基于吡嗪空穴传输层的合成及在p-i-n型钙钛矿太阳能电池中的应用

钙钛矿太阳能电池由于具有高的光电转换效率,简单的溶液加工工艺,较低的成本等优势因而拥有广阔的应用前景。有机小分子空穴传输层材料在钙钛矿太阳能电池中扮演着极其重要的角色。在本工作中,我们设计和合成了基于吡嗪为分子中心核,三苯胺为分枝的X型空穴传输层材料PT-TPA。与Si-OMeTPA对比,吡嗪的引入不仅不会影响其结晶性,并且能够改善其电荷转移特性和分子中心共平面性,从而显著提升了PT-TPA的空穴迁移率。在非掺杂的情况之下,基于PT-TPA空穴传输层的p-i-n型钙钛矿太阳能电池展现出17.52%的光电转换效率,与相同条件下基于Si-OMeTPA空穴传输层的器件相比,效率提高了近15%。     

Recent Advances and Future Perspectives of Lead-Free Halide Perovskites for Photocatalytic CO2 Reduction

It is still challenging to design and develop the state-of-the-art photocatalysts toward CO₂ photoreduction. Enormous researchers have focused on the halide perovskites in the photocatalytic field for CO₂ photoreduction, due to their excellent optical and physical properties. The toxicity of lead-based halide perovskites prevents their large-scale applications in photocatalytic fields. In consequence, lead-free halide perovskites (LFHPs) without the toxicity become the promising alternatives in the photocatalytic application for CO₂ photoreduction. In recent years, the rapid advances of LFHPs have offer new chances for the photocatalytic CO₂ reduction of LFHPs. In this review, we summarize not only the structures and properties of A₂BX₆, A₂B(I)B(III)X₆, and A₃B₂X₉-type LFHPs but also their recent progresses on the photocatalytic CO₂ reduction. Furthermore, we also point out the opportunities and perspectives to research LFHPs photocatalysts for CO₂ photoreduction in the future.     

钙钛矿组分和结构设计及其发光二极管器件性能研究进展

有机-无机杂化钙钛矿发光二极管(LED)的性能在短短几年时间内飞速提升,近红外光器件的效率己达21.6％,绿光器件效率也达到20.3％,达到可以和商业化的有机发光二极管媲美的水平;即使是稍有逊色的稳定性方面也有很大进展,报道的最长器件半衰期已达到250 h.器件性能的飞速提升得益于钙钛矿本身优异的光电性质,而且通过丰富...     

钙钛矿型复合氧化物纳米粒子的合成及其对一氧化碳氧化的催化性能(英文)

以ＮａｃＯ３－ＮａＯＨ混合溶液作为沉淀剂,采用超临界干燥技术合成了钙钛矿型ＬａＢＯ３（Ｂ：ｃｏ和Ｍｎ）和Ｌａｌ　纳米粒子。所得产品的平均粒径可达约１５ｍｍ,比表面积达３０ｍ２．ｇ－１。研究结果表明,随粒径减小和比表面积增大,ＬａＢＯ３对一氧化碳氧化的催化活性明显增加;ＬａＢＯ３中镧被锶部分取代可显著提高其对一氧化碳氧化的催化活性。     

Comparison of LaFeO3, La0.8Sr0.2FeO3, and La0.8Sr0.2Fe0.9Co0.1O3 perovskite oxides as oxygen carrier for partial oxidation of methane

Comparison of LaFeO3, La0.8Sr0.2FeO3, and La0.8Sr0.2Fe0.9Co0.1O3 perovskite oxides as oxygen cartier for partial oxidation of methane in the absence of gaseous oxygen was investigated by continuous flow reaction and sequential redox reaction. Methane was oxidized to syngas with high selectivity by oxygen species of perovskite oxides in the absence of gaseous oxygen. The sequential redox reaction revealed that the structural stability and continuous oxygen supply in redox re-action decreased over La0.8Sr0.2Fe0.9Co0.1O3 oxide, while LaFeO3 and Lao.sSro.2FeO3 exhibited excellent structural stability and continuous oxygen supply.     

Comparative study of kinetic modeling for the oxidative coupling of methane by genetic and marquardt algorithms

Overall kinetic studies on the oxidative coupling of methane, OCM, have been conducted in a tubular fixed bed reactor, using perovskite titanate as the reaction catalyst. The appropriate operating conditions were found to be: temperature 750-775 ℃, total feed flow rate of 160 ml/min, CH4/O2 ratio of 2 and GHSV of 100 min-1. Under these conditions, C2 yield of 28% was achieved. Correlations of the kinetic data have been performed with lumped rate equations for C2 and COx formation as functions of temperature, O2 and CH4 partial pressures. Six models have been selected among the common lumped kinetic models. The selected models have been regressed with the experimental data which were obtained from the Catatest system by genetic algorithm in order to obtain optimized parameters. The kinetic coefficients in the overall reactions were optimized by different numerical optimization methods such as: the Levenberg-Marquardt and genetic algorithms and the results were compared with one another. It has been found that the Santamaria model is in good agreement with the experimental data. The Arrhenius parameters of this model have been obtained by linear regression. It should be noted that the Marquardt algorithm is sensitive to the first guesses and there is possibility to trap in the relative minimum.     

