An novel method on preparation of precursor solution for solvent separation of molybdenum （Mo） and tungsten （W） by hydrogen peroxide （H2O2）-complexation from the ammonium tungstate solution containing high Mo wa...An novel method on preparation of precursor solution for solvent separation of molybdenum （Mo） and tungsten （W） by hydrogen peroxide （H2O2）-complexation from the ammonium tungstate solution containing high Mo was studied. The precursor solution was obtained via evaporation deamination and H202-complex transformation processes. Then it was extracted with a mixture extractant of tri-alkyl phosphine oxide （TRPO） and tributyl phosphate （TBP） to separate Mo and W. The results indicated that the evaporation deamination complex method reduced the acid consumption by more than 90% in comparison with the traditional directly acid regulation complex method. The transformation rates of W and Mo were higher than 95% and the decomposition rate of H202 was less than 15% at a 1.8-1.9 times H202 dosage, 45-50 ℃, initial pH of 1.80-1.90, and transformation volume ratio of 100% for 60 min in the H2O2-complexation transformation process. The minimum extraction rate of W was 2%, the maximum extraction rate of Mo was 82.6% and the highest separation coefficient was 76.7 in a single-stage extraction.展开更多
Epitaxial YBCO films were deposited on （100） LaAlO3 single-crystal substrates by metalorganic deposition of metal trifluoroacetate precursors with different concentrations. All the YBCO films have Tc around 91 K and...Epitaxial YBCO films were deposited on （100） LaAlO3 single-crystal substrates by metalorganic deposition of metal trifluoroacetate precursors with different concentrations. All the YBCO films have Tc around 91 K and Jc excess 2 MA/cm^2 at 77 K in zero field. XRD θ-2θscans show all the films have c-axis normal orientation. The FWHM （full width at half-maximum intensity） values of X-ray ω-scans of （005） reflection are 0.379°, 0.283°, and 0.543° for the YBCO thin films deposited with precursor solution concentrations of 1.52, 1.0, and 0.75 mol/L, respectively. With the concentration of the precursors decreasing, the thickness of the films decreases linearly. SEM micrographs show that porosities in the films become bigger with the precursor solution concentration decreasing. The big porosities in the film with the lowest concentration precursor deteriorate the superconducting property and make it have a wider superconducting transition and a lower Jc.展开更多
Formamidinium lead triiodide(FAPbI_(3))is a research hotspot in perovskite photovoltaics due to its broad light absorption and proper thermal stability.However,quite a few researches focused on the stability of the FA...Formamidinium lead triiodide(FAPbI_(3))is a research hotspot in perovskite photovoltaics due to its broad light absorption and proper thermal stability.However,quite a few researches focused on the stability of the FAPbI_(3) perovskite precursor solutions.Besides,the most efficient FAPbI_(3) layers are prepared by the spin-coating method,which is limited to the size of the device.Herein,the stability of FAPbI_(3) perovskite solution with methylammonium chloride(MACl)or cesium chloride(CsCl)additive is studied for preparing perovskite film through an upscalable blade-coating method.Each additive works well for achieving a high-quality FAPbI_(3) film,resulting in efficient carbon electrode perovskite solar cells(pero-SCs)in the ambient condition.However,the perovskite solution with MACl additive shows poor aging stability that noα-FAPbI_(3) phase is observed when the solution is aged over one week.While the perovskite solution with CsCl additive shows promising aging stability that it still forms high-quality pureα-FAPbI_(3) perovskite film even the solution is aged over one month.During the solution aging process,the MACl could be decomposed into methylamine which will form some unfavored intermediated phase inducingδ-phase FAPbI_(3).Whereas,replacing MACl with CsCl could effectively solve this issue.Our founding shows that there is a great need to develop a non-MACl FAPbI_(3) perovskite precursor solution for cost-effective preparation of pero-SCs.展开更多
Pb0.97La0.02Zr0.95Ti0.05O3(PLZT)antiferroelectric thick films derived from different precursor solution concentrations are prepared on platinized silicon substrates by sol-gel processing.The films present polycrystall...Pb0.97La0.02Zr0.95Ti0.05O3(PLZT)antiferroelectric thick films derived from different precursor solution concentrations are prepared on platinized silicon substrates by sol-gel processing.The films present polycrystalline perovskite structure with a(100)preferred orientation by X-ray diffraction(XRD)analysis.The antiferroelectricity of the films is confirmed by the double hysteresis behaviors of polarization and double-bufferfly response of dielectric constant under the applied electrical field.Antiferroelectric properties and dielectric constant are improved while the polarization characteristic values are reduced with the increase of precursor solution concentration.The films at higher precursor solution concentration exhibit excellent dielectric properties.展开更多
Colloids are a vital component of perovskite precursor solutions(PPSs),significantly influencing the quality of perovskite film formation.Despite their importance,a comprehensive understanding of these colloids remain...Colloids are a vital component of perovskite precursor solutions(PPSs),significantly influencing the quality of perovskite film formation.Despite their importance,a comprehensive understanding of these colloids remains elusive.In this work,we explored the colloidal compositions of two distinct PPS types:the monomer-mixing dissolution(MMD)and the pre-synthesized perovskite single crystal redissolution(SCR).We have uncovered a new dissolution chemical equilibrium mechanism where the transition from mixed monomers to the 3C cubic phase(α-phase)involves a reversible transformation.Our findings indicate that although colloidal size significantly affects the nucleation during perovskite crystallization,the composition of the colloids plays a more crucial role.The MMD method yields poly Pb-I·solvent clusters while the colloids derived from the SCR approach produce hexagonal lead-halide-based perovskite phase clusters.These divergent colloidal compositions lead to markedly different impacts on the perovskite film formation process.Notably,hexagonal-phase colloids act as favorable nucleation sites,promoting the generation of theα-phase perovskite films with larger grains,more homogeneous phases,and fewer defects.This work demonstrates the importance of tailoring colloidal compositions and provides theoretical insights into the beneficial effects of redissolving perovskite in forms such as powder,microcrystals,and single crystals.展开更多
