In recent years, solar desalination and water evaporation/purification with various artificial architectures have drawn significant attention. Herein, we introduce a rational design structure for efficient solar water...In recent years, solar desalination and water evaporation/purification with various artificial architectures have drawn significant attention. Herein, we introduce a rational design structure for efficient solar water evaporation and purification, focusing on the balance between water transportation and thermal insulation.Natural wood after a simple flame treatment on the surface was utilized as the solar absorber, with a high solar absorbance(~90 %), good hydrophilicity, and excellent heat localization abilities. Besides,a thermal insulator(polystyrene foam) was used to further reduce the thermal loss, and the optimized ratio between the water path and thermal insulator was obtained. A set of floating foam-flamed-wood(F-F-wood) devices were fabricated with a high evaporation rate of 3.92 kgm-2 h-1, exhibiting photothermal purification abilities from seawater and wastewater containing organic dyes and heavy metals. This study sheds light on the rational design of scalable and low-cost devices for solar water evaporation and purification.展开更多
Au-Ag alloy nanoparticles with different cavity sizes have great potential for improving photocatalytic performance due to their tunable plasmon effect.In this study,galvanic replacement was combined with co-reduction...Au-Ag alloy nanoparticles with different cavity sizes have great potential for improving photocatalytic performance due to their tunable plasmon effect.In this study,galvanic replacement was combined with co-reduction with the reaction kinetics processes regulated to rapidly synthesize Au-Ag hollow alloy nanoparticles with tunable cavity sizes.The position of the localized surface plasmon resonance(LSPR)peak could be effectively adjusted between 490 nm and 713 nm by decreasing the cavity size of the Au-Ag hollow nanoparticles from 35 nm to 20 nm.The plasmon-enhanced photocatalytic H2 evolution of alloy nanoparticles with different cavity sizes was investigated.Compared with pure P25(TiO2),intact and thin-shelled Au-Ag hollow nanoparticles(HNPs)-supported photocatalyst exhibited an increase in the photocatalytic H2 evolution rate from 0.48μmol h^−1 to 4μmol h^−1 under full-spectrum irradiation.This improved photocatalytic performance was likely due to the plasmon-induced electromagnetic field effect,which caused strong photogenerated charge separation,rather than the generation of hot electrons.展开更多
The performance of lithium-sulfur batteries is deteriorated by the inferior conductivity of sulfur,the shuttle effect of lithium polysulfides(LiPSs),sluggish redox kinetics of polysulfide intermediates and serious vol...The performance of lithium-sulfur batteries is deteriorated by the inferior conductivity of sulfur,the shuttle effect of lithium polysulfides(LiPSs),sluggish redox kinetics of polysulfide intermediates and serious volumetric expansion of sulfur.To overcome these challenges,we report a versatile route to prepare multi-functional nanocomposites with tuable hierarchical structure via ammonium hydroxide(NH_(3)·H_(2) O)induced self-assembly.The versatility of the system has been demonstrated that the organization of the hierarchical structure can be regulated by adding different amounts of NH_(3)·H_(2) O,and WS_(2) and Co_(9)S_(8) with nitrogen-doped carbon coating(denoted as WS_(2)@NC and Co_(9)S_(8)@NC)can be prepared by adding different precursor salts.When the as-prepared materials are applied for Li-S batteries,the WS_(2)@NC composite exhibits a reversible capacity of 1107.4 mAh g^(-1) at 0.1 C after 500 cycles and even 728.9 mAh g^(-1) at2 C for 1000 cycles,which is significantly better than the Co_(9)S_(8) counterpart and other reported WS_(2) sulfur hosts.Experimentally,the advantageous performance of WS_(2) could be attributed to its higher surface area and total pore volume,giving rise to the easier access to electrolyte and better ability to buffer the volume change during the charge/discharge process.Theoretically,the density function theory(DFT)calculation reveals that the as-prepared WS_(2) has a higher binding energy towards LiPSs as well as a lower energy barrier for Li^(+)diffusion on the surface than Co_(9)S_(8).More significantly,the density of states(DOS)analysis further confirms that the superior performance is mainly ascribed to the more prominent shifting and the more charge compensation from d band of W than Co,which increase electronic concentration and give more hybridization of d-p orbitals in the Fermi level of the adsorbed Li2 S4 to accelerate the lithium polysulfide interfacial redox and conversion dynamics in WS_(2).By proposing this mechanism,this work sheds new light on the understanding of catalytic conversion of lithium polysulfides at the atomic level and the strategy to develop advanced cathode materials for high-performance lithium-sulfur batteries.展开更多
