The extensive use of diesel engines has led to significant emissions of pollutants,especially soot particles,which pose serious risks to both the environment and human health.At present,developing catalysts with low–...The extensive use of diesel engines has led to significant emissions of pollutants,especially soot particles,which pose serious risks to both the environment and human health.At present,developing catalysts with low–temperature activity,low cost,and high stability remains the core challenge in eliminating soot from diesel engine exhaust.This paper first reviews the mechanisms of soot catalytic oxidation.Based on these mechanisms,the current design directions for soot catalysts are summarized and discussed.On the one hand,the effects of modification methods such as doping,loading,and solid solution on the performance of manganese-based catalysts are reviewed from the perspective of intrinsic activity.On the other hand,the research progress on manganese-based catalysts with specific morphological structures for soot oxidation is explored.Following the identification of design strategies,the commonly used preparation methods to achieve these designs are also outlined.Finally,the paper highlights the challenges associated with manganese-based catalysts in soot catalysis and discusses future research and development directions.展开更多
MoS_2 samples with controllable morphologies and structures were synthesized using surfactantassisted hydrothermal processes.The effects of surfactants（PEG,PVP,P123,SDS,AOT,and CTAB）on the morphologies and structure...MoS_2 samples with controllable morphologies and structures were synthesized using surfactantassisted hydrothermal processes.The effects of surfactants（PEG,PVP,P123,SDS,AOT,and CTAB）on the morphologies and structures of MoS_2 samples were investigated.The results revealed that spherical,bulk-like,and flower-like MoS_2 particles assembled by NH4~＋-intercalated MoS_2 nano-sheets were synthesized.The morphologies of the MoS_2 samples and their structures（including the slab length and the number of stacked layers） of MoS_2 nano-sheets in these samples could be controlled by adjusting the surfactants.Mono-dispersed spherical MoS_2 particles could be synthesized with PEG via the creation of MoS_2 nano-sheets with slab lengths shorter than 15 nm and fewer than six stacked layers.Possible formation mechanisms of these MoS_2 samples created via surfactant-assisted hydrothermal processes are proposed.Further,the catalytic activities of MoS_2 samples for anthracene hydrogenation were evaluated in a slurry-bed reactor.The catalyst synthesized with the surfactant PEG exhibited the highest catalytic hydrogenation activity.Compared with the other catalysts,it had a smaller particle size,mono-dispersed spherical morphology,shorter slab length,and fewer stacked layers;these were all beneficial to exposing its active edges.This work provides an efficient approach to synthesize transition metal sulfides with controllable morphologies and structures.展开更多
This work offers a typical understanding of the factors that govern the nanostructures of poly（4-vinyl pyridine）-b-polystyrene-bpoly（4-vinyl pyridine）（P4 VP-b-PS-b-P4 VP） block copolymers（BCs） in dioxane/water...This work offers a typical understanding of the factors that govern the nanostructures of poly（4-vinyl pyridine）-b-polystyrene-bpoly（4-vinyl pyridine）（P4 VP-b-PS-b-P4 VP） block copolymers（BCs） in dioxane/water, in which water is a selective solvent for the P4 VP block. It is achieved through an investigation of the amphiphilic triblock copolymer micelles by variation of three different factors, including water content（above CWC but under the immobile concentration）, temperature（ranging from 20 °C to 80 °C）, and copolymer composition（low and high PS block length）. Transition of bead-like micelles to vesicles is observed with the increase of water content due to the increase of interfacial energy between the copolymer and the solvent. Effect of temperature superposed on that of water content results in various morphologies, such as beads, fibers, rods, capsules, toroids, lamellae, and vesicles. The interfacial tension between the BC and the solvent increases with the increase of water content but decreases with the increase of temperature, indicating that the micellar morphologies are resulted from the competitive interplay between the temperature and the water content and always change in a direction that decreases the interfacial energy. Based on the micellar structures obtained in this work and the effects of temperature superposed on water concentration, a diagram of phase evolution of different micellar morphologies is illustrated here, covering the temperature range from 20 °C to 80 °C and the water content changing from 20 vol% to 35 vol%. For the investigation of BC composition, morphological transition of vesicle-to-fiber, for high PS length, is observed as compared with bead-to-capsule for low PS length, as the temperature changes from 20 °C to 80 °C. Our research complements the protocols to control over the morphologies and the phase diagram describing P4 VP-b-PS-b-P4 VP micellar nanostructures in aqueous solution.展开更多
By hydrolysing titanium isopropoxide in a long hydrocarbon chain surfactant-containing solution, TiO2 fine particles with a diversity of well-defined morphologies was synthesized in this study by a hydrothermal route....By hydrolysing titanium isopropoxide in a long hydrocarbon chain surfactant-containing solution, TiO2 fine particles with a diversity of well-defined morphologies was synthesized in this study by a hydrothermal route. The structural change during the formation process was monitored by scanning electron microscopy, transmission electron microscopy and X-ray diffraction analysis. TiO2 with various morphologies such as particle, sheet, rod, tube and flower-like shape was obtained by carefully controlling the preparation conditions. The experimental results show that the pH value is crucial for shape control of the produced TiO2 because it can change the charge state of the surfactant in the solution and the adsorption potential of the surfactant on the TiO2 surface. The shape evolvement of anatase TiO2 was elucidated by quenching the reaction at different stage and the formation mechanism of different shaped TiO2 was suggested.展开更多