At present,the development of perovskite solar cells(PSCs)is progressing rapidly,but the issue of poor stability remains a significant challenge.Achieving a stable precursor solution is crucial for the large-scale pro...At present,the development of perovskite solar cells(PSCs)is progressing rapidly,but the issue of poor stability remains a significant challenge.Achieving a stable precursor solution is crucial for the large-scale production of high-quality PSC films.In this study,we successfully developed a strategy to improve the long-term stability of the precursor solution and improve device performance by employing 1-n-butyl-3-methylimidazolium di-n-butyl phosphate(BMIMBP)as an anti-aging additive.The BP−component inhibits the reactivity of I−and formamidinium ion through multiple chemical bonds,thereby stabilizing the precursor solution.In addition,the BMIM+component,which contains an amino group,can form two-dimensional perovskite internally,further enhancing the device stability.This strategy provides valuable guidance for achieving long-term stability in solar cells.展开更多
The molecular structures of metal precursors in the impregnating solution were designed so as to prepare efficient Ni Mo/Al_2O_3 hydrodesulfurization(HDS) catalysts. At first, five typical impregnating solutions were ...The molecular structures of metal precursors in the impregnating solution were designed so as to prepare efficient Ni Mo/Al_2O_3 hydrodesulfurization(HDS) catalysts. At first, five typical impregnating solutions were designed; the existing metal precursors, such as [Mo4(citrate)2O11]^(4-)-like, [P2Mo18O62]^(6-)-like and [P2Mo5O23]^(6-)-like species in the solutions were confirmed by laser Raman spectroscopy(LRS). The UV-Vis spectra results indicated that the solutions containing both phosphoric acid and citric acid could change the existing form of nickel species. Five corresponding Ni Mo/Al_2O_3 catalysts were prepared by the incipient wetness impregnation method. The LRS analysis results of dried catalysts showed that the above metal precursors could be partly retained on alumina support after impregnation and drying, although the interface reaction between different metal precursors and alumina support unavoidably took place. Then the catalysts were sulfided and characterized by N2 physisorption, TEM and XPS analyses. The results showed that different metal precursors in impregnating solution could mainly result in the difference in both the morphology of(Ni)Mo S2 slabs and the promoting effect of Ni species. The catalyst prepared mainly with [P2Mo5O23]^(6-)-like species used as precursors exhibited worse dispersion of(Ni)Mo S2 slabs and lower ratio of Ni–Mo–S active phases than the one with [Mo4(citrate)2O11]^(4-)-like species. Promisingly, the catalyst prepared with co-existing [Mo4(citrate)2O11]^(4-)-like, [P2Mo18O62]^(6-)-like and [P2Mo5O23]^(6-)-like species showed better hydrodesulfurization activity for 4,6-DMDBT thanks to its more well-dispersed Ni–Mo–S active phases.展开更多
The basis of the hydrophobicity of lanthanide rare earth oxides(REOs)has been the subject of considerable debate.To explore this question,the wetting behaviors and surface compositions of hierarchicallystructured Yb_(...The basis of the hydrophobicity of lanthanide rare earth oxides(REOs)has been the subject of considerable debate.To explore this question,the wetting behaviors and surface compositions of hierarchicallystructured Yb_(2)o_(3)(one of the REOs)coatings and non-REO Al_(2)o_(3)coatings deposited via solution precursor plasma spray process were investigated in this work.The Yb_(2)o_(3)coatings were subjected to a number of post-deposition treatments including vacuum(1-15 Pa)treatment,Ar-plasma treatment,heat treatment(400℃),long-time air exposure and ultra-high vacuum(1×10^(-7)Pa)treatment.Subsequent characterization showed that different post-deposition treatments resulted in different wetting behavior for the Yb_(2)o_(3)coatings which correlated with the content of hydrocarbon on the surface.Yb_(2)o_(3)coatings exhibited reversible transitions between superhydrophobicity after vacuum treatment and superhydrophilicity after Ar-plasma or heat treatment,linked to hydrocarbon adsorption onto and desorption from the surface.Yb_(2)o_(3)coatings after long-time air exposure and ultra-high vacuum treatment both remained hydrophilic and showed a smaller hydrocarbon content than coatings after vacuum treatment.Al_(2)o_(3)coatings with hierarchical surface structures similar to the Yb_(2)o_(3)coatings showed an increase in WCA to only-170 after the same vacuum treatment,indicating the REO has a much higher affinity for hydrocarbon adsorption than Al_(2)o_(3),and that the content of hydrocarbon adsorbed on the surface of the REO determined the wetting behavior.展开更多
Organic-inorganic lead halide perovskites represent a group of materials with diverse structures and promising optical/optoelectronic properties.The performance of perovskite based solar cells relies tremendously on t...Organic-inorganic lead halide perovskites represent a group of materials with diverse structures and promising optical/optoelectronic properties.The performance of perovskite based solar cells relies tremendously on the structure/properties of the absorber.The physicochemical properties of the perovskite active layer depend on the substrate,preparation methods,environments and the starting materials.In this study,we investigated the effects of starting materials in the precursor solution on the physicochemical properties of the resulting one-step spin coated MA_(0.8)FA_(0.2)PbI_(3-y)Br_(y) film and the photovoltaic performance of the corresponding inverted(p-i-n)perovskite solar cells.Two precursor solutions containing exactly the same atom stoichiometry were prepared from two different groups of starting materials(Group A:CH_(3)NH_(3)I,CH(NH_(2))_(2)I,CH_(3)NH_(3)Br,and PbI_(2);Group B:CH_(3)NH_(3)I,CH(NH_(2))_(2)I,PbI_(2) and PbBr_(2)).The MA_(0.8)FA_(0.2)PbI_(3-y)Br_(y) films(A1 and A2)prepared from the A precursor solution had better photovoltaic performances compared to those(B1 and B2)obtained from the B precursor solution for the same y values.The stoichiometry of the film to achieve the best photovoltaic performance(the corresponding cell has the highest efficiency)is not the same for the A-group(prepared from the A precursor solution)and B-group films(prepared from the B precursor solution).The photovoltaic performance of the perovskite film is directly correlated to the crystallinity,morphology and defect sites of the film as evidenced by GIXRD,scanning electron microscopy(SEM)and transient photoluminescence(TRPL)data.The morphology of the mixed-halide perovskite films depends on the homogeneity of the halide stoichiometries.The A-group films with more possible halide stoichiometries have better crystallinity and continuity compared to those of the B-group films,probably due to the difference in the crystallization rates for the two group perovskite films.Therefore,for preparing mixed-halide perovskites with the same average halide stoichiometry,starting materials that can produce perovskite films with more halide stoichiometries are a better choice.展开更多