TiO_2 nanotubes(TNTs) have drawn tremendous attention owing to their unique architectural and physical properties. Anodizing of titanium foil has proven to be the most efficient method to fabricate well-aligned TNTs,w...TiO_2 nanotubes(TNTs) have drawn tremendous attention owing to their unique architectural and physical properties. Anodizing of titanium foil has proven to be the most efficient method to fabricate well-aligned TNTs,which, however, usually produces amorphous TNTs and needs further thermal annealing. Recently, a water-assisted crystallization strategy has been proposed and investigated by both science and engineering communities. This method is very efficient and energy saving, and it circumvents the drawbacks of thermal sintering approach. In this paper, we review the recent research progress in this kind of lowtemperature crystallization approach. Here, various synthetic methods are summarized, and the mechanisms of the amorphous–crystalline transformation are analyzed. The fundamental properties and applications of the low-temperature products are also discussed. Furthermore, it is proved that the water-assisted crystallization approach is not only applicable to TNTs but also to crystallizing other metal oxides.展开更多
Efforts to improve crop yields with efficient use of fertilizers are needed to guarantee global food security.Enhanced slow-release fertilizer systems(SRFs)encapsulated in biodegradable matrices are being developed to...Efforts to improve crop yields with efficient use of fertilizers are needed to guarantee global food security.Enhanced slow-release fertilizer systems(SRFs)encapsulated in biodegradable matrices are being developed to address this global concern.From a wide range of strategies for SRFs development,we explored a natureinspired solution based on the plant cuticle model and its function as a membrane for water and nutrient transport control.Here,Candelilla wax,extracted from Candelilla wild plants(Euphorbia antisyphilitica),is studied as a renewable slow-release matrix for fertilizers encapsulated by a modified spray chilling process.From this process,microencapsulates containing 40 wt%of phosphorus fertilizer are obtained with distinctive sizes and chemical characteristics,presenting a slow-release behavior.Considering the abovementioned features,novel insights into fertilizer release mechanisms based on plant cuticle models are discussed.展开更多
Because of its high theoretical capacity,MnSe has been identified as a promising candidate as the anode material for sodiumion batteries.However,its fast capacity deterioration due to the huge volume change during the...Because of its high theoretical capacity,MnSe has been identified as a promising candidate as the anode material for sodiumion batteries.However,its fast capacity deterioration due to the huge volume change during the intercalation/deintercalation of sodium ions severely hinders its practical application.Moreover,the sodium storage mechanism of MnSe is still under discussion and requires in-depth investigations.Herein,the unique thorn ball-likeα-MnSe/C nanospheres have been prepared using manganese-containing metal organic framework(Mn-MOF)as a precursor followed by in situ gas-phase selenization at an elevated temperature.When serving as the anode material for sodium-ion battery,the as-preparedα-MnSe/C exhibits enhanced sodium storage capabilities of 416 and 405 mAh g^(-1)at 0.2 and 0.5 A g^(-1)after 100 cycles,respectively.It also shows a superior capacity retention of 275 mA h g^(-1)at 10 A g^(-1)after 2000 cycles,and a rate performance of 279 mA h g^(-1)at 20 A g^(-1).Such sodium storage properties could be attributed to the unique structure offering a highly efficient Na+diffusion kinetics with a diffusion coefficient between 1×10^(-11) and 3×10^(-10) cm^(2) s-1.The density functional theory calculation indicates that the fast Na+diffusion mainly takes place on the(100)plane of MnSe along a V-shaped path because of a relatively low diffusion energy barrier of 0.15 eV.展开更多
The burgeoning growth of lithium-ion batteries(LIBs)has caused great concern for the uninterrupted supply of lithium.Although spent LIBs are a richer source of lithium than the natural resources from ore,salt lake bri...The burgeoning growth of lithium-ion batteries(LIBs)has caused great concern for the uninterrupted supply of lithium.Although spent LIBs are a richer source of lithium than the natural resources from ore,salt lake brine,or seawater,traditional methodology for recycling of lithium in spent LIBs suffers from costly energy consumption and the generation of unfriendly environmental pollutants.展开更多
