal that Se doping could increase the electrochemical active sites and alter the electronic structure of NiCoP.The optimized Se-NiCoP/CC electrode exhibits outstanding HER activity in alkaline electrolyte,which only needs a low overpotential of 79 mV at the current density of 10 mA/cm^(2).When serving as anode and cathode electrode simultaneously,the Se-NiCoP/CC electrodes achieve current density of 50 mA/cm^(2) at a low voltage of only 1.62 V.This work provides a feasible way to rationally design high active HER electrocatalysts.展开更多
Due to the massive discharge of antibiotics in water,it is an urgent matter to remove antibiotics from waste water.The photocatalysts with high stability and activity have attracted extensive attention from researcher...Due to the massive discharge of antibiotics in water,it is an urgent matter to remove antibiotics from waste water.The photocatalysts with high stability and activity have attracted extensive attention from researchers.By an in-situ polymerization method,polypyrrole(PPy)was modified on the surface of TiO_(2)(named as TiO_(2)/PPy).By one-step reduction method,NiCoP was grafted on the surface of TiO_(2)/PPy(named as TiO_(2)/PPy/NiCoP)to synthesize the photocatalyst of TiO_(2)/PPy/NiCoP for degradation of tetra-cycline(TC)antibiotic.The characterization results revealed that NiCoP was deposited on the surface of TiO_(2)/PPy successfully.The photocatalytic experiment results illustrated that 83.2%of TC could be de-graded at natural pH with 20 mg of TiO_(2)/PPy/NiCoP in 50 mL of TC solution(10 mg/L)under visible light irradiation.The high catalytic activity is attributed to the attachment of NiCoP on the surface of TiO_(2)/PPy which can enlarge the light response range of TiO_(2)effectively.Scavenger studies revealed that the degra-dation of TC was dominated by•O_(2)−and h+.The photodegradation efficiency of TC with TiO_(2)/PPy/NiCoP still reached over 74%after 5 consecutive cycles,indicating the potential applications in practical wastew-ater.展开更多
Hollow nanostructures have attracted increasing research interest in hydrogen evolution reaction owing to their unique structural features.Herein,Ni-Co mixed metal phosphide hollow and porous polyhedrons was successfu...Hollow nanostructures have attracted increasing research interest in hydrogen evolution reaction owing to their unique structural features.Herein,Ni-Co mixed metal phosphide hollow and porous polyhedrons was successfully composited(expressed as NiCoP).Benefiting from the synergistic effects of ZIF-67 by doping Ni elements and the well-defined hollow and porous structure,the as-synthesized NiCoP hollow and porous polyhedrons exhibit better electrochemical properties and mechanical stability for hydrogen evolution reaction over a pH-universal range,with a small Tafel slopes of 72,101,176 mV/dec,and a low overpotential of 82,102,261 mV at a current density of 10 mA/cm^(2) in 0.5 mol/L H_(2)SO_(4),1 mol/L KOH and1 mol/L phosphate buffer solution(PBS).This general strategy can also be applied to fabricate other hollow cobalt-based phosphides and MOFs-derived materials for HER.展开更多
With the energy crisis and global warming,exploration of novel energy sources to replace fossil fuels is a hot topic.H2 is considered as an eco-friendly energy carrier due to its high energy density per unit mass,and ...With the energy crisis and global warming,exploration of novel energy sources to replace fossil fuels is a hot topic.H2 is considered as an eco-friendly energy carrier due to its high energy density per unit mass,and when consumed in engines or fuel cells,it produces only water as the byproduct.Conventional approach to H2 synthesis strongly depends on fossil fuels by steam reforming process,leading to serious CO2 emission.Nowadays,an eco-friendly alternative to produce H2 on a large scale is via electrochemical water splitting[1–7].The overall water splitting reaction consists of two half-reactions:the cathodic hydrogen evolution reaction(HER)and anodic oxygen evolution reaction(OER),both