Recently,perovskite solar cells(PSCs) have flourished,and their power conversion efficiency(PCE) has increased from the initial 3.8% to 25.2% in 2019,which is an unprecedented advance.However,usually high-efficiency a...Recently,perovskite solar cells(PSCs) have flourished,and their power conversion efficiency(PCE) has increased from the initial 3.8% to 25.2% in 2019,which is an unprecedented advance.However,usually high-efficiency and stable PSCs are small-area devices prepared by spin coating.This method is not suitable for the preparation of large-area devices in commercialization.Therefore,there is an urgent need to develop new materials and methods for the scalable fabrication of PSCs.In this review,we first describe the common small-area PSCs preparation methods,understand the nucleation and crystal growth kinetics of perovskite,and analyze the reasons that hinder the development of small-area devices to large-area devices.Next,in order to meet the challenges of PSC’s scalable fabrication,we summarize and analyze four strategies:scaling up precursor solutions,scalable deposition methods for large-area films,scaling up charge-transport layers and back electrodes,developing solar modules.Finally,challenges and prospects are proposed to help researchers prepare high-efficiency large-area PSCs.展开更多
Selective-controlled structure and shape of CeVO4 nanocrystals were successfully synthesized via a hydrothermal method from Na3VO4·12H2O and Ce（NO3）3·6H2O.The resulting products were characterized by X-ray...Selective-controlled structure and shape of CeVO4 nanocrystals were successfully synthesized via a hydrothermal method from Na3VO4·12H2O and Ce（NO3）3·6H2O.The resulting products were characterized by X-ray powder diffraction （XRD）,field emission scanning electron microscopy （FESEM） and energy dispersive spectroscopy （EDS）.The influence of hydrothermal temperature,precursor solution concentration on the crystal and morphology of products were further studied.The results showed that the as-synthesized products exhibited pure single-crystal CeVO4 nanoparticles with tetragonal structure.The hydrothermal temperature and precursor solution concentration had important effects on the formation of CeVO4 nanoparticles.Furthermore,the growth mechanism of CeVO4 nanoparticles was explained with Ostwald ripening mechanism.展开更多
Cu-rich cell boundary phase is difficult to precipitate evenly,resulting in a generally poor demagnetization curve squareness for Fe-rich Sm_(2)Co_(17)-type magnet,which is a key factor limiting the further improvemen...Cu-rich cell boundary phase is difficult to precipitate evenly,resulting in a generally poor demagnetization curve squareness for Fe-rich Sm_(2)Co_(17)-type magnet,which is a key factor limiting the further improvement of magnetic energy product.In this study,we report that nanoscale strip-like ordered micro-domains distributed in1:7H disordered matrix phase of the solid solution precursor is a new factor significantly affecting the precipitation and distribution of the cell boundary phase.Long strip-like and continuous micro-twin structure with twin boundaries neatly perpendicular to the C-axis is observed after sintering treatment.After solution treatment,sequential and long strip-like micro-twins gradually transform into disordered state along the basal plane,forming narrow disordered 1:7H(TbCu_(7)-type structure)phase between the separated strip-like ordered micro-domains.This disordering transformation takes place via broken down of the long strip-like ordered micro-domains,which is accomplished by narrowing along the width direction followed by reduction of the length.Furthermore,a new model revealing the effect of the ordered micro-domains on the formation of the cell boundary phase is proposed.Antiphase boundaries enriched in Cu have already existed in the precursor with long strip-like ordered micro-domains.Therefore,the Cu-rich cell boundary phase acting as strong pinning centers cannot be precipitated homogeneously and distributed continuously after aging,resulting in a poor demagnetization curve squareness of Sm_(2)Co_(17)-type magnet.Our results indicate that significant broken down of the nanoscale ordered micro-domains in solution precursor is the key factor improving the distribution of cell boundary phase in Sm_(2)Co_(17)-type magnets.展开更多
High quality perovskite films were fabricated from different precursor solutions containing a certain proportion of different hydrogen halides.An anti-solvent,toluene,was used here to isolate an intermediate from the ...High quality perovskite films were fabricated from different precursor solutions containing a certain proportion of different hydrogen halides.An anti-solvent,toluene,was used here to isolate an intermediate from the perovskite precursor solution to reveal the impact of the hydrogen halides on the crystallization of perovskite films.From the Fourier transform infrared spectra we found that the stretch vibration of C=O for pure N,N-dimethylformamide(DMF)appeared at 1663 cm^(-1),which was shifted to a smaller wavenumber while reacting DMF with CH_(3)NH_(3)I(MAI)+PbI_(2)and MAI+PbI_(2)+HX(X=Cl,Br,I).Moreover,the appearance of X-ray diffraction(XRD)peaks at low angles(near 8 degrees)as well as some small angle shift showed that the MAI-PbI_(2)-DMF-xHX(X=Cl,Br,I)intermediate was formed,which benefits perovskite crystallization because the formation of the intermediate will avoid a rapid reaction between MAI and PbI_(2).What's more,the solubility of the precursor can be improved by adding hydrogen halides.By adding a certain amount of hydrogen halide into the one-step perovskite precursor solution we can obtain pin-hole free and almost no defect films.Transient absorption(TA)was carried out to investigate the charge recombination in intrinsic perovskite films and perovskite devices,giving some reasonable interpretations.展开更多
Perovskite solar cells(PSCs)are promising next-generation photovoltaics due to their unique optoelectronic properties and rapid rise in power conversion efficiency.However,the instability of perovskite materials and d...Perovskite solar cells(PSCs)are promising next-generation photovoltaics due to their unique optoelectronic properties and rapid rise in power conversion efficiency.However,the instability of perovskite materials and devices is a serious obstacle hindering technology commercialization.The quality of perovskite films,which is an important prerequisite for long-term stable PSCs,is determined by the quality of the precursor solution and the post-deposition treatment performed after perovskite formation.Herein,we review the origin of instability of solution-processed PSCs from the perspectives of the precursor solutions and the perovskite films.In addition,we summarize the recent strategies for improving the stability of the perovskite films.Finally,we pinpoint possible approaches to further advance their long-term stability.展开更多
A perovskite material CsAg_(2)Sb_(2)I_(9)was developed by dissolving CsI,AgI and SbI_(3)in DMF(molar ratio 1:2:2).CsAg_(2)Sb_(2)I_(9)solar cells gave a power conversion efficiency of 0.99%and a fill factor of 67.1%.Th...A perovskite material CsAg_(2)Sb_(2)I_(9)was developed by dissolving CsI,AgI and SbI_(3)in DMF(molar ratio 1:2:2).CsAg_(2)Sb_(2)I_(9)solar cells gave a power conversion efficiency of 0.99%and a fill factor of 67.1%.The morphology of a CsAg_(2)Sb_(2)I_(9)film was affected significantly by the CsI content in the precursor solution.展开更多