Magnetite （Fe3O4） has been used for thousands of years as one of the important magnetic materials. The rapid developments of thin film technology in the past few decades attract the attention of material scientists ...Magnetite （Fe3O4） has been used for thousands of years as one of the important magnetic materials. The rapid developments of thin film technology in the past few decades attract the attention of material scientists on the fabrication of magnetite thin films. In this article, we present an overview of recent progress on Fe3O4 thin films. The widely used preparation methods are surveyed, and the effect of sub- strates is discussed. Specifically the modified Fe3O4 thin films exhibit excellent electrical and magnetic properties compared with the pure films. It is noteworthy that modified Fe3O4 thin films can be put into two categories： （1） doped films, where foreign metal ions substitute iron ions at A or B sites： and （2） hybrid films, where magnetite phases are mixed with other materials. Notably, Fe3O4 thin films show great potentials in many applications such as sensors and batteries. It is expected that the investigations of Fe3O4 thin films will give us some breakthroughs in materials science and technology.展开更多
Noble metal-based intermetallics are promising electrocatalysts for sustainable energy conversion and consumption processes.High-temperature pyrolysis(>500°C)methods are used to control their crystalline order...Noble metal-based intermetallics are promising electrocatalysts for sustainable energy conversion and consumption processes.High-temperature pyrolysis(>500°C)methods are used to control their crystalline orderings,critical to their electrocatalytic activity and durability.However,the high temperature would cause severe aggregation,resulting in a low catalytic active surface area.Significant research efforts have been devoted to addressing this issue.This short review summarizes recent research progress on synthesizing noble metal-based intermetallic electrocatalysts by space-confined pyrolysis.We focus on three strategies:isolation in pores,coverture by shells,and immobilization by salts.The advantages and existing problems of different methods are highlighted.Last,important issues to be addressed in future research are also discussed.We hope that this article will stimulate future research to develop high-performance intermetallic catalysts for practical applications.展开更多
Highly conductive and stable electrode materials are usually the focus of high-performance supercapacitors.In this work,a unique design of Ni_(2)P@carbon self-supported composite nanowires directly grown on Ni foam wa...Highly conductive and stable electrode materials are usually the focus of high-performance supercapacitors.In this work,a unique design of Ni_(2)P@carbon self-supported composite nanowires directly grown on Ni foam was applied for a supercapacitor.The Co3O4 nanowire array was first synthesized on the Ni foam substrate,and the resulting Ni_(2)P@carbon nanocomposite was obtained by hydrothermally coating Co_(3)O_(4) with the Ni-ethylene glycol complex followed by gaseous phosphorization.We have discovered that the molecular weight of surfactant polyvinylpyrrolidone(PVP)used in the hydrothermal step,as well as the temperature for phosphorization,played very important roles in determining the electrochemical properties of the samples.Specifically,the sample synthesized using PVP with 10 k molecular weight and phosphorized at 300℃ demonstrated the best supercapacitive performance among the different samples,with the highest capacitance and most stable cyclic retention.When an asymmetric supercapacitor(ASC)was assembled with this Ni_(2)P@carbon sample as the cathode and activated carbon(AC)as the anode,the ASC device showed excellent capacitances of 3.7 and 1.6 F cm^(-2) at 2 and 50 mA cm^(-2),respectively,and it kept a high capacitance of 1.2 F cm^(-2) after 5000 cycles at a current rate of 25 mA cm^(-2).In addition,the ASC could reach a high energy density of about 122.8 Wh kg^(-1) at a power density of 0.15 kW kg^(-1) and 53.3 Wh kg^(-1) at the highest power density of 3.78 kW kg^(-1).Additionally,this device also had the ability to power up 16 red LEDs effortlessly,making it a strong candidate in electrochemical energy storage for practical usage.展开更多
Organic-inorganic perovskite (ABX3) solar cells (PSCs) have attracted wide interest in recent years (1)The power conversion efficiency (PCE) has increased up to 23.7%(NREL Best Research-Cell Efficiency Chart, https://...Organic-inorganic perovskite (ABX3) solar cells (PSCs) have attracted wide interest in recent years (1)The power conversion efficiency (PCE) has increased up to 23.7%(NREL Best Research-Cell Efficiency Chart, https://www.nrel.gov/pv/cell-efficiency.html.展开更多
Hybrid organic-inorganic perovskite solar cells(PSCs)have made rapid progress in efficiency from 3.8%to 25.5%in the past decade[1-3].The hybrid perovskite materials possess a 3D crystal structure with a chemical formu...Hybrid organic-inorganic perovskite solar cells(PSCs)have made rapid progress in efficiency from 3.8%to 25.5%in the past decade[1-3].The hybrid perovskite materials possess a 3D crystal structure with a chemical formula as ABX3,where A is a monovalent cation such as methylammonium(CH3NH3,MA+)and formamidinium(HC(NH_(2)K,FA+),and B is a divalent metal cation such as Pb^(2+),and X is a halide(I,Br,Cl or their mixed)[4].展开更多