All-inorganic cesium lead bromide(CsPbBr3)perovskite is attracting growing interest as functional materials in photovoltaics and other optoelectronic devices due to its superb stability.However,the fabrication of high...All-inorganic cesium lead bromide(CsPbBr3)perovskite is attracting growing interest as functional materials in photovoltaics and other optoelectronic devices due to its superb stability.However,the fabrication of high-quality CsPbBr3 films still remains a big challenge by solution-process because of the low solubility of the cesium precursor in common solvents.Herein,we report a facile solution-processed approach to prepare high-quality CsPbBr3 perovskite films via a two-step spin-coating method,in which the Cs Br methanol/H2 O mixed solvent solution is spin-coated onto the lead bromide films,followed by an isopropanol-assisted post-treatment to regulate the crystallization process and to control the film morphology.In this fashion,dense and uniform CsPbBr3 films are obtained consisting of large crystalline domains with sizes up to microns and low defect density.The effectiveness of the resulting CsPbBr3 films is further examined in perovskite solar cells(PSCs)with a simplified planar architecture of fluorine–doped tin oxide/compact Ti O2/CsPbBr3/carbon,which deliver a maximum power conversion efficiency of 8.11%together with excellent thermal and humidity stability.The present work offers a simple and effective strategy in fabrication of high-quality CsPbBr3 films for efficient and stable PSCs as well as other optoelectronic devices.展开更多
Transition metal dichalcogenides(TMDs)have emerged as a promising electrocatalyst for hydrogen evo-lution reaction(HER)due to its excellent conductivity and abundant electrocatalytic active sites of its edges.TMDs nan...Transition metal dichalcogenides(TMDs)have emerged as a promising electrocatalyst for hydrogen evo-lution reaction(HER)due to its excellent conductivity and abundant electrocatalytic active sites of its edges.TMDs nanowall can expose abundant of edges so that they tend to show better catalytic performance for hydrogen evolution reaction.Herein,PtSe_(2) nanowall films with morphology controlled at centimeters level are synthesized by selenizing Pt film.The dynamic and thermodynamics of selenation reaction are investigated.The nanowall structure can be obtained by controlling the growth temperature,and the thickness of nanowall can be tuned by the original thickness of Pt film.The Pt atoms can be rearranged into ordered distribution at 550℃ and can be induced to well-ordered PtSe_(2) nanowalls finally.The well-ordered PtSe_(2) nanowall films show excellent HER performance,with an overpotential of 0.3 V at-10 mA·cm^(-2) and a Tafel slope of~52 mV·dec^(-1).This work demonstrates the great potential of activated 2D PtSe_(2) as an ultrathin film catalyst for the HER,which is valuable to provide instruction and afford experience for further application at industrial level.展开更多
Al2O3 powders with different morphologies,namely fibrous,sheet-like,and spherical,were prepared by the hydrothermal-thermolysis method.Subsequently,polycrystalline,transparent cerium doped lutetium aluminum garnet（Lu...Al2O3 powders with different morphologies,namely fibrous,sheet-like,and spherical,were prepared by the hydrothermal-thermolysis method.Subsequently,polycrystalline,transparent cerium doped lutetium aluminum garnet（Lu3Al5O（12）：Ce^3＋）green phosphors were synthesized by high temperature solidstate method using commercial lutetium（III）oxide,cerium（III）oxide,and as-prepared Al2O3 powders with different morphologies.The phases,morphologies,and photoluminescent properties of the prepared phosphors were investigated by X-ray diffraction（XRD）,scanning electron microscopy（SEM）,and photoluminescence spectroscopy（PL）.Moreover,the influences of the morphologies ofα-Al2O3 on the types of crystal structure,morphologies,and photoluminescent properties of LuAG：Ce^3＋green phosphors were investigated.The results indicated that the morphologies and particle sizes of theα-Al2O3 powders could be controlled by the additives and parameters.Notably,the sphericalα-Al2O3 powders with good dispersibility were found to be the excellent base materials of LuAG：Ce^3＋green phosphors for white light emitting diodes.展开更多
Using SrC12-6H2O and Na2CO3 as the main raw materials and adding different complexons as modifiers with simple co-precipitation method, SrCO3 crystals with distinct morphologies like spherical, bundle-like, overlappin...Using SrC12-6H2O and Na2CO3 as the main raw materials and adding different complexons as modifiers with simple co-precipitation method, SrCO3 crystals with distinct morphologies like spherical, bundle-like, overlapping plate-like, hexagonal star-like, dumbbell-like, etc. can be synthesized in the ethanol-water mixtures. The samples were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and Fourier transform infrared spectrograph （FT-IR）. The interrelated effect mechanism is presented in the end. Results show that the modifier carboxyl groups play a significant role in controlling the SrCO3 crystal morphologies, which can alter the crystal growth unit （Sr^2＋） supply mode and induce the crystal formation with the morphologies matching their spatial configurations.展开更多
Four shapes of Cu2O particles as sphere,cube,truncated octahedron and octahedron were prepared via glucose reduction of Cu(Ⅱ)under alkaline condition.The products were characterized by XRD and SEM.The effects of the ...Four shapes of Cu2O particles as sphere,cube,truncated octahedron and octahedron were prepared via glucose reduction of Cu(Ⅱ)under alkaline condition.The products were characterized by XRD and SEM.The effects of the precursor(CuO,Cu(OH)2), reaction temperature and glucose concentration on morphology of Cu2O particles were investigated,and the mechanism of morphology control was discussed on the basic theory of crystal nucleation and growth.It is found that the Cu+supersaturation is remarkably influenced by the precursor kind,reaction temperature and glucose concentration,and the morphology of Cu2O particles can be controlled by the Cu+supersaturation.展开更多
The plane form of a gully can provide a basis for evaluating the gully volume and erosion rate, acting process, and evolutionary stage. For describing the planar characteristics of a permanent gully and understanding ...The plane form of a gully can provide a basis for evaluating the gully volume and erosion rate, acting process, and evolutionary stage. For describing the planar characteristics of a permanent gully and understanding their controlling factors, this study, utilizing a total station and GPS RTK, measured the shoulder lines and channel curves of 112 gullies in six sites of the Yuanmou Dry-hot Valley and then mapped them by Arc GIS software and calculated nine parameters. The results showed that the channel lengths range from 10.88 to 249.11 m; the widths range from 6.20 to 40.99 m; the perimeters range from 54.11 to 541.67 m; the gully areas range from 153.02 to 6,930.30 m2; the left-side areas range from 92.93 to 4,027.20 m2; and the right-side areas range from 63.65 to 3,539.77 m2. The slightly sinuous and straight gullies account for 73.21% of the total gullies; the quantity of the right skewed gullies is 8.93% greater than that of the left skewed ones based on the symmetry ratio; the shape ratios range from 1.12 to 1.40 and the morphology ratios from 0.038 to 1.294; the fractal dimension is 1.192. Gullies in different sites have diverse planar characteristics. Except for the symmetry index, which was close to a negatively skewed distribution, all of the other parameters had the characteristic of positively skewed distribution. The gully area is related to the length and width, but the gully length has a weak correlation with the width. The evolutionary stage, topographic conditions, strata, soil properties, and piping erosion played very important roles in the gully planar morphology. This study could provide useful information for controlling gully erosion and safeguarding human habitation and engineering buildings.展开更多
