Crystallization management of CsPbI_(2)Br perovskites by PbAc_(2)-incorporated twice spin-coating process for efficient and stable CsPbI_(2)Br perovskite solar cells

CsPbI_(2)Br perovskite solar cell has been extensively studied due to its exceptional thermal stability and relatively stable perovskite phase structure.However,the presence of bromine leads to a rapid crystallization rate of CsPbI_(2)Br films,resulting in small grain size and high defect density.Additionally,CsPbI_(2)Br demonstrates poor light absorption due to its wide bandgap.Therefore,it is crucial to control the crystallization rate and increase the film thickness to reduce defect density,enhance light absorption,and improve photovoltaic performance.In this study,we utilized a PbAc_(2)-incorporated twice spincoating(PTS) process to address these issues.Initially,PbAc_(2) was added to the CsPbI_(2)Br precursor solution to form a CsPbI_(2)Br film,which was then coated with the CsPbI_(2)Br precursor solution to produce the PTS film,Ac^(-)can delay the perovskite crystallization,leading to the formation of thicker and denser CsPbI_(2)Br films.Moreover,lone-pair electrons of the oxygen atom provided by Ac^(-)formed coordination bonds with under-coordinated Pb~(2+) ions to fill halogen ion vacancies,thereby reducing the defect density.Ultimately,the PTS CsPbI_(2)Br device achieved a peak power conversion efficiency(PCE) of 16.19% and maintained 96.7% of its initial PCE over 1500 h at room temperature under 25% relative humidity without any encapsulation.

C_(12)-s-C_(12)·2Br和TritonX-100混合水溶液的胶团生成

季铵盐二聚表面活性剂 C1 2 -s-C1 2 · 2 Br(s=2 ,3 ,4,6)和非离子表面活性剂 TX-1 0 0在水溶液中生成混合胶团。其临界胶团总浓度 cmc T值介于二元复配体系中各组分的临界胶团浓度 cmc01 和 cmc02 之间。当添加少量非离子型表面活性剂 (在水溶液中的摩尔分数α2 =0 .1 )时 ,混合胶团中 TX-1 0 0的摩尔分数≥ 0 .4;随着溶液中非离子型表面活性剂含量的增大 ,混合胶团中逐渐以 TX-1 0 0成分为主。

Experimental studies on gas-phase mercury oxidation removal and denitration of coal combustion with NH_4 Br addition

In order to remove gas-phase mercury and NOx from flue gas, experimental studies on flue gas mercury oxidation removal and denitration of Guizhou anthracite combustion with NH4Br addition were carried out. The influence of NH4Br addition on the ignition temperature and combustion characteristics was studied using a thermogravimetric analyzer. The effects of the NHaBr addition amount on gas-phase mercury oxidation and removal were investigated in a bench scale of 6 kW fluidized bed combustor （FBC）. Mercury concentrations in flue gas were determined by the Ontario hydro method （OHM） and the mercury mass balance was obtained. Results show that the NH4Br addition has little influence on the ignition temperature of Guizhou anthracite. With the mercury mass balance of 95.47%, the proportion of particulate mercury Hg^p, gaseous mercury Hg^0 and Hg^2＋ are 75.28%, 11.60% and 13. 12%, respectively, as raw coal combustion. The high particulate mercury Hg^p in flue gas is caused by the high unburned carbon content in fly ash. When the NH4Br addition amount increases from 0 to 0. 3%, the concentration of gaseous Hg^0 and Hg^2＋ in flue gas decreases continuously, leading to the Hg^p increase accordingly. The oxidation rate of Hg^0 is positively correlated to the Br addition amount. It demonstrates that coal combustion with NH4Br addition can promote Hg^0 oxidation and removal. NOx concentration in flue gas exhibits a descending trend with the NHaBr addition and the removal rate reaches 17.31% with the addition amount of 0.3%. Adding NH4Br to coal also plays a synergistic role in denitration.