of which require catalysts to improve their efficiency and reduce their overpotentials[8].Although the state-of-the-art catalysts of Pt/C and IrO2/RuO2 exhibit high performance for HER and OER,their widespread uses are hindered by their scarcity and high cost.Moreover,using a bifunctional HER and OER electrocatalyst has advantages of simplifying the system and lowering the cost.As such,it is highly attractive to design and develop earth-abundant bifunctional water-splitting electrocatalysts.Transition-metal phosphides are an important class of compounds formed by the alloying of metals and phosphorus,and their good electrical conductivity is of great benefit to enhanced electrochemical performances[9–12].Recently,Fu’s group from Heilongjiang University have prepared NiCoP nanosheets grown on N-doped carbon coated Ni foam(NiCoP/NF@NC)[13].The linear sweeping voltammetry(LSV)curves show that the NiCoP/NF@NC electrode requires overpotentials of 31.8 mV for the HER and 308.2 mV for the OER to achieve 10 mA/cm^2 in 1.0 M KOH.The HER overpotential is much lower than those for NiP/NF@NC(126.6 mV)and CoP/NF@NC(112.1 mV),demonstrating NiCoP/NF@NC is superior in HER performance to CoP/NF@NC and NiP/NF@NC due to the synergistic effect.Moreover,for the OER catalysis,the overpotential of NiCoP/NF@NC electrode is also lower than those for NiP/NF@NC(349.1 mV)and CoP/NF@NC(383.3 mV).Notably,NiCoP/NF@NC has excellent long-term stability without obvious attenuation of performance after 10000 time cycles.Such 3D catalyst electrode has the following advantages for water splitting:(1)it acts as a bifunctional HER and OER electrocatalyst;(2)Ni foam accelerates the diffusion of ions and improve the electrocatalytic performance;(3)introduction of N-doped carbon nanostructures enhances the electrical conductivity and facilitates the transfer rate of electron.展开更多
基金the National Key Research and Development Program of China(2022YFB1105100)the National Natural Science Foundation of China(U2330105)the funding from Science Foundation of China University of Petroleum,Beijing(24620188JC005).
文摘Achieving carbon peak and carbon neutrality goals has driven the development of the hydrogen energy industry,with water electrolysis being a key source of clean hydrogen.However,the slow kinetics of oxygen evolution reaction(OER)at the anode,especially under high current densities,hinders industrial-scale water electrolysis for hydrogen production.The design and fabrication of non-precious metal electrocatalysts with high OER activity at high current densities remain challenging.In this study,we synthesized an Fe(OH)_(x)-NiCoP OER catalyst by electrodepositing amorphous Fe(OH)_(x) onto low-crystallinity phosphides,forming crystalline-amorphous interface nanoneedle arrays.Characterization results revealed that the crystallineamorphous interfaces shortened ion/electron diffusion paths during electrochemical reactions and protected phosphides from corrosion.The incorporation of Fe enhanced the material's conductivity,while the sea urchin-like clustered structure provided a high specific surface area and rough surface.Critically,the superhydrophilic nature of the catalyst facilitated rapid bubble detachment and enhanced electrolyte accessibility,which are pivotal for sustaining high-current-density operation.The Fe(OH)_(x)-NiCoP/NF catalyst exhibited excellent electrocatalytic activity for OER in alkaline solution,demonstrating an overpotential of 357 mV at an industrially relevant current density of 1000 mA cm^(-2) and sustained catalytic activity for 750 h.Surface reconstruction of Fe(OH)_(x)-NiCoP/NF during OER contributed to the improved electrochemical performance.This work underscores the synergistic role of superhydrophilicity and efficient gas release in achieving durable high-current OER performance.By integrating crystalline and amorphous active sites into a multi-component material system,this study offers a novel design strategy for efficient OER electrocatalysts under demanding industrial conditions.