We here report a new CO_2 capture and storage method that converts CO_2 into a novel alkyl carbonate salt, denoted as CO_2 SM, by a system consisting of equimolar 1,4-butanediol(BDO) and 1,2-ethylenediamine(EDA). This...We here report a new CO_2 capture and storage method that converts CO_2 into a novel alkyl carbonate salt, denoted as CO_2 SM, by a system consisting of equimolar 1,4-butanediol(BDO) and 1,2-ethylenediamine(EDA). This novel CO_2 SM was then used to prepare BaCO_3 crystals through a simple and fast hydrothermal synthesis under mild conditions. The CO_2 SM was both the source of CO_2 and the modifier to regulate the nucleation and growth of BaCO_3 crystals. The morphology of the BaCO_3 crystals could be tuned from rod to shuttle by adjusting the key influencing factors, including CO_2 SM concentration, mineralization temperature, and mineralization time. A possible mechanism for the synthesis of BaCO_3 crystals from the CO_2 SM was also presented. After the BaCO_3 crystals were isolated, the filtrate of the hydrothermal reaction could be recycled to again absorb CO_2 and prepare BaCO_3 crystals of the same polymorph. This novel approach appears promising for preparing well-formed metal carbonates.展开更多
Hydrogen is a promising renewable energy source for fossil-free transportation and electrical energy generation.However,leaking hydrogen in high-temperature production processes can cause an explosion,which endangers ...Hydrogen is a promising renewable energy source for fossil-free transportation and electrical energy generation.However,leaking hydrogen in high-temperature production processes can cause an explosion,which endangers production workers and surrounding areas.To detect leaks early,we used a sensor material based on a wide bandgap aluminum nitride(AlN)that can withstand a high-temperature environment.Three unique AlN morphologies(rod-like,nest-like,and hexagonal plate-like)were synthesized by a direct nitridation method at 1400℃usingγ-AlOOH as a precursor.The gas-sensing performance shows that a hexagonal plate-like morphology exhibited p-type sensing behavior and showed good repeatability as well as the highest response(S=58.7)toward a 750 ppm leak of H2 gas at high temperature(500°C)compared with the rod-like and nest-like morphologies.Furthermore,the hexagonal plate-like morphology showed fast response and recovery times of 40 and 82 s,respectively.The surface facet of the hexagonal morphology of AlN might be energetically favorable for gas adsorption–desorption for enhanced hydrogen detection.展开更多
Organic amines are important solvent and raw material in laboratory and industry,as well as releasing from cigarette smoke.It is significant to detect low-concentration amines for environment and public health.Here we...Organic amines are important solvent and raw material in laboratory and industry,as well as releasing from cigarette smoke.It is significant to detect low-concentration amines for environment and public health.Here we reported that as-synthesized zinc oxide is an effective electrode material of electrochemical sensor for the detection of amines.The characterization results reveal that the ZnO morphologies experienced a change from hexagonal bowl-like microparticles,cones,prisms to nanoparticles by adjusting the reaction time,temperature,solvents and additives.Interestingly,ZnO material possessing hexagonal shapes and different sizes exhibits distinct electrochemical response in various amines solution,suggesting that there is a better dependent relationship between different morphological ZnO and amines detection.Particularly,regular hexagonal ZnO nanotablets exhibit a detectable electrochemical response and selectivity to ammonia,implying it can be serve as electrode material for highly effective detection of organic amines.展开更多
Cobalt nanowires with different shapes and sizes were synthesized by reduction of carboxylate salts of Co^(Ⅱ) in 1,2-butanediol using a solvothermal chemical process.The well-crystallized Co nanowires with hexagonal ...Cobalt nanowires with different shapes and sizes were synthesized by reduction of carboxylate salts of Co^(Ⅱ) in 1,2-butanediol using a solvothermal chemical process.The well-crystallized Co nanowires with hexagonal closepacked(hep) phase are observed and the(002) crystalline direction is along the long axis of nano wires.The morphology control is strongly dependent on the reaction parameters.By varying the amount of capping agent in proper ranges,the effect of reaction parameters on controlling the size and shape of Co nanowires is demonstrated.With the amount of capping agent increasing,the aspect ratio of Co nanowires increases remarkably.However,the magnetic measurement of cobalt nanowires shows that the coercivity of the Co nanocrystals does not increase with the increase in aspect ratio monotonously,which suggests that the tip shape and micros tructure also play an important role in the magnetization reversal process of the Co nanocrystals,and the aspect ratio plays a much less role as the ratio value exceeds 11.To further understand the effect of size on the magnetic properties in the Co nanowires,micromagnetic simulations were performed,which confirms that the magnetic properties are barely affected by the aspect ratio larger than 10.The highest coercivity of624 kA·m^(-1) is obtained for ellipsoid nano wires with a mean length of 200 nm,which also displays a strong magnetic anisotropy.As a result,the highest energy product of the wires reaches 248 kJ·m^(-3).展开更多
Preferential orientation control of metal—organic framework(MOF)films is advantageous for maximizing pore uniformity and minimizing grain-boundary defects.Nonetheless,the preparation of MOF films with both in-plane a...Preferential orientation control of metal—organic framework(MOF)films is advantageous for maximizing pore uniformity and minimizing grain-boundary defects.Nonetheless,the preparation of MOF films with both in-plane and out-of-plane orientations remains a grand challenge.In this study,we reported the preparation of three-dimensionally oriented MIL-96 layers through combining morphology control of MIL-96 seeds with addition of polyvinylpyrrolidone surfactants and arachidonic acids.The three-dimensionally oriented MIL-96 film was readily obtained through in-plane epitaxial growth.It is anticipated that the aforementioned protocol can be effective for obtaining diverse MOF films with a three-dimensionally oriented organization.展开更多