We demonstrate in this work that N-methyl-2-pyrrolidone(NMP)is a superior alternative to dimethyl sulfoxide(DMSO)as an additive in a precursor solution for the fabrication of high-quality perovskite films for solar ce...We demonstrate in this work that N-methyl-2-pyrrolidone(NMP)is a superior alternative to dimethyl sulfoxide(DMSO)as an additive in a precursor solution for the fabrication of high-quality perovskite films for solar cells.While the DMSO-assisted method always requires the films to be prepared with a low and restricted PdI_(2):DMSO ratio,NMP provides a much wider window of the PbI_(2)/NMP ratio for the preparation of high-quality perovskite films.The systematic studies on the structures of intermediates obtained with different PbI_(2)/NMP ratios reveal that only one kind of intermediate forms regardless of the Pb^(2+)/NMP ratio between 1 and 4,which is totally different from the situation of a PbI_(2)/DMSO system.But all the perovskite solar cell devices fabricated with different Pb^(2+)/NMP ratios show similar performances to their counterpart fabricated with 1:1 Pb^(2+)/DMSO.Besides the MAPbI_(3)(MA=CH_(3)NH_(3)+)system,NMP is shown to be an excellent coordinative additive for the fabrication of high-quality triple-cation(Cs^(+)/formamidinium/MA)perovskite films.展开更多
The poisonous metal lead(Pb)is one of the key limiting factors for the large-scale industrial application ofperovskite solar cells(PSCs).Here,we replaced some of the lead iodide(PbI_(2))with strontium iodide(SrI_(2))i...The poisonous metal lead(Pb)is one of the key limiting factors for the large-scale industrial application ofperovskite solar cells(PSCs).Here,we replaced some of the lead iodide(PbI_(2))with strontium iodide(SrI_(2))in the precursor solution to prepare Pb-less perovskite films and fabricate mesoscopic solar cells via theantisolvent-assisted single step method and the two-step spin-coating method.The effect of Sr substitutionon the film formation and photovoltaic properties of perovskites was illuminated by scanning electronmicroscopy(SEM),X-ray diffraction(XRD)and time-resolved photoluminescence(TRPL)analyses.The results show that,in the antisolvent-assisted single step method,Sr substitution has an impact on theformation of the intermediate phase,resulting in a lower coverage and an increased defect density ofperovskite films.When the Sr content rises from 0 to 5 mol%,the device’s power conversion efficiency(PCE)decreases from 15.22%to 6.37%.In the two-step spin-coating method,a moderate amount of SrI_(2)can change the chemical composition of the PbI_(2)precursor,resulting in less PbI_(2)and a decreased defectdensity in perovskite films.When the Sr content is 10 mol%in the PbI_(2)solution,the solar cell exhibits aconsiderable PCE of 15.52%under AM 1.5G solar illumination.展开更多
We systematically investigated the development of film morphology and crystallinity of methyl-ammonium bismuth （Ⅲ） iodide （MA3Bi2I9） through one- step spin-coating on TiO2-deposited indium tin oxide （ITO）/glass...We systematically investigated the development of film morphology and crystallinity of methyl-ammonium bismuth （Ⅲ） iodide （MA3Bi2I9） through one- step spin-coating on TiO2-deposited indium tin oxide （ITO）/glass. The precursor solution concentration and substrate structure have been demonstrated to be critically important in the active-layer evolution of the MA3Bi2I9-based solar cell. This work successfully improved the cell efficiency to 0.42% （average： 0.38%） with the mesoscopic architecture of ITO/compact-TiOdmesoscopic-TiO2 （meso-TiO2）/ MA3Bi2I9/2,2＇,7,7＇-tetrakis（N,N-di-4-methoxyphenylamino）-9,9＇spiro-bifluorene （spiro-MeOTAD）/MoO3/Ag under a precursor concentration of 0.45 M, which provided the probability of further improving the efficiency of the BiB＋-based lead-free organic-inorganic hybrid solar cells.展开更多
With the development of society,human beings are facing environmental problems and an energy crisis worldwide.In this context,photocatalysis and electrocatalysis represent promising technologies to help solving these ...With the development of society,human beings are facing environmental problems and an energy crisis worldwide.In this context,photocatalysis and electrocatalysis represent promising technologies to help solving these issues.Up to now,most of the catalysts intended for these usages are prepared via time-consuming wet-chemical approaches,e.g.hydrothermal or sol–gel methods.Moreover,these techniques produce powdery catalysts which need not only a post-filtration step,but also a shaping by a binder for their final applications,which makes the manufacturing cumbersome.Thermal spraying is currently a well-established deposition technique that is capable of elaborating a wide series of functional coatings based on all classes of materials(metals,polymers,ceramics)and featuring tunable compositions as well as micro-and nanostructures.In particular,thermal involving liquid feedstock,and more specifically precursor solutions or suspensions,have allowed generating a wide range of coating thicknesses,from the tenmicron to the submicron/nano scale,increasing thereby the possibilities for enhancing catalytic performances.The present review sets out marking researches relating to the preparation and testing of(i)some photocatalytic coatings intended for the degradation of aqueous organic pollutants and(ii)electrocatalytic coatings investigated as potential energy storage devices.This paper will not only deal with the preparation of catalysts via different thermal spray processes,but also will cover the adjustment of phase compositions and microstructures that are rendered possible when using liquid feedstock thermal spray techniques with the prospect of optimizing the catalytic performances.展开更多
基金Project(2010ZX07212-008) supported by the Major Science and Technology Program for Water Pollution Control and Treatment the China Molybdenum Co., Ltd.for financial support
文摘An novel method on preparation of precursor solution for solvent separation of molybdenum （Mo） and tungsten （W） by hydrogen peroxide （H2O2）-complexation from the ammonium tungstate solution containing high Mo was studied. The precursor solution was obtained via evaporation deamination and H202-complex transformation processes. Then it was extracted with a mixture extractant of tri-alkyl phosphine oxide （TRPO） and tributyl phosphate （TBP） to separate Mo and W. The results indicated that the evaporation deamination complex method reduced the acid consumption by more than 90% in comparison with the traditional directly acid regulation complex method. The transformation rates of W and Mo were higher than 95% and the decomposition rate of H202 was less than 15% at a 1.8-1.9 times H202 dosage, 45-50 ℃, initial pH of 1.80-1.90, and transformation volume ratio of 100% for 60 min in the H2O2-complexation transformation process. The minimum extraction rate of W was 2%, the maximum extraction rate of Mo was 82.6% and the highest separation coefficient was 76.7 in a single-stage extraction.