This review discusses various parameters that influence and control the organo-metal halide perovskite crystallization process. The effect of the perovskite morphology on the photovoltaic performance is a critical fac...This review discusses various parameters that influence and control the organo-metal halide perovskite crystallization process. The effect of the perovskite morphology on the photovoltaic performance is a critical factor. Moreover, it has a dramatic effect on the stability of the perovskite, which has significant importance for later use of the organo-metal perovskite in assorted applications. In this review, we brought together several research investigations that describe the main parameters that significantly influence perovskite crystallization, for example, the annealing process, the precursor solvent, anti-solvent treatment, and additives to the iteite solutions.展开更多
Owing to its nice performance, low cost, and simple solution-processing, organic-inorganic hybrid perovskite solar cell(PSC) becomes a promising candidate for next-generation high-efficiency solar cells.The power conv...Owing to its nice performance, low cost, and simple solution-processing, organic-inorganic hybrid perovskite solar cell(PSC) becomes a promising candidate for next-generation high-efficiency solar cells.The power conversion efficiency(PCE) has boosted from 3.8% to 25.2% over the past ten years. Despite the rapid progress in PCE, the device stability is a key issue that impedes the commercialization of PSCs. Recently, all-inorganic cesium lead halide perovskites have attracted much attention due to their better stability compared with their organic-inorganic counterpart. In this progress report, we summarize the properties of CsPb(IxBr1-x)3 and their applications in solar cells. The current challenges and corresponding solutions are discussed. Finally, we share our perspectives on CsPb(IxBr1-x)3 solar cells and outline possible directions to further improve the device performance.展开更多
Microplastics are an emerging threat and a big challenge for the environment.The presence of microplastics(MPs)in water is life-threatening to diverse organisms of aquatic ecosystems.Hence,the scientific community is ...Microplastics are an emerging threat and a big challenge for the environment.The presence of microplastics(MPs)in water is life-threatening to diverse organisms of aquatic ecosystems.Hence,the scientific community is exploring deeper to find treatment and removal options of MPs.Various physical,chemical and biological methods are researched for MPs removal,among which few have shown good efficiency in the laboratory.These methods also have a few limitations in environmental conditions.Other than finding a suitable method,the creation of legal restrictions at a governmental level by imposing policies against MPs is still a daunting task in many countries.This review is an effort to place all effectual MP removal methods in one document to compare the mechanisms,efficiency,advantages,and disadvantages and find the best solution.Further,it also discusses the policies and regulations available in different countries to design an effective global policy.Efforts are also made to discuss the research gaps,recent advancements,and insights in the field.展开更多
基金financially supported by the National R&D Program of China (No. 2017YFA0207400)the National Key Research and Development Plan (No. 2016YFA0300801)+1 种基金Program for Innovative and Entrepreneurial Leading Talents of DongguanFundamental Research Funds for the Central Universities (No. ZYGX2018J030)。
文摘In recent years, solar desalination and water evaporation/purification with various artificial architectures have drawn significant attention. Herein, we introduce a rational design structure for efficient solar water evaporation and purification, focusing on the balance between water transportation and thermal insulation.Natural wood after a simple flame treatment on the surface was utilized as the solar absorber, with a high solar absorbance(~90 %), good hydrophilicity, and excellent heat localization abilities. Besides,a thermal insulator(polystyrene foam) was used to further reduce the thermal loss, and the optimized ratio between the water path and thermal insulator was obtained. A set of floating foam-flamed-wood(F-F-wood) devices were fabricated with a high evaporation rate of 3.92 kgm-2 h-1, exhibiting photothermal purification abilities from seawater and wastewater containing organic dyes and heavy metals. This study sheds light on the rational design of scalable and low-cost devices for solar water evaporation and purification.