硫化温度及硫化程度对NR/BR共混胎面胶性能的影响

研究了硫化温度及硫化程度对天然橡胶(NR)/顺丁橡胶(BR)共混胎面胶性能的影响。结果表明,当硫化程度在90%~105%且硫化温度为145℃时,硫化程度对硫化胶60℃下tanδ及耐磨性等的影响较小;当硫化温度为155℃时,硫化程度对硫化胶60℃下tanδ及耐磨性等的影响较大;145℃硫化胶苛刻条件下耐磨性较好,155℃硫化胶一般条件下耐磨性较好;硫化温度为155℃时,硫化程度可控制在95%~100%,其硫化胶60℃下tanδ达到145℃硫化胶同样效果。

Heterotrimeric G protein α subunit is involved in rice brassinosteroid response

Heterotrimeric G proteins are known to function as messengers in numerous signal transduction pathways.The nullmutation of RGA(rice heterotrimeric G protein α subunit),which encodes the α subunit of heterotrimeric G proteinin rice,causes severe dwarfism and reduced responsiveness to gibberellic acid in rice.However,less is known aboutheterotrimeric G protein in brassinosteroid(BR)signaling,one of the well-understood phytohormone pathways.In thepresent study,we used root elongation inhibition assay,lamina inclination assay and coleoptile elongation analysis todemonstrated reduced sensitivity of dl mutant plants(caused by the null mutation of RGA)to 24-epibrassinolide(24-epiBL),which belongs to brassinosteroids and plays a wide variety of roles in plant growth and development.Moreover,RGA transcript level was decreased in 24-epiBL-treated seedlings in a dose-dependent manner.Our results show thatRGA is involved in rice brassinosteroid response,which may be beneficial to elucidate the molecular mechanisms of Gprotein signaling and provide a novel perspective to understand BR signaling in higher plants.

Determination of contents of eight alkaloids in fruits of Macleaya cordata (Willd) R. Br. from different habitats and antioxidant activities of extracts

A reliable ultrasound-assisted extraction （UAE） method combined with HPLC-UV for quantification of eight active alkaloids in fruits of Macleaya cordata （Willd） R. Br. was developed. The optimization conditions of UAE were obtained by using Box-Behnken design of response surface methodology. Chromatography was carried out using a Kromasil C18 column by gradient elution with 0.1% phosphoric acid aqueous solution for HPLC-UV. All calibration curves showed good linear correlation coefficients （R^2〉0.999 6） and recoveries （from 97.3% to 104.9%） were acceptable. 1,1-diphenyl-2-picrylhydrazyl （DPPH） method was employed to test the antioxidant activity of the extract from the samples. The proposed method was successfully applied to quantifying eight components in nine samples of M.cordata, and significant variations of alkaloid contents and antioxidant aetivity of the samples from different habitats were demonstrated. It presents a powerful proof for the selection of the best sources to extract eight kinds of alkaloids.

A high-surface-area silicoaluminophosphate material rich in Brnsted acid sites as a matrix in catalytic cracking

A transparent gel-like mesoporous silicoaluminophosphate material （SAP） with molar ratio of Si/Al = 20 was synthesized by hydrothermal method. The physicochemical features of SAP were characterized by XRD, XRF, BET, SEM and FT-IR spectroscopy of pyridine adsorption techniques. The results indicated that incorporation of phosphorus （P） into aluminasilica system altered the basic textural characteristics of aluminasilica. Especially after hydrothermal treatment, the material with large special surface area （up to 492 m2/g） exhibited a good performance on hydrothermal stability. Moreover, the phosphorus modifier can not only increase the amount of Br／＂{o}nsted acidic sites （up to 48.44 μmol/g） and the percentage of weak acidic sites in total acidic sites, but also regulate the acid type, such as the ratio of B/L （Lewis acid/Br？nsted acid） increased to 1.15. The performances of samples as matrices for the catalytic cracking of heavy VGO were investigated. At 520 ℃, the catalysts showed much higher gasoline and diesel oil yields achieving to 45.59 wt% and 19.20 wt%, respectively, and lower coke selectivity （2.86%） than conventional FCC matrices, such as kaolin and amorphous silica-alumina.