文摘Epitaxial YBCO films were deposited on （100） LaAlO3 single-crystal substrates by metalorganic deposition of metal trifluoroacetate precursors with different concentrations. All the YBCO films have Tc around 91 K and Jc excess 2 MA/cm^2 at 77 K in zero field. XRD θ-2θscans show all the films have c-axis normal orientation. The FWHM （full width at half-maximum intensity） values of X-ray ω-scans of （005） reflection are 0.379°, 0.283°, and 0.543° for the YBCO thin films deposited with precursor solution concentrations of 1.52, 1.0, and 0.75 mol/L, respectively. With the concentration of the precursors decreasing, the thickness of the films decreases linearly. SEM micrographs show that porosities in the films become bigger with the precursor solution concentration decreasing. The big porosities in the film with the lowest concentration precursor deteriorate the superconducting property and make it have a wider superconducting transition and a lower Jc.
基金Project supported by the Key Research and Development Program of China(Grant No.2020YFB1506400)the National Natural Science Foundation of China(Grant Nos.51922074,51673138,51820105003,and 22075194)+1 种基金the Tang Scholar,the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)Collaborative Innovation Center of Suzhou Nano Science and Technology.
文摘Formamidinium lead triiodide(FAPbI_(3))is a research hotspot in perovskite photovoltaics due to its broad light absorption and proper thermal stability.However,quite a few researches focused on the stability of the FAPbI_(3) perovskite precursor solutions.Besides,the most efficient FAPbI_(3) layers are prepared by the spin-coating method,which is limited to the size of the device.Herein,the stability of FAPbI_(3) perovskite solution with methylammonium chloride(MACl)or cesium chloride(CsCl)additive is studied for preparing perovskite film through an upscalable blade-coating method.Each additive works well for achieving a high-quality FAPbI_(3) film,resulting in efficient carbon electrode perovskite solar cells(pero-SCs)in the ambient condition.However,the perovskite solution with MACl additive shows poor aging stability that noα-FAPbI_(3) phase is observed when the solution is aged over one week.While the perovskite solution with CsCl additive shows promising aging stability that it still forms high-quality pureα-FAPbI_(3) perovskite film even the solution is aged over one month.During the solution aging process,the MACl could be decomposed into methylamine which will form some unfavored intermediated phase inducingδ-phase FAPbI_(3).Whereas,replacing MACl with CsCl could effectively solve this issue.Our founding shows that there is a great need to develop a non-MACl FAPbI_(3) perovskite precursor solution for cost-effective preparation of pero-SCs.
基金National Natural Science Foundation of China(No.60806039,No.51175483)China Postdoctoral Science Foundation Projects(No.20090461275,No.201003658)+1 种基金Shanxi Provincial Natural Science Foundation of China(No.20100210023-6)Shanxi Provincial Young Leaders on Science
文摘Pb0.97La0.02Zr0.95Ti0.05O3(PLZT)antiferroelectric thick films derived from different precursor solution concentrations are prepared on platinized silicon substrates by sol-gel processing.The films present polycrystalline perovskite structure with a(100)preferred orientation by X-ray diffraction(XRD)analysis.The antiferroelectricity of the films is confirmed by the double hysteresis behaviors of polarization and double-bufferfly response of dielectric constant under the applied electrical field.Antiferroelectric properties and dielectric constant are improved while the polarization characteristic values are reduced with the increase of precursor solution concentration.The films at higher precursor solution concentration exhibit excellent dielectric properties.
基金National Natural Science Foundation of China (52102267, 22209079 and 52162028)。
文摘Colloids are a vital component of perovskite precursor solutions(PPSs),significantly influencing the quality of perovskite film formation.Despite their importance,a comprehensive understanding of these colloids remains elusive.In this work,we explored the colloidal compositions of two distinct PPS types:the monomer-mixing dissolution(MMD)and the pre-synthesized perovskite single crystal redissolution(SCR).We have uncovered a new dissolution chemical equilibrium mechanism where the transition from mixed monomers to the 3C cubic phase(α-phase)involves a reversible transformation.Our findings indicate that although colloidal size significantly affects the nucleation during perovskite crystallization,the composition of the colloids plays a more crucial role.The MMD method yields poly Pb-I·solvent clusters while the colloids derived from the SCR approach produce hexagonal lead-halide-based perovskite phase clusters.These divergent colloidal compositions lead to markedly different impacts on the perovskite film formation process.Notably,hexagonal-phase colloids act as favorable nucleation sites,promoting the generation of theα-phase perovskite films with larger grains,more homogeneous phases,and fewer defects.This work demonstrates the importance of tailoring colloidal compositions and provides theoretical insights into the beneficial effects of redissolving perovskite in forms such as powder,microcrystals,and single crystals.
