Tailored Supramolecular Interactions in Host-Guest Complexation for Efficient and Stable Perovskite Solar Cells and Modules.

Host-guest complexation offers a promising approach for mitigating surface defects in perovskite solar cells (PSCs). Crown ethers are the most widely used macrocyclic hosts for complexing perovskite surfaces, yet their supramolecular interactions and functional implications require further understanding. Here we show that the dipole moment of crown ethers serves as an indicator of supramolecular interactions with both perovskites and precursor salts. A larger dipole moment, achieved through the substitution of heteroatoms, correlates with enhanced coordination with lead cations. Perovskite films incorporating aza-crown ethers as additives exhibited improved morphology, reduced defect densities, and better energy-level alignment compared to those using native crown ethers. We report power-conversion efficiencies (PCEs) exceeding 25 % for PSCs, which show enhanced long-term stability, and a record PCE of 21.5 % for host-guest complexation-based perovskite solar modules with an active area of 14.0 cm2.

Unraveling the Role of Electron-Withdrawing Molecules for Highly Efficient and Stable Perovskite Photovoltaic.

Electron-withdrawing molecules (EWMs) have exhibited remarkable efficacy in boosting the performance of perovskite solar cells (PSCs). However, the underneath mechanisms governing their positive attributes remain inadequately understood. Herein, we conducted a comprehensive study on EWMs by comparing 2,2'-(2,5-cyclohexadiene-1,4-diylidene) bismalononitrile (TCNQ) and (2,3,5,6-tetrafluoro-2,5-cyclohexadiene-1,4-diylidene) dimalononitrile (F4TCNQ) employed at the perovskite/hole transport layer (HTL) interfaces. Our findings reveal that EWMs simultaneously enhance chemical passivation, interface dipole effect, and chemically binding of the perovskite to the HTL. Notably, F4TCNQ, with its superior electron-withdrawing properties, demonstrates a more pronounced impact. Consequently, PCSs modified with F4TCNQ achieved an impressive power conversion efficiency (PCE) of 25.21%, while demonstrating excellent long-term stability. Moreover, the PCE of a larger-area perovskite module (14.0 cm2) based on F4TCNQ reached 21.41%. This work illuminates the multifaceted mechanisms of EWMs at the interfaces in PSCs, delivering pivotal insights that pave the way for the sophisticated design and strategic application of EWMs, thereby propelling the advancement of perovskite photovoltaic technology.

Molecular Dipole Engineering of Carbonyl Additives for Efficient and Stable Perovskite Solar Cells.

Carbonyl functional materials as additives are extensively applied to reduce the defects density of the perovskite film. However, there is still a lack of comprehensive understanding for the effect of carbonyl additives to improve device performance. In this work, we systematically study the effect of carbonyl additive molecules on the passivation of defects in perovskite films. After a comprehensive investigation, the results confirm the importance of molecular dipole in amplifying the passivation effect of additive molecules. The additive with strong molecular dipole possesses the advantages of enhancing the efficiency and stability of perovskite solar cells (PSCs). After optimization, the companion efficiency of PSCs is 23.20 %, and it can maintain long-term stability under harsh conditions. Additionally, a large-area solar cell module-modified DLBA was 20.18 % (14 cm2 ). This work provides an important reference for the selection and designing of efficient carbonyl additives.

Understanding the Role of Fluorine Groups in Passivating Defects for Perovskite Solar Cells.

Introducing fluorine (F) groups into a passivator plays an important role in enhancing the defect passivation effect for the perovskite film, which is usually attributed to the direct interaction of F and defect states. However, the interaction between electronegative F and electron-rich passivation groups in the same molecule, which may influence the passivation effect, is ignored. We herein report that such interactions can vary the electron cloud distribution around the passivation groups and thus changing their coordination with defect sites. By comparing two fluorinated molecules, heptafluorobutylamine (HFBM) and heptafluorobutyric acid (HFBA), we find that the F/-NH2 interaction in HFBM is stronger than the F/-COOH one in HFBA, inducing weaker passivation ability of HFBM than HFBA. Accordingly, HFBA-based perovskite solar cells (PSCs) provide an efficiency of 24.70 % with excellent long-term stability. Moreover, the efficiency of a large-area perovskite module (14.0 cm2 ) based on HFBA reaches 21.13 %. Our work offers an insight into understanding an unaware role of the F group in impacting the passivation effect for the perovskite film.