Organic photovoltaics(OPVs)need to overcome limitations such as insufficient thermal stability to be commercialized.The reported approaches to improve stability either rely on the development of new materials or on ta...Organic photovoltaics(OPVs)need to overcome limitations such as insufficient thermal stability to be commercialized.The reported approaches to improve stability either rely on the development of new materials or on tailoring the donor/acceptor morphology,however,exhibiting limited applicability.Therefore,it is timely to develop an easy method to enhance thermal stability without having to develop new donor/acceptor materials or donor–acceptor compatibilizers,or by introducing another third component.Herein,a unique approach is presented,based on constructing a polymer fiber rigid network with a high glass transition temperature(T_(g))to impede the movement of acceptor and donor molecules,to immobilize the active layer morphology,and thereby to improve thermal stability.A high-T_(g) one-dimensional aramid nanofiber(ANF)is utilized for network construction.Inverted OPVs with ANF network yield superior thermal stability compared to the ANF-free counterpart.The ANF network-incorporated active layer demonstrates significantly more stable morphology than the ANF-free counterpart,thereby leaving fundamental processes such as charge separation,transport,and collection,determining the device efficiency,largely unaltered.This strategy is also successfully applied to other photovoltaic systems.The strategy of incorporating a polymer fiber rigid network with high T_(g) offers a distinct perspective addressing the challenge of thermal instability with simplicity and universality.展开更多
As an emerging photovoltaic technology,organic solar cells(OSCs)have attracted extensive attention in recent years due to the advantages of light weight,flexibility,semi-transparency,and potential for roll-to-roll dev...As an emerging photovoltaic technology,organic solar cells(OSCs)have attracted extensive attention in recent years due to the advantages of light weight,flexibility,semi-transparency,and potential for roll-to-roll device fabrication.Currently,state-of-the-art OSCs have achieved over 20%power conversion efficiency(PCE),indicating their bright application prospects.Thus,stability becomes a critical issue for the commercialization of OSCs.In practical environments,light and heat are the main factors affecting the stability of OSCs.In this review,we first summarize the key degradation routes induced by thermal and light stresses.Then,recent strategies to enhance thermo-and photostability of OSCs are reviewed,focusing on material design and morphology control.Finally,some suggestions are provided for the development of next-generation OSCs with high efficiency and excellent stability.展开更多
Ag3PO4 is found to be a highly efficient photocatalyst and receives great attention. The high activity of the photocatalyst is credited to the intrinsic electronic structure. The morphology control and nano-composite ...Ag3PO4 is found to be a highly efficient photocatalyst and receives great attention. The high activity of the photocatalyst is credited to the intrinsic electronic structure. The morphology control and nano-composite fabrication are used to improve the performance and practicability. This paper reviews the structure, properties and some theoretical aspects of Ag3PO4 single crystal. Also, the major strategies, namely the morphology control and hetero-nanostructure construction, as ways to improve the performance of Ag3PO4-based photocatalysts, are summarized with the aid of some typical instances.展开更多
The efficient utilization of photocatalytic technology is essential for clean energy.Bismuth-based multimetal oxides(Bi_(2)WO_(6),Bi_(2)MoO_(6),BiVO_(4)and Bi_(4)Ti_(3)O_(12))have aroused widespread attention as a vis...The efficient utilization of photocatalytic technology is essential for clean energy.Bismuth-based multimetal oxides(Bi_(2)WO_(6),Bi_(2)MoO_(6),BiVO_(4)and Bi_(4)Ti_(3)O_(12))have aroused widespread attention as a visible light responsive photocatalyst for hydrogen evolution due to their low cost,nontoxicity,modifiable morphology,and outstanding optical and chemical properties.Nevertheless,the photocatalytic activities of pure materials are unsatisfactory because of their relative small specific surface area,poor quantum yield,and the rapid recombination of photogenerated carriers.Therefore,some modification strategies,including morphological control,semiconductor combination,doping,and defect engineering,have been systematically studied to enhance photocatalytic H_(2)evolution activity in the past few years.Herein,we summarize the recent research progress on bismuth-based photocatalysts,pointing out the prospects,opportunities and challenges of bismuth-based photocatalysts.Eventually,we aims to put forward valuable suggestions for designing of bismuth-based photocatalysts applied in hydrogen production on the premise of consolidating the existing theoretical basis of photocatalysis.展开更多
BaCO3 whiskers exhibiting different morphologies were fabricated by a simple precipitation reaction of barium ch/oride with sodium carbonate in the absence and presence of poly-（styrene-alt-maleic acid） （PSMA） as ...BaCO3 whiskers exhibiting different morphologies were fabricated by a simple precipitation reaction of barium ch/oride with sodium carbonate in the absence and presence of poly-（styrene-alt-maleic acid） （PSMA） as a crystal growth modifier at room temperature. The as-prepared products were characterized by scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, and X-ray diffraction （XRD）. The influences of experimental parameters on the size and morphology of BaCO3 whiskers were investigated and discussed. It was found that the as-prepared BaCO3 whiskers are single crystals with diameter ranging from 100 to 300 run, and grow along the crystallographic a-axis or [100] direction. BaCO3 whiskers with different morphologies, such as branching and dendritic structure, can be obtained depending on the experimental conditions. With increasing PSMA concentration, the diameter of BaCO3 whiskers decreases.展开更多
基金sponsored by the National Natural Science Foundation of China(Grant 22406050)the Top-Notch Personnel Fund of Henan Agricultural University(Grant 30501029)+2 种基金the Natural Science Foundation of Henan Province(Grant 232300420293)the Science and Technology Project of China Tobacco Shaanxi Industrial Co.,Ltd.(Grant BA000-ZB24010)the Postgraduate Education Reform and Quality Improvement Project of Henan Province(Grant YJS2024JD17).