基金the support from the National Natural Science Foundation of China(NSFC)(U20A20128,52163019 and 51963016)the support from the Natural Science Foundation of Jiangxi Province(20224ACB214006 and 20232ACB204005)。
文摘At present,the development of perovskite solar cells(PSCs)is progressing rapidly,but the issue of poor stability remains a significant challenge.Achieving a stable precursor solution is crucial for the large-scale production of high-quality PSC films.In this study,we successfully developed a strategy to improve the long-term stability of the precursor solution and improve device performance by employing 1-n-butyl-3-methylimidazolium di-n-butyl phosphate(BMIMBP)as an anti-aging additive.The BP−component inhibits the reactivity of I−and formamidinium ion through multiple chemical bonds,thereby stabilizing the precursor solution.In addition,the BMIM+component,which contains an amino group,can form two-dimensional perovskite internally,further enhancing the device stability.This strategy provides valuable guidance for achieving long-term stability in solar cells.
基金supported by the National Key Basic Research Program of China(973 Program,2012CB224802)the SINOPEC project(No.114013)
文摘The molecular structures of metal precursors in the impregnating solution were designed so as to prepare efficient Ni Mo/Al_2O_3 hydrodesulfurization(HDS) catalysts. At first, five typical impregnating solutions were designed; the existing metal precursors, such as [Mo4(citrate)2O11]^(4-)-like, [P2Mo18O62]^(6-)-like and [P2Mo5O23]^(6-)-like species in the solutions were confirmed by laser Raman spectroscopy(LRS). The UV-Vis spectra results indicated that the solutions containing both phosphoric acid and citric acid could change the existing form of nickel species. Five corresponding Ni Mo/Al_2O_3 catalysts were prepared by the incipient wetness impregnation method. The LRS analysis results of dried catalysts showed that the above metal precursors could be partly retained on alumina support after impregnation and drying, although the interface reaction between different metal precursors and alumina support unavoidably took place. Then the catalysts were sulfided and characterized by N2 physisorption, TEM and XPS analyses. The results showed that different metal precursors in impregnating solution could mainly result in the difference in both the morphology of(Ni)Mo S2 slabs and the promoting effect of Ni species. The catalyst prepared mainly with [P2Mo5O23]^(6-)-like species used as precursors exhibited worse dispersion of(Ni)Mo S2 slabs and lower ratio of Ni–Mo–S active phases than the one with [Mo4(citrate)2O11]^(4-)-like species. Promisingly, the catalyst prepared with co-existing [Mo4(citrate)2O11]^(4-)-like, [P2Mo18O62]^(6-)-like and [P2Mo5O23]^(6-)-like species showed better hydrodesulfurization activity for 4,6-DMDBT thanks to its more well-dispersed Ni–Mo–S active phases.
基金supported by Natural Science and Engineering Research Council Canada Discovery Grants Program(No.RGPIN-2015-06377(TWC))Natural Science and Engineering Research Council Canada Green Surface Engineering for Advanced Manufacturing(Green-SEAM)Strategic Network。
文摘The basis of the hydrophobicity of lanthanide rare earth oxides(REOs)has been the subject of considerable debate.To explore this question,the wetting behaviors and surface compositions of hierarchicallystructured Yb_(2)o_(3)(one of the REOs)coatings and non-REO Al_(2)o_(3)coatings deposited via solution precursor plasma spray process were investigated in this work.The Yb_(2)o_(3)coatings were subjected to a number of post-deposition treatments including vacuum(1-15 Pa)treatment,Ar-plasma treatment,heat treatment(400℃),long-time air exposure and ultra-high vacuum(1×10^(-7)Pa)treatment.Subsequent characterization showed that different post-deposition treatments resulted in different wetting behavior for the Yb_(2)o_(3)coatings which correlated with the content of hydrocarbon on the surface.Yb_(2)o_(3)coatings exhibited reversible transitions between superhydrophobicity after vacuum treatment and superhydrophilicity after Ar-plasma or heat treatment,linked to hydrocarbon adsorption onto and desorption from the surface.Yb_(2)o_(3)coatings after long-time air exposure and ultra-high vacuum treatment both remained hydrophilic and showed a smaller hydrocarbon content than coatings after vacuum treatment.Al_(2)o_(3)coatings with hierarchical surface structures similar to the Yb_(2)o_(3)coatings showed an increase in WCA to only-170 after the same vacuum treatment,indicating the REO has a much higher affinity for hydrocarbon adsorption than Al_(2)o_(3),and that the content of hydrocarbon adsorbed on the surface of the REO determined the wetting behavior.
文摘Organic-inorganic lead halide perovskites represent a group of materials with diverse structures and promising optical/optoelectronic properties.The performance of perovskite based solar cells relies tremendously on the structure/properties of the absorber.The physicochemical properties of the perovskite active layer depend on the substrate,preparation methods,environments and the starting materials.In this study,we investigated the effects of starting materials in the precursor solution on the physicochemical properties of the resulting one-step spin coated MA_(0.8)FA_(0.2)PbI_(3-y)Br_(y) film and the photovoltaic performance of the corresponding inverted(p-i-n)perovskite solar cells.Two precursor solutions containing exactly the same atom stoichiometry were prepared from two different groups of starting materials(Group A:CH_(3)NH_(3)I,CH(NH_(2))_(2)I,CH_(3)NH_(3)Br,and PbI_(2);Group B:CH_(3)NH_(3)I,CH(NH_(2))_(2)I,PbI_(2) and PbBr_(2)).The MA_(0.8)FA_(0.2)PbI_(3-y)Br_(y) films(A1 and A2)prepared from the A precursor solution had better photovoltaic performances compared to those(B1 and B2)obtained from the B precursor solution for the same y values.The stoichiometry of the film to achieve the best photovoltaic performance(the corresponding cell has the highest efficiency)is not the same for the A-group(prepared from the A precursor solution)and B-group films(prepared from the B precursor solution).The photovoltaic performance of the perovskite film is directly correlated to the crystallinity,morphology and defect sites of the film as evidenced by GIXRD,scanning electron microscopy(SEM)and transient photoluminescence(TRPL)data.The morphology of the mixed-halide perovskite films depends on the homogeneity of the halide stoichiometries.The A-group films with more possible halide stoichiometries have better crystallinity and continuity compared to those of the B-group films,probably due to the difference in the crystallization rates for the two group perovskite films.Therefore,for preparing mixed-halide perovskites with the same average halide stoichiometry,starting materials that can produce perovskite films with more halide stoichiometries are a better choice.
