Highly Efficient and Stable FAPbI_(3) Perovskite Solar Cells and Modules Based on Exposure of the(011)Facet

Perovskite crystal facets greatly impact the performance and stability of their corresponding photovoltaic devices.Compared to the(001)facet,the(011)facet yields better photoelectric properties,including higher conductivity and enhanced charge carrier mobility.Thus,achieving(011)facet-exposed films is a promising way to improve device performance.However,the growth of(011)facets is energetically unfavorable in FAPbI_(3) perovskites due to the influence of methylammonium chloride additive.Here,1-butyl-4-methylpyridinium chloride([4MBP]Cl)was used to expose(011)facets.The[4MBP]^(+)cation selectively decreases the surface energy of the(011)facet enabling the growth of the(011)plane.The[4MBP]^(+)cation causes the perovskite nuclei to rotate by 45°such that(011)crystal facets stack along the out-of-plane direction.The(011)facet has excellent charge transport properties and can achieve better-matched energy level alignment.In addition,[4MBP]Cl increases the activation energy barrier for ion migration,suppressing decomposition of the perovskite.As a result,a small-size device(0.06 cm2)and a module(29.0 cm2)based on exposure of the(011)facet achieved power conversion efficiencies of 25.24%and 21.12%,respectively.

Single-step conversion of lignin monomers to phenol: Bridging the gap between lignin and high-value chemicals

Transformation of lignin into high-value chemicals is hampered by the complexity of monomers obtained from lignin depolymerization. Here we report a strategy, composed of hy-dro-demethoxylation and de-alkylation reactions, that is able to chemically converge various lig-nin-derived phenolic monomers into phenol in a single-step. Using 2-methoxy-4-propylphenol as a model compound, Pt/C exhibited the best performance in hydro-demethoxylation reaction afford-ing 80% 4-propylphenol from 2-methoxy-4-propylphenol, while H-ZSM-5 was identified as the most suitable catalyst for de-alkylation, achieving 83% yield of phenol from 4-propylphenol. Since the two catalysts operate under compatible conditions, combining the two catalysts to simultane-ously promote both hydro-demethoxylation and de-alkylation reactions was achieved. Configura-tion of how to organize the catalysts is a critical parameter, where the physical mixture of the two was most effective, providing over 60% phenol from 2-methoxy-4-propylphenol in a single-step.

Bacterial diversity and distribution in the southeast edge of the Tengger Desert and their correlation with soil enzyme activities

The nature of microbial communities and their relation to enzyme activities in desert soils is a neglected area of investigation. To address this, the bacterial diversity and distribution and soil physico-chemical factors were investigated in the soil crust, the soil beneath the crust and rhizosphere soil at the southeast edge of the Tengger Desert, using the denaturing gradient gel electrophoresis of 16S rRNA genes amplified by the polymerase chain reaction. Phylogenedc analysis of the sequenced DGGE bands revealed a great diversity of bacteria. The Proteobacteria, consisting of the α, β, and γsubdivisions, were clearly the dominant group at all depths and in rhizosphere soil. Analysis of the enzyme activities indicated that the rhizosphere soil of Caragana korshinskii exhibited the highest protease and polyphenol oxidase activities, and in the soil crust there were increased activities of catalase, urease, dehydrogenase and sucrase. The bacterial community abundance closely correlated with soil enzyme activities in different soils. The presence of Cyanobacteria correlated with significant increases in protease, catalase and sucrase in the soil crust, and increased urease in the rhizosphere soil of Artemisia ordosica. The occurrence of Acidobacteria was associated with significant increases in urease, dehydrogenase, and sucrase in the rhizosphere soil of C. korshinski. The presence of γ-Proteobacteria correlated with a significant increase in polyphenol oxidase in the rhizosphere soil ofA. ordosica. The study indicated a close relationship between the soil bacterial community and soil enzymes, suggesting the necessity of further investigations into bacterial function in this desert ecosystem.

A simple catalyst for aqueous phase Suzuki reactions based on palladium nanoparticles immobilized on an ionic polymer

Palladium nanoparticles immobilized on a cross-linked imidazolium-containing polymer were evaluated as a catalyst for Suzuki carbon-carbon cross-coupling reactions using water as the solvent. The nanocatalysts show good catalytic activities for aryl iodides and aryl bromides and moderate activity with aryl chloride substrates. Coupling of sterically hindered substrates could also be achieved in reasonable yields. The heterogeneous catalyst is stable, can be stored without precautions to exclude air or moisture, and can be easily recycled and reused.