Profiles of and variations in aluminum species in PAC-MC used for the removal of blooming microalgae.

Polyaluminum chloride modified clay (PAC-MC) is a safe and efficient red tide control agent that has been studied and applied worldwide. Although it is well known that the distribution of hydrolytic aluminum species in PAC affects its flocculation, little is known about the influence of particulars aluminum species on the microalgae removal efficiency of PAC-MC; this lack of knowledge creates a bottleneck in the development of more efficient MCs based on aluminum salts. The ferron method was used in this study to quantitatively analyze the distributions of and variations in different hydrolytic aluminum species during the process of microalgae removal by PAC-MC. The results showed that Ala, which made up 5%-20% of the total aluminum, and Alp, which made up 15%-55% of the total aluminum, significantly affected microalgae removal, with Pearson's correlation coefficients of 0.83 and 0.89, respectively. Most of the aluminum in the PAC-MC sank rapidly into the sediments, but the rate and velocity of settlement were affected by the dose of modified clay. The optimal dose of PAC-MC for precipitating microalgae was determined based on its aluminum profile. These results provide guidance for the precise application of PAC-MC in the control of harmful algal blooms.

Preparation and application performance study of biomass-based carbon materials with various morphologies by a hydrothermal/soft template method.

Nitrogen-doped carbon materials with controllable morphologies were prepared via a soft template method using chitosan as the carbon and nitrogen source and F127 or ionic liquid as the template. The performance of the materials as electrodes and adsorbents for carbon dioxide removal were evaluated. Carbon spheres (CSs) with developed micropore structures were obtained without a template, whereas a tubular structure (CSF) containing mesopores with long-range order was obtained using F127. Layered carbon (CSI) containing micro-/mesopores with short- and long-range order was obtained using an ionic liquid. The samples exhibited graphite-like structure and the soft template increased the graphitization degree. Nitrogen existed mainly in the form of pyridine and pyridone groups in CSs and CSF and as pyridine, pyridone, and quaternary groups in CSI. The specific capacitances of CSs, CSF, and CSI were 144, 161, and 178 F g-1, respectively, at a current density of 1.0 A g-1 in 1 M sulfuric acid. The carbon dioxide adsorption capacities of CSs, CSF, and CSI were 142, 73, and 115 mg g-1, respectively; CSs displayed the highest value because of its developed micro- and ultramicroporous structure. Our results indicated that these carbon materials with various morphologies can be used as both electrodes and adsorbents.

Fluorinated Alcohol-Promoted Reaction of Chlorohydrocarbons with Diverse Nucleophiles for the Synthesis of Triarylmethanes and Tetraarylmethanes.

This article reports an efficient synthesis of triarylmethanes and tetraarylmethanes from chlorohydrocarbons with miscellaneous nucleophiles in fluorinated alcohols, featuring metal-free, wide substrate scope, excellent functional group tolerance, and mild reaction conditions.

Carbon composite materials with ordered mesoporous structures from straw: hydrothermal preparation and application as catalysts.

