Multi-Site Intermolecular Interaction for In Situ Formation of Vertically Orientated 2D Passivation Layer in Highly Efficient Perovskite Solar Cells

Surface passivation via 2D perovskite is critical for perovskite solar cells (PSCs) to achieve remarkable performances, in which the applied spacer cations play an important role on structural templating. However, the random orientation of 2D perovskite always hinder the carrier transport. Herein, multiple nitrogen sites containing organic spacer molecule (1H-Pyrazole-1-carboxamidine hydrochloride, PAH) is introduced to form 2D passivation layer on the surface of formamidinium based (FAPbI₃) perovskite. Deriving from the interactions between PAH and PbI₂, the defects of FAPbI₃ perovskite are effectively passivated. Interestingly, due to the multiple-site interactions, the 2D nanosheets are found to grow perpendicularly to the substrate for promotion of charge transfer. Therefore, an impressive power conversion efficiency of 24.6% and outstanding long-term stability are achieved for the 2D/3D perovskite devices. The findings further provide a perspective in structure design of novel organic halide salts for the fabrication of efficient and stable PSCs.     

Unveiling the roles of alumina as a sintering aid in Li-Garnet solid electrolyte

The superiority of garnet-type solid electrolyte makes it one of most promising candidates for all-solid-state lithium batteries. Several studies show that introduction of alumina during synthesis can greatly improve the density and ionic conductivity of garnet electrolyte Li₇La₃Zr₂O₁₂ (LLZO), but the reason of poor sinterability of LLZO is still unclear. In this study, we reveal that lithium carbonate, which has a high decomposition temperature and covers on the particle surface of LLZO, is the underlying reason that handicaps the sinterability of Li-Garnet electrolyte in air. The addition of alumina promotes the decomposition of Li₂CO₃ (down to 400°C) and the concomitant product LiAlO₂, as a fast Li-ion conductor, facilitates the sintering process and bulids a fast Li-ion conducting network along the grain-boundaries, significantly increasing the ionic conductivity of Li-Garnet electrolyte. By the conventional solid state sintering, the 10 mol% Al₂O₃ modified Li_6.4La₃Zr_1.4Ta_0.6O₁₂ (LLZT-10Al₂O₃) electrolyte reaches a relative density of 96% and shows a conductivity of 0.31 mS cm⁻¹ at room temperature. The prepared LLZT-10Al₂O₃ electrolyte exhibits a good wetting property toward metallic Li electrode with an interfacial resistance of 59 Ω cm² compared to 1270 Ω cm² for LLZT/Li. This work provides a fundamental understanding and a valuable strategy for developing high performance garnet-type electrolyte for all-solid-state lithium batteries.     

Factors affecting the phase composition of 612 aluminates for Ba–W cathode

The precursor powder of 612 aluminates were synthesized by using liquid-phase co-precipitation method. The microstructure and formation mechanisms of the precursor powder were investigated through X-ray diffraction, thermal gravimetric, differential scanning calorimetry, and scanning electron microscope. The effects of the stacking states of the precursor powder, calcination temperature, and atmosphere on the phase compositions of 612 aluminates were also systematically studied. Results showed that the prepared precursor powder was a mixture of BaCO₃, BaCa(CO₃)₂, and amorphous AlOOH, which with particle size ranging from 20 to 30 nm. The stacking states of the precursor powder considerably influenced the phase composition of aluminates. The pressed precursor tablet can ensure the final phase composition of aluminates was Ba₃CaAl₂O₇. When the precursor powder was calcined in CO₂ atmosphere at 1400 °C for 2 h, the phase composition included Ba₅CaAl₄O₁₂, BaAl₂O₄, and BaCO₃. When the calcination temperature was increased, the main crystalline phase of aluminates changed from Ba₅CaAl₄O₁₂ to Ba₃CaAl₂O₇ in flowing N₂, Ar, and static air. The barium–tungsten cathode prepared by aluminates of Ba₃CaAl₂O₇ phase showed better emissivity than that of Ba₅CaAl₄O₁₂ phase. The current density of pulse emission at 1050 °C can reach 35.31 A/cm².     