基金supported by the National Natural Science Foundation of China(51702225)the Natural Science Foundation of Jiangsu Province(BK20170336)。
文摘Designing high-performance electrodes via 3D printing for advanced energy storage is appealing but remains challenging.In normal cases,light-weight carbonaceous materials harnessing excellent electrical conductivity have served as electrode candidates.However,they struggle with undermined areal and volumetric energy density of supercapacitor devices,thereby greatly impeding the practical applications.Herein,we demonstrate the in situ coupling of NiCoP bimetallic phosphide and Ti3C2 MXene to build up heavy NCPM electrodes affording tunable mass loading throughout 3D printing technology.The resolution of prints reaches 50μm and the thickness of device electrodes is ca.4 mm.Thus-printed electrode possessing robust open framework synergizes favorable capacitance of NiCoP and excellent conductivity of MXene,readily achieving a high areal and volumetric capacitance of 20 F cm^-2 and 137 F cm^-3 even at a high mass loading of^46.3 mg cm^-2.Accordingly,an asymmetric supercapacitor full cell assembled with 3D-printed NCPM as a positive electrode and 3D-printed activated carbon as a negative electrode harvests remarkable areal and volumetric energy density of 0.89 mWh cm^-2 and 2.2 mWh cm^-3,outperforming the most of state-of-the-art carbon-based supercapacitors.The present work is anticipated to offer a viable solution toward the customized construction of multifunctional architectures via 3D printing for high-energy-density energy storage systems.
基金supported by the National Natural Science Foundation of China(No.21203236)Guangdong Department of Science and Technology(No.2017A050501052)+1 种基金Guangdong Provincial Key Laboratory(No.2014B030301014)Shenzhen Research Plan(No.JCYJ20160229195455154)。
文摘Highly efficient,cost-effective,and durable electrocatalysts for hydrogen evolution reaction(HER)in water splitting is crucial for ene rgy conversion and sto rage.Herein,we report NiCoP 1D nanothorn arrays grown on 3D porous Ni film current collectors(Ni/NiCoP)as the novel electrocatalytic electrodes.The 3D hierarchically porous nickel films containing large 7±2μm pores and small pores less than 1μm are obtained through using hydrogen bubbles dynamic template method.The NiCoP 1D nanothorns are about 70 nm in diameter and 4-8μm in length.The porous Ni/NiCoP electrocatalytic electrodes demonstrate much higher catalytic activity and remarkable stability for long-term HER.The excellent electrocatalytic performance might be attributed to the inherent nature of highly catalytic active NiCo bimetal phosphides and the unique architecture of 1D nanothorn active materials directly integrated on the 3D hierarchically porous metallic nickel conductive skeletons.The developed electrode has been fabricated to the integrated solar-driven seawater-splitting system.
基金Projects(51772086,51872087,51971089)supported by the National Natural Science Foundation of ChinaProject(2018TP1037-202102)supported by Open Fund of Hunan Provincial Key Laboratory of Advanced Materials for New Energy Storage and Conversion,China+1 种基金Project supported by Student National SIT Innovation Program,ChinaProject(2020CB1007)supported by Hunan Joint International Laboratory of Advanced Materials and Technology for Clean Energy,China。
文摘The exploration of stable and highly efficient alkaline hydrogen evolution reaction(HER)electrocatalysts is imperative for alkaline water splitting.Herein,Se-doped NiCoP with hierarchical nanoarray structures directly grown on carbon cloth(Se-NiCoP/CC)was prepared by hydrothermal reaction and phosphorization/selenization process.The experimental results reveal that Se doping could increase the electrochemical active sites and alter the electronic structure of NiCoP.The optimized Se-NiCoP/CC electrode exhibits outstanding HER activity in alkaline electrolyte,which only needs a low overpotential of 79 mV at the current density of 10 mA/cm^(2).When serving as anode and cathode electrode simultaneously,the Se-NiCoP/CC electrodes achieve current density of 50 mA/cm^(2) at a low voltage of only 1.62 V.This work provides a feasible way to rationally design high active HER electrocatalysts.
基金financial support from the National Natural Science Foundation of China (No. 41603087)Natural Science Foundation of Gansu (No. 20JR5RA282)
文摘Due to the massive discharge of antibiotics in water,it is an urgent matter to remove antibiotics from waste water.The photocatalysts with high stability and activity have attracted extensive attention from researchers.By an in-situ polymerization method,polypyrrole(PPy)was modified on the surface of TiO_(2)(named as TiO_(2)/PPy).By one-step reduction method,NiCoP was grafted on the surface of TiO_(2)/PPy(named as TiO_(2)/PPy/NiCoP)to synthesize the photocatalyst of TiO_(2)/PPy/NiCoP for degradation of tetra-cycline(TC)antibiotic.The characterization results revealed that NiCoP was deposited on the surface of TiO_(2)/PPy successfully.The photocatalytic experiment results illustrated that 83.2%of TC could be de-graded at natural pH with 20 mg of TiO_(2)/PPy/NiCoP in 50 mL of TC solution(10 mg/L)under visible light irradiation.The high catalytic activity is attributed to the attachment of NiCoP on the surface of TiO_(2)/PPy which can enlarge the light response range of TiO_(2)effectively.Scavenger studies revealed that the degra-dation of TC was dominated by•O_(2)−and h+.The photodegradation efficiency of TC with TiO_(2)/PPy/NiCoP still reached over 74%after 5 consecutive cycles,indicating the potential applications in practical wastew-ater.