文摘The extensive use of diesel engines has led to significant emissions of pollutants,especially soot particles,which pose serious risks to both the environment and human health.At present,developing catalysts with low–temperature activity,low cost,and high stability remains the core challenge in eliminating soot from diesel engine exhaust.This paper first reviews the mechanisms of soot catalytic oxidation.Based on these mechanisms,the current design directions for soot catalysts are summarized and discussed.On the one hand,the effects of modification methods such as doping,loading,and solid solution on the performance of manganese-based catalysts are reviewed from the perspective of intrinsic activity.On the other hand,the research progress on manganese-based catalysts with specific morphological structures for soot oxidation is explored.Following the identification of design strategies,the commonly used preparation methods to achieve these designs are also outlined.Finally,the paper highlights the challenges associated with manganese-based catalysts in soot catalysis and discusses future research and development directions.
基金supported by the National Natural Science Foundation of China(21303186)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA07020300)~~
文摘MoS_2 samples with controllable morphologies and structures were synthesized using surfactantassisted hydrothermal processes.The effects of surfactants（PEG,PVP,P123,SDS,AOT,and CTAB）on the morphologies and structures of MoS_2 samples were investigated.The results revealed that spherical,bulk-like,and flower-like MoS_2 particles assembled by NH4~＋-intercalated MoS_2 nano-sheets were synthesized.The morphologies of the MoS_2 samples and their structures（including the slab length and the number of stacked layers） of MoS_2 nano-sheets in these samples could be controlled by adjusting the surfactants.Mono-dispersed spherical MoS_2 particles could be synthesized with PEG via the creation of MoS_2 nano-sheets with slab lengths shorter than 15 nm and fewer than six stacked layers.Possible formation mechanisms of these MoS_2 samples created via surfactant-assisted hydrothermal processes are proposed.Further,the catalytic activities of MoS_2 samples for anthracene hydrogenation were evaluated in a slurry-bed reactor.The catalyst synthesized with the surfactant PEG exhibited the highest catalytic hydrogenation activity.Compared with the other catalysts,it had a smaller particle size,mono-dispersed spherical morphology,shorter slab length,and fewer stacked layers;these were all beneficial to exposing its active edges.This work provides an efficient approach to synthesize transition metal sulfides with controllable morphologies and structures.
基金financially supported by Key Lab of Renewable Energy Foundation of Chinese Academy of Sciences(No.Y609JK1001)the National Natural Science Foundation of China for Major Program(Nos.51433009 and 51576201)+2 种基金Natural Science Foundation of Guangdong(No.2015A030313716)Natural Science Foundation of Guangdong for Research Team(No.2015A030312007)Guangdong Science and Technology Project(Nos.2013B050800007 and 2013J4500027)
文摘This work offers a typical understanding of the factors that govern the nanostructures of poly（4-vinyl pyridine）-b-polystyrene-bpoly（4-vinyl pyridine）（P4 VP-b-PS-b-P4 VP） block copolymers（BCs） in dioxane/water, in which water is a selective solvent for the P4 VP block. It is achieved through an investigation of the amphiphilic triblock copolymer micelles by variation of three different factors, including water content（above CWC but under the immobile concentration）, temperature（ranging from 20 °C to 80 °C）, and copolymer composition（low and high PS block length）. Transition of bead-like micelles to vesicles is observed with the increase of water content due to the increase of interfacial energy between the copolymer and the solvent. Effect of temperature superposed on that of water content results in various morphologies, such as beads, fibers, rods, capsules, toroids, lamellae, and vesicles. The interfacial tension between the BC and the solvent increases with the increase of water content but decreases with the increase of temperature, indicating that the micellar morphologies are resulted from the competitive interplay between the temperature and the water content and always change in a direction that decreases the interfacial energy. Based on the micellar structures obtained in this work and the effects of temperature superposed on water concentration, a diagram of phase evolution of different micellar morphologies is illustrated here, covering the temperature range from 20 °C to 80 °C and the water content changing from 20 vol% to 35 vol%. For the investigation of BC composition, morphological transition of vesicle-to-fiber, for high PS length, is observed as compared with bead-to-capsule for low PS length, as the temperature changes from 20 °C to 80 °C. Our research complements the protocols to control over the morphologies and the phase diagram describing P4 VP-b-PS-b-P4 VP micellar nanostructures in aqueous solution.
基金the Natural Science Foundation of Tianjin(No.06YFJMJC05000).
文摘By hydrolysing titanium isopropoxide in a long hydrocarbon chain surfactant-containing solution, TiO2 fine particles with a diversity of well-defined morphologies was synthesized in this study by a hydrothermal route. The structural change during the formation process was monitored by scanning electron microscopy, transmission electron microscopy and X-ray diffraction analysis. TiO2 with various morphologies such as particle, sheet, rod, tube and flower-like shape was obtained by carefully controlling the preparation conditions. The experimental results show that the pH value is crucial for shape control of the produced TiO2 because it can change the charge state of the surfactant in the solution and the adsorption potential of the surfactant on the TiO2 surface. The shape evolvement of anatase TiO2 was elucidated by quenching the reaction at different stage and the formation mechanism of different shaped TiO2 was suggested.
基金financial support by the National Natural Science Foundation of China(21975038,21606039,and 51661135021)the Swiss National Science Foundation(IZLCZ2_170177)+3 种基金the Fundamental Research Funds for the Central Universities(DUT17JC39)the Swedish Foundation for Strategic Research(SSF)the Swedish Energy Agencythe Knut and Alice Wallenberg Foundation。
文摘All-inorganic cesium lead bromide(CsPbBr3)perovskite is attracting growing interest as functional materials in photovoltaics and other optoelectronic devices due to its superb stability.However,the fabrication of high-quality CsPbBr3 films still remains a big challenge by solution-process because of the low solubility of the cesium precursor in common solvents.Herein,we report a facile solution-processed approach to prepare high-quality CsPbBr3 perovskite films via a two-step spin-coating method,in which the Cs Br methanol/H2 O mixed solvent solution is spin-coated onto the lead bromide films,followed by an isopropanol-assisted post-treatment to regulate the crystallization process and to control the film morphology.In this fashion,dense and uniform CsPbBr3 films are obtained consisting of large crystalline domains with sizes up to microns and low defect density.The effectiveness of the resulting CsPbBr3 films is further examined in perovskite solar cells(PSCs)with a simplified planar architecture of fluorine–doped tin oxide/compact Ti O2/CsPbBr3/carbon,which deliver a maximum power conversion efficiency of 8.11%together with excellent thermal and humidity stability.The present work offers a simple and effective strategy in fabrication of high-quality CsPbBr3 films for efficient and stable PSCs as well as other optoelectronic devices.