基金supported by the National Natural Science Foundation of China(No.61704114)the Key areas of Science and Technology Program of Xinjiang Production and Construction Corps,China(No.2018AB004)the National Science Foundation(CBET-1803256).
文摘Au-Ag alloy nanoparticles with different cavity sizes have great potential for improving photocatalytic performance due to their tunable plasmon effect.In this study,galvanic replacement was combined with co-reduction with the reaction kinetics processes regulated to rapidly synthesize Au-Ag hollow alloy nanoparticles with tunable cavity sizes.The position of the localized surface plasmon resonance(LSPR)peak could be effectively adjusted between 490 nm and 713 nm by decreasing the cavity size of the Au-Ag hollow nanoparticles from 35 nm to 20 nm.The plasmon-enhanced photocatalytic H2 evolution of alloy nanoparticles with different cavity sizes was investigated.Compared with pure P25(TiO2),intact and thin-shelled Au-Ag hollow nanoparticles(HNPs)-supported photocatalyst exhibited an increase in the photocatalytic H2 evolution rate from 0.48μmol h^−1 to 4μmol h^−1 under full-spectrum irradiation.This improved photocatalytic performance was likely due to the plasmon-induced electromagnetic field effect,which caused strong photogenerated charge separation,rather than the generation of hot electrons.
基金financially supported by National Key Research and Development Program(2018YFB1502503)Fundamental Research Funds for the Central Universities(ZYGX2019J030)Sichuan Science and Technology Program(2020YJ0299)。
文摘The performance of lithium-sulfur batteries is deteriorated by the inferior conductivity of sulfur,the shuttle effect of lithium polysulfides(LiPSs),sluggish redox kinetics of polysulfide intermediates and serious volumetric expansion of sulfur.To overcome these challenges,we report a versatile route to prepare multi-functional nanocomposites with tuable hierarchical structure via ammonium hydroxide(NH_(3)·H_(2) O)induced self-assembly.The versatility of the system has been demonstrated that the organization of the hierarchical structure can be regulated by adding different amounts of NH_(3)·H_(2) O,and WS_(2) and Co_(9)S_(8) with nitrogen-doped carbon coating(denoted as WS_(2)@NC and Co_(9)S_(8)@NC)can be prepared by adding different precursor salts.When the as-prepared materials are applied for Li-S batteries,the WS_(2)@NC composite exhibits a reversible capacity of 1107.4 mAh g^(-1) at 0.1 C after 500 cycles and even 728.9 mAh g^(-1) at2 C for 1000 cycles,which is significantly better than the Co_(9)S_(8) counterpart and other reported WS_(2) sulfur hosts.Experimentally,the advantageous performance of WS_(2) could be attributed to its higher surface area and total pore volume,giving rise to the easier access to electrolyte and better ability to buffer the volume change during the charge/discharge process.Theoretically,the density function theory(DFT)calculation reveals that the as-prepared WS_(2) has a higher binding energy towards LiPSs as well as a lower energy barrier for Li^(+)diffusion on the surface than Co_(9)S_(8).More significantly,the density of states(DOS)analysis further confirms that the superior performance is mainly ascribed to the more prominent shifting and the more charge compensation from d band of W than Co,which increase electronic concentration and give more hybridization of d-p orbitals in the Fermi level of the adsorbed Li2 S4 to accelerate the lithium polysulfide interfacial redox and conversion dynamics in WS_(2).By proposing this mechanism,this work sheds new light on the understanding of catalytic conversion of lithium polysulfides at the atomic level and the strategy to develop advanced cathode materials for high-performance lithium-sulfur batteries.