Solubility and thermodynamics of lamotrigine in ternary mixtures of ionic liquids([OMIm][Br]+[HMIm][Br]+water)at different temperatures

Experimental mole fraction solubility of lamotrigine(LTG)in ternary aqueous mixtures of two ionic liquids(ILs),1-hexyl and 1-octyl-3-methylimidazolium bromide,[HMIm][Br]and[OMIm][Br]were reported at several temperatures T=(293.15 to 313.15)K.The van’t Hoff and(Jouyban-Acree-van’t Hoff,E-Jouyban-Acree-van’t Hoff,e-NRTL,UNIQUAC and Wilson)models were used to correlate the solubility data.The comparison of the models with temperature and solvent composition dependencies shows that the Wilson model has the minimum ARD which are relatively close to those obtained from Jouyban-Acree-van’t Hoff and E-Jouyban-Acree-van’t Hoff models and maximum ARD belonged to the UNIQUAC model.The order of ARDs for these models is:Wilson b Jouyban-Acree-van’t Hoff,E-Jouyban-Acree-van’t Hoff b e-NRTL b UNIQUAC.Moreover,the apparent thermodynamic functions,Gibbs free energy,enthalpy and entropy of dissolution and mixing were calculated based on the van’t Hoff and Gibbs free energy equations.The strong LTG-ILs interactions and enthalpic contribution of the dissolution process resulted from the calculated thermodynamic functions.

Facile synthesis of Bi_(12)O_(17)Br_2 and Bi_4O_5Br_2 nanosheets:In situ DRIFTS investigation of photocatalytic NO oxidation conversion pathway

Bi12O17Br2and Bi4O5Br2visible‐light driven photocatalysts,were respectively fabricated by hydrothermal and room‐temperature deposition methods with the use of BiBr3and NaOH as precursors.Both Bi12O17Br2and Bi4O5Br2were composed of irregular nanosheets.The Bi4O5Br2nanosheets exhibited high and stable visible‐light photocatalytic efficiency for ppb‐level NO removal.The performance of Bi4O5Br2was markedly higher than that of the Bi12O17Br2nanosheets.The hydroxyl radical(?OH)was determined to be the main reactive oxygen species for the photo‐degradation processes of both Bi12O17Br2and Bi4O5Br2.However,in situ diffuse reflectance infrared Fourier transform spectroscopy analysis revealed that Bi12O17Br2and Bi4O5Br2featured different conversion pathways for visible light driven photocatalytic NO oxidation.The excellent photocatalytic activity of Bi4O5Br2resulted from a high surface area and large pore volumes,which facilitated the transport of reactants and intermediate products,and provided more active sites for photochemical reaction.Furthermore,the Bi4O5Br2nanosheets produced more?OH and presented stronger valence band holeoxidation.In addition,the oxygen atoms of NO could insert into oxygen‐vacancies of Bi4O5Br2,whichprovided more active sites for the reaction.This work gives insight into the photocatalytic pollutant‐degradation mechanism of bismuth oxyhalide.

The alcoholysis of acetonitrile prompted by Brфnsted acidic ionic liquid [HSO_3-pmim]HSO_4

BrФnsted acidic ionic liquids based on imidazolium cation were employed as a series of environmentally benign catalysts and mediums in the alcoholysis of acetonitrile to synthesize ester. The results showed that BrФnsted acidic ionic liquid [HSO3- pmim]HSO4 was an efficient catalyst and medium for the alcoholysis of acetonitrile which could be recycled easily without obvious decline in catalytic activity, the highest yield could reach 85%.