基金the National Natural Science Foundation of China(No.51802266)Shaanxi’s Key Project of Research and Development Plan(No.2021GY-217)+1 种基金the Research Funds for Interdisciplinary Subject of NWPU(No.19SH0304)the Fundamental Research Funds for the Central Universities(No.3102017jc01001)。
文摘Transition metal dichalcogenides(TMDs)have emerged as a promising electrocatalyst for hydrogen evo-lution reaction(HER)due to its excellent conductivity and abundant electrocatalytic active sites of its edges.TMDs nanowall can expose abundant of edges so that they tend to show better catalytic performance for hydrogen evolution reaction.Herein,PtSe_(2) nanowall films with morphology controlled at centimeters level are synthesized by selenizing Pt film.The dynamic and thermodynamics of selenation reaction are investigated.The nanowall structure can be obtained by controlling the growth temperature,and the thickness of nanowall can be tuned by the original thickness of Pt film.The Pt atoms can be rearranged into ordered distribution at 550℃ and can be induced to well-ordered PtSe_(2) nanowalls finally.The well-ordered PtSe_(2) nanowall films show excellent HER performance,with an overpotential of 0.3 V at-10 mA·cm^(-2) and a Tafel slope of~52 mV·dec^(-1).This work demonstrates the great potential of activated 2D PtSe_(2) as an ultrathin film catalyst for the HER,which is valuable to provide instruction and afford experience for further application at industrial level.
基金Funded by Shan’xi Educational Committee(No.17JK0395)
文摘Al2O3 powders with different morphologies,namely fibrous,sheet-like,and spherical,were prepared by the hydrothermal-thermolysis method.Subsequently,polycrystalline,transparent cerium doped lutetium aluminum garnet（Lu3Al5O（12）：Ce^3＋）green phosphors were synthesized by high temperature solidstate method using commercial lutetium（III）oxide,cerium（III）oxide,and as-prepared Al2O3 powders with different morphologies.The phases,morphologies,and photoluminescent properties of the prepared phosphors were investigated by X-ray diffraction（XRD）,scanning electron microscopy（SEM）,and photoluminescence spectroscopy（PL）.Moreover,the influences of the morphologies ofα-Al2O3 on the types of crystal structure,morphologies,and photoluminescent properties of LuAG：Ce^3＋green phosphors were investigated.The results indicated that the morphologies and particle sizes of theα-Al2O3 powders could be controlled by the additives and parameters.Notably,the sphericalα-Al2O3 powders with good dispersibility were found to be the excellent base materials of LuAG：Ce^3＋green phosphors for white light emitting diodes.
基金the Key Scientific and Technological Project of Sichuan Province(No.03GG021-002)
文摘Using SrC12-6H2O and Na2CO3 as the main raw materials and adding different complexons as modifiers with simple co-precipitation method, SrCO3 crystals with distinct morphologies like spherical, bundle-like, overlapping plate-like, hexagonal star-like, dumbbell-like, etc. can be synthesized in the ethanol-water mixtures. The samples were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and Fourier transform infrared spectrograph （FT-IR）. The interrelated effect mechanism is presented in the end. Results show that the modifier carboxyl groups play a significant role in controlling the SrCO3 crystal morphologies, which can alter the crystal growth unit （Sr^2＋） supply mode and induce the crystal formation with the morphologies matching their spatial configurations.
文摘Four shapes of Cu2O particles as sphere,cube,truncated octahedron and octahedron were prepared via glucose reduction of Cu(Ⅱ)under alkaline condition.The products were characterized by XRD and SEM.The effects of the precursor(CuO,Cu(OH)2), reaction temperature and glucose concentration on morphology of Cu2O particles were investigated,and the mechanism of morphology control was discussed on the basic theory of crystal nucleation and growth.It is found that the Cu+supersaturation is remarkably influenced by the precursor kind,reaction temperature and glucose concentration,and the morphology of Cu2O particles can be controlled by the Cu+supersaturation.
基金funded by the National Natural Science Foundation of China (41101348)
文摘The plane form of a gully can provide a basis for evaluating the gully volume and erosion rate, acting process, and evolutionary stage. For describing the planar characteristics of a permanent gully and understanding their controlling factors, this study, utilizing a total station and GPS RTK, measured the shoulder lines and channel curves of 112 gullies in six sites of the Yuanmou Dry-hot Valley and then mapped them by Arc GIS software and calculated nine parameters. The results showed that the channel lengths range from 10.88 to 249.11 m; the widths range from 6.20 to 40.99 m; the perimeters range from 54.11 to 541.67 m; the gully areas range from 153.02 to 6,930.30 m2; the left-side areas range from 92.93 to 4,027.20 m2; and the right-side areas range from 63.65 to 3,539.77 m2. The slightly sinuous and straight gullies account for 73.21% of the total gullies; the quantity of the right skewed gullies is 8.93% greater than that of the left skewed ones based on the symmetry ratio; the shape ratios range from 1.12 to 1.40 and the morphology ratios from 0.038 to 1.294; the fractal dimension is 1.192. Gullies in different sites have diverse planar characteristics. Except for the symmetry index, which was close to a negatively skewed distribution, all of the other parameters had the characteristic of positively skewed distribution. The gully area is related to the length and width, but the gully length has a weak correlation with the width. The evolutionary stage, topographic conditions, strata, soil properties, and piping erosion played very important roles in the gully planar morphology. This study could provide useful information for controlling gully erosion and safeguarding human habitation and engineering buildings.