A Roadmap to Low‐Cost Hydrogen with Hydroxide Exchange Membrane Electrolyzers

Hydrogen is an ideal alternative energy carrier to generate power for all of society's energy demands including grid, industrial, and transportation sectors. Among the hydrogen production methods, water electrolysis is a promising method because of its zero greenhouse gas emission and its compatibility with all types of electricity sources. Alkaline electrolyzers (AELs) and proton exchange membrane electrolyzers (PEMELs) are currently used to produce hydrogen. AELs are commercially mature and are used in a variety of industrial applications, while PEMELs are still being developed and find limited application. In comparison with AELs, PEMELs have more compact structure and can achieve higher current densities. Recently, however, an alternative technology to PEMELs, hydroxide exchange membrane electrolyzers (HEMELs), has gained considerable attention due to the possibility to use platinum group metal (PGM)‐free electrocatalysts and cheaper membranes, ionomers, and construction materials and its potential to achieve performance parity with PEMELs. Here, the state‐of‐the‐art AELs and PEMELs along with the current status of HEMELs are discussed in terms of their positive and negative aspects. Additionally discussed are electrocatalyst, membrane, and ionomer development needs for HEMELs and benchmark electrocatalysts in terms of the cost–performance tradeoff.     

Green lignin-based polyester nanofiltration membranes with ethanol and chlorine resistance

As the main water treatment material, polymeric membranes inevitably suffer from membrane fouling. In this work, novel lignin-based polyester composite nanofiltration membranes (NFM) with ethanol and chlorine resistance were fabricated via interfacial polymerization. Lignin alkali (LA), a green lignin derivative, typically treated as chemical waste in the paper industry, was employed as the aqueous monomer, trimesoyl chloride (TMC) is served as the organic monomer. The structure and separation properties of the lignin-based NFM were studied, revealing that the dense polyester separation layer may show good performance for dye removal. The rejections of the optimized LA/TMC-3 membrane with an excellent permeation flux of 13.9 kg m^?2?h^?1 for rose Bengal sodium salt, brilliant blue, congo red, rhodamine B, MgSO₄, and NaCl are 97.6%, 97.3%, 97.8%, 71.34%, 51.4%, and 31.8%, respectively. Moreover, the LA/TMC-3 membrane also shows long-term tolerance in ethanol and sodium hypochlorite solution; the rejection of LA/TMC-3 to dye only decreases 8% after 8 days when immersed in alcohol, while the normalized rejection maintains 94% after 4000 ppm-hours of continuous exposure to chlorine. This lignin-based polyester membrane may broaden the sustainable utilization sphere of lignin derivatives, at that provide a referable direction for the development of membrane materials.     

绿-黄可逆电热致变色织物的制备及其性能

石墨烯因其优异的导电性、优越的柔韧性和环境稳定性, 在可穿戴电子纺织品领域发挥了重要作用。本工作通过丝网印刷技术分别将自制的石墨烯浆料和复合热致变色油墨印在聚酯织物的正反面, 构筑了一种石墨烯基绿-黄可逆电热致变色织物。采用SEM、XRD以及FTIR等分析了织物的结构性质和变色原理, 采用红外热成像仪及全色差色度仪研究了织物的热学以及变色性能。结果表明：石墨烯电热致变色织物厚度约为250 μm, 在12 V电压下逐渐加热超过45 ℃, 焦耳热主要通过热传导至变色层, 结晶紫内酯的闭开环实现绿-黄可逆变色, 其变色响应时间约为15 s, 褪色响应时间约为27 s。石墨烯电热致变色织物经历30°~180°的弯曲角度后, 电压-电流曲线保持稳定。经200次加热/冷却循环后, 性能未发生明显衰退。本研究成功制备了颜色在绿-黄之间变化、响应迅速、循环性能良好的可逆电热致变色织物：石墨烯膜‖聚酯织物‖热致变色膜, 在军事伪装和可穿戴显示领域有一定的应用前景。     

酶膜反应器水解酪蛋白连续制备ACE抑制肽的研究

目的:将酶解与膜分离耦合,连续制备ACE抑制肽.方法:通过考察超滤膜包对原料蛋白质及酶的截留、膜通量以及膜包滤出液的ACE抑制活性,确定试验用膜包;通过优化的超滤条件,采用静态间歇式反应、半连续反应和连续反应3种不同的模式制备ACE抑制肽.结果:静态反应的得率、单位时间产量和单位活力酶对应的产量远小于半连续和连续反应,其中连续反应的得率迭43.4%,单位时间产量为6284mg,h,单位活力酶对应的产量为0.23mg/U,产物的ACE抑制率迭81.6%(1mg/mL),整个系统持续稳定反应8 h以上.结论:将醇解反应与膜分离耦合来水解牛乳酪蛋白,制备ACE抑制肽,可实现连续化生产,提高原料和酶的利用率.     

人造金刚石提纯及氧化石墨制备一体化工艺研究

综合采用磁选法、Hummers法及沉降分离法对人造金刚石一次摇床分选尾料进行提纯处理。利用X射线衍射仪、拉曼光谱仪和扫描电子显微镜进行物相组成和显微结构分析。结果表明:所得人造金刚石纯度高、回收率接近100%;同时,尾料中的石墨被转化为氧化石墨,达到了节约资源、变废为宝的目的。