基金funded by the National Natural Science Foundation of China(51902148,61704099,51801088 and 51802024)the Fundamental Research Funds for the Central Universities(lzujbky2020-61,lzujbky-2019-88 and lzujbky-2020-kb06)the Special Funding for Open and Shared Large-Scale Instruments and Equipments of Lanzhou University(LZU-GXJJ-2019C023 and LZU-GXJJ-2019C019)。
文摘Recently,perovskite solar cells(PSCs) have flourished,and their power conversion efficiency(PCE) has increased from the initial 3.8% to 25.2% in 2019,which is an unprecedented advance.However,usually high-efficiency and stable PSCs are small-area devices prepared by spin coating.This method is not suitable for the preparation of large-area devices in commercialization.Therefore,there is an urgent need to develop new materials and methods for the scalable fabrication of PSCs.In this review,we first describe the common small-area PSCs preparation methods,understand the nucleation and crystal growth kinetics of perovskite,and analyze the reasons that hinder the development of small-area devices to large-area devices.Next,in order to meet the challenges of PSC’s scalable fabrication,we summarize and analyze four strategies:scaling up precursor solutions,scalable deposition methods for large-area films,scaling up charge-transport layers and back electrodes,developing solar modules.Finally,challenges and prospects are proposed to help researchers prepare high-efficiency large-area PSCs.
基金financial support by the Open Project Program of the State Key Laboratory of Solid Lu-brication, Lanzhou Institute of Chemical Physics,Chinese Academy of Sciences (0804)
文摘Selective-controlled structure and shape of CeVO4 nanocrystals were successfully synthesized via a hydrothermal method from Na3VO4·12H2O and Ce（NO3）3·6H2O.The resulting products were characterized by X-ray powder diffraction （XRD）,field emission scanning electron microscopy （FESEM） and energy dispersive spectroscopy （EDS）.The influence of hydrothermal temperature,precursor solution concentration on the crystal and morphology of products were further studied.The results showed that the as-synthesized products exhibited pure single-crystal CeVO4 nanoparticles with tetragonal structure.The hydrothermal temperature and precursor solution concentration had important effects on the formation of CeVO4 nanoparticles.Furthermore,the growth mechanism of CeVO4 nanoparticles was explained with Ostwald ripening mechanism.
基金financially supported by the National Key R&D Program of China(No.2021YFB3503102)Zhejiang Provincial Key R&D Program(No.2021C01191)+2 种基金Science and Technology Innovation 2025 Major Project of Ningbo(No.2020Z037)Ningbo Key R&D Program(No.20222ZDYF020027)Ningbo Natural Science Foundation(No.2021J216)。
文摘Cu-rich cell boundary phase is difficult to precipitate evenly,resulting in a generally poor demagnetization curve squareness for Fe-rich Sm_(2)Co_(17)-type magnet,which is a key factor limiting the further improvement of magnetic energy product.In this study,we report that nanoscale strip-like ordered micro-domains distributed in1:7H disordered matrix phase of the solid solution precursor is a new factor significantly affecting the precipitation and distribution of the cell boundary phase.Long strip-like and continuous micro-twin structure with twin boundaries neatly perpendicular to the C-axis is observed after sintering treatment.After solution treatment,sequential and long strip-like micro-twins gradually transform into disordered state along the basal plane,forming narrow disordered 1:7H(TbCu_(7)-type structure)phase between the separated strip-like ordered micro-domains.This disordering transformation takes place via broken down of the long strip-like ordered micro-domains,which is accomplished by narrowing along the width direction followed by reduction of the length.Furthermore,a new model revealing the effect of the ordered micro-domains on the formation of the cell boundary phase is proposed.Antiphase boundaries enriched in Cu have already existed in the precursor with long strip-like ordered micro-domains.Therefore,the Cu-rich cell boundary phase acting as strong pinning centers cannot be precipitated homogeneously and distributed continuously after aging,resulting in a poor demagnetization curve squareness of Sm_(2)Co_(17)-type magnet.Our results indicate that significant broken down of the nanoscale ordered micro-domains in solution precursor is the key factor improving the distribution of cell boundary phase in Sm_(2)Co_(17)-type magnets.
基金National Basic Research Program of China(2016YFA0202400,2015CB932200)National Natural Science Foundation of China(21403247)External Cooperation Program of BIC,Chinese Academy of Sciences(GJHZ1607)。
文摘High quality perovskite films were fabricated from different precursor solutions containing a certain proportion of different hydrogen halides.An anti-solvent,toluene,was used here to isolate an intermediate from the perovskite precursor solution to reveal the impact of the hydrogen halides on the crystallization of perovskite films.From the Fourier transform infrared spectra we found that the stretch vibration of C=O for pure N,N-dimethylformamide(DMF)appeared at 1663 cm^(-1),which was shifted to a smaller wavenumber while reacting DMF with CH_(3)NH_(3)I(MAI)+PbI_(2)and MAI+PbI_(2)+HX(X=Cl,Br,I).Moreover,the appearance of X-ray diffraction(XRD)peaks at low angles(near 8 degrees)as well as some small angle shift showed that the MAI-PbI_(2)-DMF-xHX(X=Cl,Br,I)intermediate was formed,which benefits perovskite crystallization because the formation of the intermediate will avoid a rapid reaction between MAI and PbI_(2).What's more,the solubility of the precursor can be improved by adding hydrogen halides.By adding a certain amount of hydrogen halide into the one-step perovskite precursor solution we can obtain pin-hole free and almost no defect films.Transient absorption(TA)was carried out to investigate the charge recombination in intrinsic perovskite films and perovskite devices,giving some reasonable interpretations.
基金supported by the National Natural Science Foundation of China(22109166 and 22279083)the Chinese Academy of Sciences.
文摘Perovskite solar cells(PSCs)are promising next-generation photovoltaics due to their unique optoelectronic properties and rapid rise in power conversion efficiency.However,the instability of perovskite materials and devices is a serious obstacle hindering technology commercialization.The quality of perovskite films,which is an important prerequisite for long-term stable PSCs,is determined by the quality of the precursor solution and the post-deposition treatment performed after perovskite formation.Herein,we review the origin of instability of solution-processed PSCs from the perspectives of the precursor solutions and the perovskite films.In addition,we summarize the recent strategies for improving the stability of the perovskite films.Finally,we pinpoint possible approaches to further advance their long-term stability.