基金financially supported by the National R&D Program of China under No.2017YFA0207400National Key Research and Development Plan under No.2016YFA0300801National Natural Science Foundation of China under Nos.51502033,61571079,61131005 and 51572042
文摘TiO_2 nanotubes(TNTs) have drawn tremendous attention owing to their unique architectural and physical properties. Anodizing of titanium foil has proven to be the most efficient method to fabricate well-aligned TNTs,which, however, usually produces amorphous TNTs and needs further thermal annealing. Recently, a water-assisted crystallization strategy has been proposed and investigated by both science and engineering communities. This method is very efficient and energy saving, and it circumvents the drawbacks of thermal sintering approach. In this paper, we review the recent research progress in this kind of lowtemperature crystallization approach. Here, various synthetic methods are summarized, and the mechanisms of the amorphous–crystalline transformation are analyzed. The fundamental properties and applications of the low-temperature products are also discussed. Furthermore, it is proved that the water-assisted crystallization approach is not only applicable to TNTs but also to crystallizing other metal oxides.
文摘Efforts to improve crop yields with efficient use of fertilizers are needed to guarantee global food security.Enhanced slow-release fertilizer systems(SRFs)encapsulated in biodegradable matrices are being developed to address this global concern.From a wide range of strategies for SRFs development,we explored a natureinspired solution based on the plant cuticle model and its function as a membrane for water and nutrient transport control.Here,Candelilla wax,extracted from Candelilla wild plants(Euphorbia antisyphilitica),is studied as a renewable slow-release matrix for fertilizers encapsulated by a modified spray chilling process.From this process,microencapsulates containing 40 wt%of phosphorus fertilizer are obtained with distinctive sizes and chemical characteristics,presenting a slow-release behavior.Considering the abovementioned features,novel insights into fertilizer release mechanisms based on plant cuticle models are discussed.
基金financially supported by the Fundamental Research Funds for the Central Universities(No.ZYGX2019J030)。
文摘Because of its high theoretical capacity,MnSe has been identified as a promising candidate as the anode material for sodiumion batteries.However,its fast capacity deterioration due to the huge volume change during the intercalation/deintercalation of sodium ions severely hinders its practical application.Moreover,the sodium storage mechanism of MnSe is still under discussion and requires in-depth investigations.Herein,the unique thorn ball-likeα-MnSe/C nanospheres have been prepared using manganese-containing metal organic framework(Mn-MOF)as a precursor followed by in situ gas-phase selenization at an elevated temperature.When serving as the anode material for sodium-ion battery,the as-preparedα-MnSe/C exhibits enhanced sodium storage capabilities of 416 and 405 mAh g^(-1)at 0.2 and 0.5 A g^(-1)after 100 cycles,respectively.It also shows a superior capacity retention of 275 mA h g^(-1)at 10 A g^(-1)after 2000 cycles,and a rate performance of 279 mA h g^(-1)at 20 A g^(-1).Such sodium storage properties could be attributed to the unique structure offering a highly efficient Na+diffusion kinetics with a diffusion coefficient between 1×10^(-11) and 3×10^(-10) cm^(2) s-1.The density functional theory calculation indicates that the fast Na+diffusion mainly takes place on the(100)plane of MnSe along a V-shaped path because of a relatively low diffusion energy barrier of 0.15 eV.