Hydrogen Production by Water Dissociation in Surface‐Modified BaCoxFeyZr1−x−yO3−δ Hollow‐Fiber Membrane Reactor with Improved Oxygen Permeation

A porous perovskite BaCo_xFe_yZr_0.9?x?yPd_0.1O_3?δ (BCFZ‐Pd) coating was deposited onto the outer surface of a BaCo_xFe_yZr_1?x?yO_3?δ (BCFZ) perovskite hollow‐fiber membrane. The surface morphology of the modified BCFZ fiber was characterized by scanning electron microscopy (SEM), indicating the formation of a BCFZ‐Pd porous layer on the outer surface of a dense BCFZ hollow‐fiber membrane. The oxygen permeation flux of the BCFZ membrane with a BCFZ‐Pd porous layer increased 3.5 times more than that of the blank BCFZ membrane when feeding reactive CH₄ onto the permeation side of the membrane. The blank BCFZ membrane and surface‐modified BCFZ membrane were used as reactors to shift the equilibrium of thermal water dissociation for hydrogen production because they allow the selective removal of the produced oxygen from the water dissociation system. It was found that the hydrogen production rate increased from 0.7 to 2.1 mL H₂ min^?1 cm^?2 at 950 °C after depositing a BCFZ‐Pd porous layer onto the BCFZ membrane.     

反应气中活化后的镍酸镧用于二氧化碳加氢生成甲烷

采用柠檬酸法制备了钙钛矿镍酸镧,并将其作为催化剂的前躯体用于二氧化碳甲烷化反应中。催化剂在400℃~700℃温度下反应气中进行活化处理。活化过程中生成了金属镍颗粒和碳酸氧化镧。金属镍呈高度分散状并被碳酸氧化镧包裹,这种现象有助于反应在400℃和500℃的高温下仍保持高活性和稳定性。XRD、XPS、TEM和H₂-TPD等表征测试表明,在活化过程中生成的碳酸氧化镧对反应起到了至关重要的作用。     

Low‐Temperature Facile Template Synthesis of Crystalline Inorganic Composite Hollow Spheres

This report presents a facile approach for the low‐temperature synthesis of crystalline inorganic‐oxide composite hollow spheres by employing the bulk controlled synthesis of inorganic‐oxide nanocrystals with polymer spheres as templates. The sulfonated polystyrene gel layer can adsorb the target precursor and induce inorganic nanocrystals to grow on the template in situ. The crystalline phase and morphology of the composite shell is tunable. By simply adjusting the acidity of the titania sol, crystalline titania composite hollow spheres with tunable crystalline phases of anatase, rutile, or a mixture of both were achieved. The approach is general and has been extended to synthesize the representative perovskite oxide (barium and strontium titanate) composite hollow spheres. The traditional thermal treatment for crystallite transformation is not required, thus intact shells can be guaranteed. The combination of oxide properties such as high refractive index, high dielectric constant, and catalytic ability with the cavity of the hollow spheres is promising for applications such as opacifiers, photonic crystals, high‐κ‐gate dielectrics, and photocatalysis.     

Crystal Structure and Property of Perovskite-Type Oxides Containing Ion Vacancy

Studies on the role of oxygen vacancy in structural change of nonstoichiometric perovskites and a property of oxygen-deficient perovskite-related K₂NiF₄ compounds are reviewed.The structural changes on which the authors focused are cation ordering and lattice distortion. The relationship between the distortion and oxygen vacancy was investigated by comparing the structures of Sr₂(Sr_1-xM_x)TaO_6-d (M = Ca²⁺ and Nd³⁺) solid solutions. It was found that distortion of a perovskite-type lattice decreased with an increasing amount of oxygen vacancies. In order to investigate the relationship between the cation ordering on octahedral sites and oxygen vacancy, structures of stoichiometric Sr_2-xLa_xCo_1-yTa_1+yO₆ and oxygen-deficient Sr_2-xLa_xMg_1-yTa_1+yO_6-d solid solutions were compared. The authors' work reveals that the cation ordering affects the amount of oxygen vacancies in addition to cation charge and size.