Enhanced Photocatalytic Activity of Nanoparticle-Aggregated Ag–AgX(X=Cl, Br)@TiO_2 Microspheres Under Visible Light

Ag–AgX(X = Cl, Br)@TiO_2 nanoparticle-aggregated spheres with different mass ratio of R = TiO2/Ag(X) from 35:1 to 5:1 were synthesized by a facile sol–gel technique with post-photoreduction. The photocatalytic activities of both Ag–Ag Cl@TiO_2 and Ag–Ag Br@TiO_2 under visible light are effectively improved by ~3 times relative to TiO_2 NPAS under the simulated sunlight for the decomposition of methyl orange(MO). Ag–AgBr@TiO_2 showed 30% improvement and less stable in photocatalytic activity than that of AgCl@TiO_2. The role of Ag and Ag X nanoparticles on the surface of Ag–Ag X(X = Cl,Br)@TiO_2 was discussed. Ag on these samples not onlycan efficiently harvest visible light especially for Ag Cl, but also efficiently separate excited electrons and holes via the fast electron transfer from Ag X(X = Cl, Br) to metal Ag nanoparticles and then to TiO_2-aggregated spheres on the surface of heterostructure. On the basis of their efficient and stable photocatalytic activities under visible-light irradiation, these photocatalysts could be widely used for degradation of organic pollutants in aqueous solution.

Effect of calcination temperature on microstructure and photocatalytic activity of BiOX(X=Cl,Br)

A series of BiOX(X=Cl,Br) were prepared by simple hydrolysis and then calcined at various temperatures and they were characterized by XRD,Raman,SEM,DSC-TGA,BET and UV-Vis.The photocatalytic activity was evaluated by photocatalytic degradation of methyl orange(MO) solution under simulated solar light irradiation.The results show that the phase structure,crystallite size,morphology,specific surface area,porous structure,and the absorption band-edges are related to the calcination temperature.For BiOBr,it has completely transformed to Bi24O31Br10 at 600℃ and begins to transform to Bi2 O3 at 800℃.As for BiOCl,it begins to transform to Bi24O31Cl10 at 600℃ and completely transforms to Bi24O31Cl10 at 800℃.Finally,the photocatalytic activity of BiOCl decreases with the temperature increasing owing to decrease of the specific surface areas and pore size,while the photocatalytic activity of BiOBr increases in the first stage and then decreases,which is related to good crystallization and three-dimensional structure.

Effective Surface Treatment for High‑Performance Inverted CsPbI2Br Perovskite Solar Cells with Efficiency of 15.92%

Developing high-efficiency and stable inverted CsPbI2Br perovskite solar cells is vitally urgent for their unique advantages of removing adverse dopants and compatible process with tandem cells in comparison with the regular.However,relatively low opening circuit voltage(Voc)and limited moisture stability have lagged their progress far from the regular.Here,we propose an effective surface treatment strategy with high-temperature FABr treatment to address these issues.The induced ions exchange can not only adjust energy level,but also gift effective passivation.Meanwhile,the gradient distribution of FA+can accelerate the carriers transport to further suppress bulk recombination.Besides,the Br-rich surface and FA+substitution can isolate moisture erosions.As a result,the optimized devices show champion efficiency of 15.92%with Voc of 1.223 V.In addition,the tolerance of humidity and operation get significant promotion:maintaining 91.7%efficiency after aged at RH 20%ambient condition for 1300 h and 81.8%via maximum power point tracking at 45°C for 500 h in N2.Furthermore,the unpackaged devices realize the rare reported air operational stability and,respectively,remain almost efficiency(98.9%)after operated under RH 35%for 600 min and 91.2%under RH 50%for 300 min.

Thermodynamic Properties for Polybrominated Dibenzothiophenes by Density Functional Theory

The thermodynamic properties of 135 polybrominated dibenzothiophenes （PBDTs） in the gaseous state at 298.15 K and 1.013×10^5 Pa, are calculated using the density functional theory （the B3LYP/6-311G^＊＊） with Gaussian 03. Based on these data, the isodesmic reacflons are designed to calculate the standard enthalpy of formation （△fH^θ） and the standard Gibbs energy of formation （△fG^θ） of PBDTs. The relations of these thermodynamic parameters with the number and positionof bromine subsfituents （NPBS） are discussed, and it is found that there exist good correlations between othermody namic parameters （including heat capacity at constant volume, entropy, enthaipy, free energy, △fH^θ, △fG^θ） and NPBS. Thoe relative stability order of PBDT congeners is proposed theoretically based on the relative magnitude of their △fG^θ. In addition, the values of molar heat capacities at constant pressure （Cp,m） for PBDT c ongelaers are calculated.