基金financially supported by the Key-Area Research and Development Program of Guangdong Province (No.2020B090919003)the National Natural Science Foundation of China (No.51872157)+2 种基金Shenzhen Technical Plan Project (Nos.JCYJ20170412170911187 and JCYJ20170817161753629)Guangdong Technical Plan Project (No.2017B090907005)the Key Project of Core Technology Tackling of Guangdong City of Dongguan (No.2019622119003)
文摘The burgeoning growth of lithium-ion batteries(LIBs)has caused great concern for the uninterrupted supply of lithium.Although spent LIBs are a richer source of lithium than the natural resources from ore,salt lake brine,or seawater,traditional methodology for recycling of lithium in spent LIBs suffers from costly energy consumption and the generation of unfriendly environmental pollutants.
基金financially supported by the National R&D Program of China (Nos.2017YFA0207400 and 2016YFA0300801)the National Natural Science Foundation of China (Nos.51502033,61734002 and 61571079)+1 种基金the International Cooperation Projects (No.2015DFR50870)the Science and Technology Project of Sichuan Province (No.2017JY0002)
文摘Magnetite （Fe3O4） has been used for thousands of years as one of the important magnetic materials. The rapid developments of thin film technology in the past few decades attract the attention of material scientists on the fabrication of magnetite thin films. In this article, we present an overview of recent progress on Fe3O4 thin films. The widely used preparation methods are surveyed, and the effect of sub- strates is discussed. Specifically the modified Fe3O4 thin films exhibit excellent electrical and magnetic properties compared with the pure films. It is noteworthy that modified Fe3O4 thin films can be put into two categories： （1） doped films, where foreign metal ions substitute iron ions at A or B sites： and （2） hybrid films, where magnetite phases are mixed with other materials. Notably, Fe3O4 thin films show great potentials in many applications such as sensors and batteries. It is expected that the investigations of Fe3O4 thin films will give us some breakthroughs in materials science and technology.
基金financially supported by the National Key Research and Development Program(2018YFB1502503)the Sichuan Science and Technology Program(2020YJ0299)financial supports from the Australian Research Council under the future fellowship scheme(FT160100107)。
文摘Noble metal-based intermetallics are promising electrocatalysts for sustainable energy conversion and consumption processes.High-temperature pyrolysis(>500°C)methods are used to control their crystalline orderings,critical to their electrocatalytic activity and durability.However,the high temperature would cause severe aggregation,resulting in a low catalytic active surface area.Significant research efforts have been devoted to addressing this issue.This short review summarizes recent research progress on synthesizing noble metal-based intermetallic electrocatalysts by space-confined pyrolysis.We focus on three strategies:isolation in pores,coverture by shells,and immobilization by salts.The advantages and existing problems of different methods are highlighted.Last,important issues to be addressed in future research are also discussed.We hope that this article will stimulate future research to develop high-performance intermetallic catalysts for practical applications.
基金The authors are grateful to the University of Electronic Science and Technology of China for the fiancial support by providing the start-up fund.
文摘Highly conductive and stable electrode materials are usually the focus of high-performance supercapacitors.In this work,a unique design of Ni_(2)P@carbon self-supported composite nanowires directly grown on Ni foam was applied for a supercapacitor.The Co3O4 nanowire array was first synthesized on the Ni foam substrate,and the resulting Ni_(2)P@carbon nanocomposite was obtained by hydrothermally coating Co_(3)O_(4) with the Ni-ethylene glycol complex followed by gaseous phosphorization.We have discovered that the molecular weight of surfactant polyvinylpyrrolidone(PVP)used in the hydrothermal step,as well as the temperature for phosphorization,played very important roles in determining the electrochemical properties of the samples.Specifically,the sample synthesized using PVP with 10 k molecular weight and phosphorized at 300℃ demonstrated the best supercapacitive performance among the different samples,with the highest capacitance and most stable cyclic retention.When an asymmetric supercapacitor(ASC)was assembled with this Ni_(2)P@carbon sample as the cathode and activated carbon(AC)as the anode,the ASC device showed excellent capacitances of 3.7 and 1.6 F cm^(-2) at 2 and 50 mA cm^(-2),respectively,and it kept a high capacitance of 1.2 F cm^(-2) after 5000 cycles at a current rate of 25 mA cm^(-2).In addition,the ASC could reach a high energy density of about 122.8 Wh kg^(-1) at a power density of 0.15 kW kg^(-1) and 53.3 Wh kg^(-1) at the highest power density of 3.78 kW kg^(-1).Additionally,this device also had the ability to power up 16 red LEDs effortlessly,making it a strong candidate in electrochemical energy storage for practical usage.