基金supported by the National Natural Science Foundation of China(Nos.51672109,51802177)the Independent Cultivation Program of Innovation Team of Ji’nan City(No.2019GXRC011)Natural Science Foundation of Shandong Province(No.ZR2018BEM019)。
文摘Hollow nanostructures have attracted increasing research interest in hydrogen evolution reaction owing to their unique structural features.Herein,Ni-Co mixed metal phosphide hollow and porous polyhedrons was successfully composited(expressed as NiCoP).Benefiting from the synergistic effects of ZIF-67 by doping Ni elements and the well-defined hollow and porous structure,the as-synthesized NiCoP hollow and porous polyhedrons exhibit better electrochemical properties and mechanical stability for hydrogen evolution reaction over a pH-universal range,with a small Tafel slopes of 72,101,176 mV/dec,and a low overpotential of 82,102,261 mV at a current density of 10 mA/cm^(2) in 0.5 mol/L H_(2)SO_(4),1 mol/L KOH and1 mol/L phosphate buffer solution(PBS).This general strategy can also be applied to fabricate other hollow cobalt-based phosphides and MOFs-derived materials for HER.
文摘With the energy crisis and global warming,exploration of novel energy sources to replace fossil fuels is a hot topic.H2 is considered as an eco-friendly energy carrier due to its high energy density per unit mass,and when consumed in engines or fuel cells,it produces only water as the byproduct.Conventional approach to H2 synthesis strongly depends on fossil fuels by steam reforming process,leading to serious CO2 emission.Nowadays,an eco-friendly alternative to produce H2 on a large scale is via electrochemical water splitting[1–7].The overall water splitting reaction consists of two half-reactions:the cathodic hydrogen evolution reaction(HER)and anodic oxygen evolution reaction(OER),both of which require catalysts to improve their efficiency and reduce their overpotentials[8].Although the state-of-the-art catalysts of Pt/C and IrO2/RuO2 exhibit high performance for HER and OER,their widespread uses are hindered by their scarcity and high cost.Moreover,using a bifunctional HER and OER electrocatalyst has advantages of simplifying the system and lowering the cost.As such,it is highly attractive to design and develop earth-abundant bifunctional water-splitting electrocatalysts.Transition-metal phosphides are an important class of compounds formed by the alloying of metals and phosphorus,and their good electrical conductivity is of great benefit to enhanced electrochemical performances[9–12].Recently,Fu’s group from Heilongjiang University have prepared NiCoP nanosheets grown on N-doped carbon coated Ni foam(NiCoP/NF@NC)[13].The linear sweeping voltammetry(LSV)curves show that the NiCoP/NF@NC electrode requires overpotentials of 31.8 mV for the HER and 308.2 mV for the OER to achieve 10 mA/cm^2 in 1.0 M KOH.The HER overpotential is much lower than those for NiP/NF@NC(126.6 mV)and CoP/NF@NC(112.1 mV),demonstrating NiCoP/NF@NC is superior in HER performance to CoP/NF@NC and NiP/NF@NC due to the synergistic effect.Moreover,for the OER catalysis,the overpotential of NiCoP/NF@NC electrode is also lower than those for NiP/NF@NC(349.1 mV)and CoP/NF@NC(383.3 mV).Notably,NiCoP/NF@NC has excellent long-term stability without obvious attenuation of performance after 10000 time cycles.Such 3D catalyst electrode has the following advantages for water splitting:(1)it acts as a bifunctional HER and OER electrocatalyst;(2)Ni foam accelerates the diffusion of ions and improve the electrocatalytic performance;(3)introduction of N-doped carbon nanostructures enhances the electrical conductivity and facilitates the transfer rate of electron.