[Bmim]Br_3 as a New Reagent for Regioselective Mono-bromination of Activated Aromatics under Solvent-free Conditions

Reaction of activated aromatics containing phenobs, naphthol, methoxynaphthalenes,anisole etc. with 1-butyl-3-methylimidazolium tribromide （[Bmim]Br3） under solvent-free conditions, selectively gave the corresponding monobromination products with excellent yields.

A Simple and Selective Procedure for α-Bromination of Alkanones with [Bmim]Br_3 as a Promoter under Solvent-free Conditions

Reaction of alkanones with 1-butyl-3-methylimidazolium tribromide （[Bmim]Br3） under solvent-free conditions, selectively gave the corresponding ct-bromoalkanones with excellent yields.

Studies of Thermodynamic Properties and Relative Stability of Polybrominated Xanthones by Density Functional Theory

The thermodynamic properties of xanthone（XTH） and 135 polybrominated xanthones（PBXTHs） in the standard state have been calculated at the B3LYP/6-31G＊ level using Gaussian 03 program.The isodesmic reactions were designed to calculate the standard enthalpy of formation（△fHθ） and standard free energy of formation（△fGθ） of PBXTH congeners.The relations of these thermodynamic parameters with the number and position of Br atom substitution（NPBS） were discussed,and it was found that there exist high correlation between thermodynamic parameters（entropy（Sθ）,△fHθ and △fGθ） and NPBS.According to the relative magnitude of their △fGθ,the relative stability order of PBXTH congeners was theoretically proposed.The relative rate constants of formation reactions of PBXTH congeners were calculated,Moreover,the values of molar heat capacity at constant pressure（Cp,m） from 200 to 1000 K for PBXTH congeners were also calculated,and the temperature dependence relation of them was obtained,suggesting very good relationships between Cp,m and temperature（T,T^1 and T^2） for almost all PBXTH congeners.

Enhanced Photocatalytic Denitrification Rhodamine Bover In2O3/Bi24O31Br10 Nanocomposites under Visible Light Irradiation

A novel In203/Bi24O31Br10 composite photocatalyst, where In2O3 nanoparticleswith the diameter of about 5-10 nm were tightly attached on the surface of Bi24O31Br10 plates, wasprepared by using hydrolysis, impregnation method and post-thermal process. Photocatalyticactivity was evaluated by the degradation of Rhodamine B under the visible light irradiation.Effects of the contents of In203 nanoparticles on the optical property and photocatalytic activity of In203/Bi24O31Br10 composite were also investigated. Compared with neat In203 and Bi24O31Brlomaterials, 15In203/Bi24O31Br10 composite exhibits the best photocatalytic activity owing to theefficient separation of photogenerated electron and hole pairs, which is evidenced byphotoluminence spectra. More than 95% of Rhodamine B solution can be degraded by15In203/Bi24O31Brlo sample in 30 min.

Enhanced ambient ammonia photosynthesis by Mo-doped Bi_(5)O_(7)Br nanosheets with light-switchable oxygen vacancies

The fabrication of efficient catalysts to reduce nitrogen(N_(2))to ammonia(NH3)is a significant challenge for artificial N_(2) fixation under mild conditions.In this work,we demonstrated that the simultaneous introduction of oxygen vacancies(OVs)and Mo dopants into Bi_(5)O_(7)Br nanosheets can significantly increase the activity for photocatalytic N_(2) fixation.The 1 mol% Mo-doped Bi_(5)O_(7)Br nanosheets exhibited an optimal NH_(3) generation rate of 122.9μmol g^(-1) h^(-1) and durable stability,which is attributed to their optimized conduction band position,suitable absorption edge,large number of light-switchable OVs,and improved charge carrier separation.This work provides a promising approach to design photocatalysts with light-switchable OVs for N_(2) reduction to NH_(3) under mild conditions,highlighting the wide application scope of nanostructured BiOBr-based photocatalysts as effective N_(2) fixation systems.