基金the National Key Research and Development Program of China (2017YFA0206600)the National Natural Science Foundation of China (51773045, 21572041 and 21772030) for financial support
文摘Organic-inorganic perovskite (ABX3) solar cells (PSCs) have attracted wide interest in recent years (1)The power conversion efficiency (PCE) has increased up to 23.7%(NREL Best Research-Cell Efficiency Chart, https://www.nrel.gov/pv/cell-efficiency.html.
基金supported by the National Key Research and Development Program of China(2017YFA0207400)the National Natural Science Foundation of China(61604032,and 62004027)+4 种基金Sichuan Science and Technology Program(2019JDTD0006)the Fundamental Research Funds for the Central Universities of China(ZYGX2016J206)the China Postdoctoral Science Foundation(2019M663466)the National Key Research and Development Program of China(2017YFA0206600)the National Natural Science Foundation of China(51773045,21772030,51922032,and 21961160720)for financial support。
文摘Hybrid organic-inorganic perovskite solar cells(PSCs)have made rapid progress in efficiency from 3.8%to 25.5%in the past decade[1-3].The hybrid perovskite materials possess a 3D crystal structure with a chemical formula as ABX3,where A is a monovalent cation such as methylammonium(CH3NH3,MA+)and formamidinium(HC(NH_(2)K,FA+),and B is a divalent metal cation such as Pb^(2+),and X is a halide(I,Br,Cl or their mixed)[4].
文摘This review discusses various parameters that influence and control the organo-metal halide perovskite crystallization process. The effect of the perovskite morphology on the photovoltaic performance is a critical factor. Moreover, it has a dramatic effect on the stability of the perovskite, which has significant importance for later use of the organo-metal perovskite in assorted applications. In this review, we brought together several research investigations that describe the main parameters that significantly influence perovskite crystallization, for example, the annealing process, the precursor solvent, anti-solvent treatment, and additives to the iteite solutions.
基金the National Key Research and Development Program of China(2017YFA0206600)the National Natural Science Foundation of China(51773045,21572041 and 21772030)for the financial support
文摘Owing to its nice performance, low cost, and simple solution-processing, organic-inorganic hybrid perovskite solar cell(PSC) becomes a promising candidate for next-generation high-efficiency solar cells.The power conversion efficiency(PCE) has boosted from 3.8% to 25.2% over the past ten years. Despite the rapid progress in PCE, the device stability is a key issue that impedes the commercialization of PSCs. Recently, all-inorganic cesium lead halide perovskites have attracted much attention due to their better stability compared with their organic-inorganic counterpart. In this progress report, we summarize the properties of CsPb(IxBr1-x)3 and their applications in solar cells. The current challenges and corresponding solutions are discussed. Finally, we share our perspectives on CsPb(IxBr1-x)3 solar cells and outline possible directions to further improve the device performance.
文摘Microplastics are an emerging threat and a big challenge for the environment.The presence of microplastics(MPs)in water is life-threatening to diverse organisms of aquatic ecosystems.Hence,the scientific community is exploring deeper to find treatment and removal options of MPs.Various physical,chemical and biological methods are researched for MPs removal,among which few have shown good efficiency in the laboratory.These methods also have a few limitations in environmental conditions.Other than finding a suitable method,the creation of legal restrictions at a governmental level by imposing policies against MPs is still a daunting task in many countries.This review is an effort to place all effectual MP removal methods in one document to compare the mechanisms,efficiency,advantages,and disadvantages and find the best solution.Further,it also discusses the policies and regulations available in different countries to design an effective global policy.Efforts are also made to discuss the research gaps,recent advancements,and insights in the field.