基金supported by the National Natural Science Foundation of China(21666027)Program for New Century Excellent Talents in University(NCET-12-1017)+4 种基金the Natural Science Foundation of Inner Mongolia Autonomous Region(2016JQ02)Key Laboratory of Coal-based CO2 Capture and Geological Storage(Jiangsu Province,China University of Mining and Technology,2016A06)the Program for Grassland Excellent Talents of Inner Mongolia Autonomous Regionthe Inner Mongolia Science and Technology Key Projectstraining plan of academic backbone in youth of Inner Mongolia University of Technology
文摘We here report a new CO_2 capture and storage method that converts CO_2 into a novel alkyl carbonate salt, denoted as CO_2 SM, by a system consisting of equimolar 1,4-butanediol(BDO) and 1,2-ethylenediamine(EDA). This novel CO_2 SM was then used to prepare BaCO_3 crystals through a simple and fast hydrothermal synthesis under mild conditions. The CO_2 SM was both the source of CO_2 and the modifier to regulate the nucleation and growth of BaCO_3 crystals. The morphology of the BaCO_3 crystals could be tuned from rod to shuttle by adjusting the key influencing factors, including CO_2 SM concentration, mineralization temperature, and mineralization time. A possible mechanism for the synthesis of BaCO_3 crystals from the CO_2 SM was also presented. After the BaCO_3 crystals were isolated, the filtrate of the hydrothermal reaction could be recycled to again absorb CO_2 and prepare BaCO_3 crystals of the same polymorph. This novel approach appears promising for preparing well-formed metal carbonates.
基金This work was financially support by the Japan Society for the Promotion of Science(JSPS)Grant-in-Aid for Scientific Research(KAKENHI)(No.20H00297 and Innovative Areas No.JP16H06439)the Cooperative Research Program of Dynamic Alliance for Open Innovations Bridging Human,Environment and Materials in the“Network Joint Research Center for Materials and Devices”.
文摘Hydrogen is a promising renewable energy source for fossil-free transportation and electrical energy generation.However,leaking hydrogen in high-temperature production processes can cause an explosion,which endangers production workers and surrounding areas.To detect leaks early,we used a sensor material based on a wide bandgap aluminum nitride(AlN)that can withstand a high-temperature environment.Three unique AlN morphologies(rod-like,nest-like,and hexagonal plate-like)were synthesized by a direct nitridation method at 1400℃usingγ-AlOOH as a precursor.The gas-sensing performance shows that a hexagonal plate-like morphology exhibited p-type sensing behavior and showed good repeatability as well as the highest response(S=58.7)toward a 750 ppm leak of H2 gas at high temperature(500°C)compared with the rod-like and nest-like morphologies.Furthermore,the hexagonal plate-like morphology showed fast response and recovery times of 40 and 82 s,respectively.The surface facet of the hexagonal morphology of AlN might be energetically favorable for gas adsorption–desorption for enhanced hydrogen detection.
基金National Natural Science Foundation of China (No.51572185)Natural Science Foundation of Shanxi Province (No.2014011016-4)+4 种基金Key R&D program of Shanxi Province (International Cooperation,No.201903D421079) for the financial supportsupported by Shanxi Province Technology Foundation for Selected Overseas Chinese ScholarResearch Project Supported by Shanxi Scholarship Council of ChinaCollege Student Innovation Program of Shanxi (Nos.2017550,2018081)National College Student Innovation and Entrepreneurship Training Program (No.201910112002)。
文摘Organic amines are important solvent and raw material in laboratory and industry,as well as releasing from cigarette smoke.It is significant to detect low-concentration amines for environment and public health.Here we reported that as-synthesized zinc oxide is an effective electrode material of electrochemical sensor for the detection of amines.The characterization results reveal that the ZnO morphologies experienced a change from hexagonal bowl-like microparticles,cones,prisms to nanoparticles by adjusting the reaction time,temperature,solvents and additives.Interestingly,ZnO material possessing hexagonal shapes and different sizes exhibits distinct electrochemical response in various amines solution,suggesting that there is a better dependent relationship between different morphological ZnO and amines detection.Particularly,regular hexagonal ZnO nanotablets exhibit a detectable electrochemical response and selectivity to ammonia,implying it can be serve as electrode material for highly effective detection of organic amines.
基金financially supported by the National Natural Science Foundation of China (Nos.51401001, 51371011,513 31003)the International S&T Cooperation Program of China (No.2015DFG52020)。
文摘Cobalt nanowires with different shapes and sizes were synthesized by reduction of carboxylate salts of Co^(Ⅱ) in 1,2-butanediol using a solvothermal chemical process.The well-crystallized Co nanowires with hexagonal closepacked(hep) phase are observed and the(002) crystalline direction is along the long axis of nano wires.The morphology control is strongly dependent on the reaction parameters.By varying the amount of capping agent in proper ranges,the effect of reaction parameters on controlling the size and shape of Co nanowires is demonstrated.With the amount of capping agent increasing,the aspect ratio of Co nanowires increases remarkably.However,the magnetic measurement of cobalt nanowires shows that the coercivity of the Co nanocrystals does not increase with the increase in aspect ratio monotonously,which suggests that the tip shape and micros tructure also play an important role in the magnetization reversal process of the Co nanocrystals,and the aspect ratio plays a much less role as the ratio value exceeds 11.To further understand the effect of size on the magnetic properties in the Co nanowires,micromagnetic simulations were performed,which confirms that the magnetic properties are barely affected by the aspect ratio larger than 10.The highest coercivity of624 kA·m^(-1) is obtained for ellipsoid nano wires with a mean length of 200 nm,which also displays a strong magnetic anisotropy.As a result,the highest energy product of the wires reaches 248 kJ·m^(-3).