基金the National Natural Science Foundation of China(U1401244,51773045,21572041,21772030,51503050,21704021 and 51572254)the National Key Research and Development Program of China(2017YFA0206600 and 2017YFA0402800)for financial support。
文摘A perovskite material CsAg_(2)Sb_(2)I_(9)was developed by dissolving CsI,AgI and SbI_(3)in DMF(molar ratio 1:2:2).CsAg_(2)Sb_(2)I_(9)solar cells gave a power conversion efficiency of 0.99%and a fill factor of 67.1%.The morphology of a CsAg_(2)Sb_(2)I_(9)film was affected significantly by the CsI content in the precursor solution.
基金support from the National Key R&D Program of China(2017YFA0207302)the National Natural Science Foundation of China(21890752,21731005,21721001 and 21805232)the Fundamental Research Funds for Central Universities(20720180061 and 20720180026).
文摘We demonstrate in this work that N-methyl-2-pyrrolidone(NMP)is a superior alternative to dimethyl sulfoxide(DMSO)as an additive in a precursor solution for the fabrication of high-quality perovskite films for solar cells.While the DMSO-assisted method always requires the films to be prepared with a low and restricted PdI_(2):DMSO ratio,NMP provides a much wider window of the PbI_(2)/NMP ratio for the preparation of high-quality perovskite films.The systematic studies on the structures of intermediates obtained with different PbI_(2)/NMP ratios reveal that only one kind of intermediate forms regardless of the Pb^(2+)/NMP ratio between 1 and 4,which is totally different from the situation of a PbI_(2)/DMSO system.But all the perovskite solar cell devices fabricated with different Pb^(2+)/NMP ratios show similar performances to their counterpart fabricated with 1:1 Pb^(2+)/DMSO.Besides the MAPbI_(3)(MA=CH_(3)NH_(3)+)system,NMP is shown to be an excellent coordinative additive for the fabrication of high-quality triple-cation(Cs^(+)/formamidinium/MA)perovskite films.
基金supported by the National Natural Science Foundation of China(No.51572020 and 51772023).
文摘The poisonous metal lead(Pb)is one of the key limiting factors for the large-scale industrial application ofperovskite solar cells(PSCs).Here,we replaced some of the lead iodide(PbI_(2))with strontium iodide(SrI_(2))in the precursor solution to prepare Pb-less perovskite films and fabricate mesoscopic solar cells via theantisolvent-assisted single step method and the two-step spin-coating method.The effect of Sr substitutionon the film formation and photovoltaic properties of perovskites was illuminated by scanning electronmicroscopy(SEM),X-ray diffraction(XRD)and time-resolved photoluminescence(TRPL)analyses.The results show that,in the antisolvent-assisted single step method,Sr substitution has an impact on theformation of the intermediate phase,resulting in a lower coverage and an increased defect density ofperovskite films.When the Sr content rises from 0 to 5 mol%,the device’s power conversion efficiency(PCE)decreases from 15.22%to 6.37%.In the two-step spin-coating method,a moderate amount of SrI_(2)can change the chemical composition of the PbI_(2)precursor,resulting in less PbI_(2)and a decreased defectdensity in perovskite films.When the Sr content is 10 mol%in the PbI_(2)solution,the solar cell exhibits aconsiderable PCE of 15.52%under AM 1.5G solar illumination.
基金This work was supported by the National Basic Research Program of China （No. 2014CB643503）, the National Natural Science Foundation of China （Nos. 91233114, 51373151 Zhejiang Province Natural LR15E030001）. and 51261130582） and Science Foundation （No.
文摘We systematically investigated the development of film morphology and crystallinity of methyl-ammonium bismuth （Ⅲ） iodide （MA3Bi2I9） through one- step spin-coating on TiO2-deposited indium tin oxide （ITO）/glass. The precursor solution concentration and substrate structure have been demonstrated to be critically important in the active-layer evolution of the MA3Bi2I9-based solar cell. This work successfully improved the cell efficiency to 0.42% （average： 0.38%） with the mesoscopic architecture of ITO/compact-TiOdmesoscopic-TiO2 （meso-TiO2）/ MA3Bi2I9/2,2＇,7,7＇-tetrakis（N,N-di-4-methoxyphenylamino）-9,9＇spiro-bifluorene （spiro-MeOTAD）/MoO3/Ag under a precursor concentration of 0.45 M, which provided the probability of further improving the efficiency of the BiB＋-based lead-free organic-inorganic hybrid solar cells.
基金supported by the Natural Science Foundation of Jiangsu Higher Education Institution of China(Grant No.20KJB430003)the open project of Key Laboratory of Green Fabrication and Surface Technology of Advanced Metal Materials(Grant No.GFST2021KF01)Humboldt Fellowship for Postdoctoral Researcher(Dr.Zexin YU).
文摘With the development of society,human beings are facing environmental problems and an energy crisis worldwide.In this context,photocatalysis and electrocatalysis represent promising technologies to help solving these issues.Up to now,most of the catalysts intended for these usages are prepared via time-consuming wet-chemical approaches,e.g.hydrothermal or sol–gel methods.Moreover,these techniques produce powdery catalysts which need not only a post-filtration step,but also a shaping by a binder for their final applications,which makes the manufacturing cumbersome.Thermal spraying is currently a well-established deposition technique that is capable of elaborating a wide series of functional coatings based on all classes of materials(metals,polymers,ceramics)and featuring tunable compositions as well as micro-and nanostructures.In particular,thermal involving liquid feedstock,and more specifically precursor solutions or suspensions,have allowed generating a wide range of coating thicknesses,from the tenmicron to the submicron/nano scale,increasing thereby the possibilities for enhancing catalytic performances.The present review sets out marking researches relating to the preparation and testing of(i)some photocatalytic coatings intended for the degradation of aqueous organic pollutants and(ii)electrocatalytic coatings investigated as potential energy storage devices.This paper will not only deal with the preparation of catalysts via different thermal spray processes,but also will cover the adjustment of phase compositions and microstructures that are rendered possible when using liquid feedstock thermal spray techniques with the prospect of optimizing the catalytic performances.