基金National Natural Science Foundation of China(22078039)Science Fund for Creative Research Groups of the National Natural Science Foundation of China(22021005)+1 种基金National Key Research and Development Program of China(2023YFB3810700)the Fundamental Research Funds for the Central Universities(DUT22LAB602)。
文摘Preferential orientation control of metal—organic framework(MOF)films is advantageous for maximizing pore uniformity and minimizing grain-boundary defects.Nonetheless,the preparation of MOF films with both in-plane and out-of-plane orientations remains a grand challenge.In this study,we reported the preparation of three-dimensionally oriented MIL-96 layers through combining morphology control of MIL-96 seeds with addition of polyvinylpyrrolidone surfactants and arachidonic acids.The three-dimensionally oriented MIL-96 film was readily obtained through in-plane epitaxial growth.It is anticipated that the aforementioned protocol can be effective for obtaining diverse MOF films with a three-dimensionally oriented organization.
基金financially supported by the Sichuan Science and Technology Program(Grant Nos.2023YFH0087,2023YFH0085,2023YFH0086,and 2023NSFSC0990)State Key Laboratory of Polymer Materials Engineering(Grant Nos.sklpme2022-3-02 and sklpme2023-2-11)+1 种基金Tibet Foreign Experts Program(Grant No.2022wz002)supported by the King Abdullah University of Science and Technology(KAUST)Office of Research Administration(ORA)under Award Nos.OSR-CARF/CCF-3079 and OSR-2021-CRG10-4701.
文摘Organic photovoltaics(OPVs)need to overcome limitations such as insufficient thermal stability to be commercialized.The reported approaches to improve stability either rely on the development of new materials or on tailoring the donor/acceptor morphology,however,exhibiting limited applicability.Therefore,it is timely to develop an easy method to enhance thermal stability without having to develop new donor/acceptor materials or donor–acceptor compatibilizers,or by introducing another third component.Herein,a unique approach is presented,based on constructing a polymer fiber rigid network with a high glass transition temperature(T_(g))to impede the movement of acceptor and donor molecules,to immobilize the active layer morphology,and thereby to improve thermal stability.A high-T_(g) one-dimensional aramid nanofiber(ANF)is utilized for network construction.Inverted OPVs with ANF network yield superior thermal stability compared to the ANF-free counterpart.The ANF network-incorporated active layer demonstrates significantly more stable morphology than the ANF-free counterpart,thereby leaving fundamental processes such as charge separation,transport,and collection,determining the device efficiency,largely unaltered.This strategy is also successfully applied to other photovoltaic systems.The strategy of incorporating a polymer fiber rigid network with high T_(g) offers a distinct perspective addressing the challenge of thermal instability with simplicity and universality.
基金the financial support from the National Natural Science Foundation of China(Nos.52321165650,52127806)the Fundamental Research Funds for the Central Universities(Grant Nos.226-2024-00005 and 226-2024-00056).
文摘As an emerging photovoltaic technology,organic solar cells(OSCs)have attracted extensive attention in recent years due to the advantages of light weight,flexibility,semi-transparency,and potential for roll-to-roll device fabrication.Currently,state-of-the-art OSCs have achieved over 20%power conversion efficiency(PCE),indicating their bright application prospects.Thus,stability becomes a critical issue for the commercialization of OSCs.In practical environments,light and heat are the main factors affecting the stability of OSCs.In this review,we first summarize the key degradation routes induced by thermal and light stresses.Then,recent strategies to enhance thermo-and photostability of OSCs are reviewed,focusing on material design and morphology control.Finally,some suggestions are provided for the development of next-generation OSCs with high efficiency and excellent stability.
文摘Ag3PO4 is found to be a highly efficient photocatalyst and receives great attention. The high activity of the photocatalyst is credited to the intrinsic electronic structure. The morphology control and nano-composite fabrication are used to improve the performance and practicability. This paper reviews the structure, properties and some theoretical aspects of Ag3PO4 single crystal. Also, the major strategies, namely the morphology control and hetero-nanostructure construction, as ways to improve the performance of Ag3PO4-based photocatalysts, are summarized with the aid of some typical instances.
基金This research was supported by National Natural Science Foundation of China(21706132 and 21976093)Jiangsu Provincial Specially Appointed Professors Foundation,The Startup Foundation for Introducing Talent of NUIST.
文摘The efficient utilization of photocatalytic technology is essential for clean energy.Bismuth-based multimetal oxides(Bi_(2)WO_(6),Bi_(2)MoO_(6),BiVO_(4)and Bi_(4)Ti_(3)O_(12))have aroused widespread attention as a visible light responsive photocatalyst for hydrogen evolution due to their low cost,nontoxicity,modifiable morphology,and outstanding optical and chemical properties.Nevertheless,the photocatalytic activities of pure materials are unsatisfactory because of their relative small specific surface area,poor quantum yield,and the rapid recombination of photogenerated carriers.Therefore,some modification strategies,including morphological control,semiconductor combination,doping,and defect engineering,have been systematically studied to enhance photocatalytic H_(2)evolution activity in the past few years.Herein,we summarize the recent research progress on bismuth-based photocatalysts,pointing out the prospects,opportunities and challenges of bismuth-based photocatalysts.Eventually,we aims to put forward valuable suggestions for designing of bismuth-based photocatalysts applied in hydrogen production on the premise of consolidating the existing theoretical basis of photocatalysis.
基金This work was financially supported by the National Natural Science Foundation of China (Nos. 50272049 and 20473059).
文摘BaCO3 whiskers exhibiting different morphologies were fabricated by a simple precipitation reaction of barium ch/oride with sodium carbonate in the absence and presence of poly-（styrene-alt-maleic acid） （PSMA） as a crystal growth modifier at room temperature. The as-prepared products were characterized by scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, and X-ray diffraction （XRD）. The influences of experimental parameters on the size and morphology of BaCO3 whiskers were investigated and discussed. It was found that the as-prepared BaCO3 whiskers are single crystals with diameter ranging from 100 to 300 run, and grow along the crystallographic a-axis or [100] direction. BaCO3 whiskers with different morphologies, such as branching and dendritic structure, can be obtained depending on the experimental conditions. With increasing PSMA concentration, the diameter of BaCO3 whiskers decreases.