Carbon-based composite materials with tunable, ordered mesoporous structures were prepared via the hydrothermal carbonization/soft-template method, with nickel nitrate as the doping source, straw as the carbon source, and F127 as the soft template. By adjusting the additive amounts of Ni and F127, the mesoporous structure was controllable, and results were obtained that varied from an irregular stripe-like hexagonal, a regular stripe-like hexagonal, mixed hexagonal and cubic, to cubic. With a specific surface area in the range of 339-963 m2 g-1, the percentage of mesoporous structures increased from 39.6% to 58.3%. Ni doped into the carbon skeletons existed in the form of metallic Ni and nickel oxide. Increased amounts of nickel nitrate for doping as well as F127 is beneficial for the generation of metallic Ni during the preparation process. The average particle diameter of Ni decreased when the Ni-doped content was increased, and all the average particle sizes were less than 10 nm after F127 was added. The Nim/CSFn catalyst demonstrated high catalytic activity when used for the hydrogenation reaction of p-nitrophenol (PNP) to p-aminophenol (PAP). The conversion of PNP reached 98.79%, and the selectivity for PAP reached 89.6% for Ni2.0/CSF1.5, with a corresponding apparent rate constant of 1.56 × 10-3 S-1, apparent activation energy of 41.86 kJ mol-1, and with the added benefit that the catalyst could be separated and recycled by applying an external magnetic field.

Mechanism of aniline adsorption on post-crosslinked resins: pore structure and oxygen content.

A series of post-crosslinked resins were synthesized from macroporous chloromethylated styrene-divinylbenzene copolymer by controlling post-crosslinked reaction conditions. Adsorption study towards aniline showed that the three resins, ST-DVB-WH5, ST-DVB-WH6, and ST-DVB-WH7, prepared at different temperatures, and which had nearly identical static adsorption capacity, displayed great disparity in kinetic behavior. The rate constant of ST-DVB-WH7 by the pseudo-first-order model was 1.50 and 1.19 times higher than that of ST-DVB-WH5 and ST-DVB-ST-DVB-WH6. Further analysis of the diffusion model showed that the three resins exhibited different diffusion rates due to the difference in oxygen content and pore structure of each resin. The results showed that the adsorption capacity was mainly decided by the pore volume within 1.14 and 3.42 nm and the adsorption rate was mainly decided by the oxygen content of the resin. In addition, as the best synthetic resin for aniline adsorption, the equilibrium adsorption capacity of ST-DVB-WH7 was 1.57 times and 1.44 times higher than that of H-103 and NKA-II, respectively.

Effective adsorption of nitroaromatics at the low concentration by a newly synthesized hypercrosslinked resin.

In the present study, a series of hypercrosslinked resins (CH series) was prepared in systematically designed conditions for the adsorption of nitroaromatics from aqueous solution. The newly synthesized CH-10 possesses a Brunauer-Emmett-Teller (BET) surface area up to 1,329.3 m2/g which is larger than that of the widely used hypercrosslinked resin H-103 and it exhibits great advantage over H-103 when subjected to nitrobenzene at low concentrations. The adsorption capacity of CH-10 for nitrobenzene is 1.4 times as much as that of H-103 at the concentration of 100 mg/L. Kinetic study by film diffusion model and intra-particle diffusion model revealed that its distinctive mesoporous structure within pore diameters between 2 and 6 nm played significant role in the mass transfer at low concentrations, and these unique mesopores also resulted in better adsorption capacity, which was confirmed by adsorption thermodynamics study. Moreover, the CH series displayed a good affinity to a wide scope of nitroaromatics and exhibited excellent dynamic adsorption and desorption properties in fixed bed.

Cellulose nanofiber-based hybrid hydrogel electrode with superhydrophilicity enabling flexible high energy density supercapacitor and multifunctional sensors.

Flexible hybrid hydrogels (GO/AC/CNFn) with a 3D porous network structure and superhydrophilic property are synthesized by cross-linking and self-assembling graphene oxide (GO) and activated carbon (AC) with cellulose nanofiber (CNF) during microwave hydrothermal process. In this ternary composite hydrogel, CNF molecular chains bridge GO sheets to build the 3D skeleton and anchor AC particles within GO nanosheets, forming ordered architecture of GO/AC/CNFn hydrogel that simultaneously possesses high flexibility and excellent mechanical integrity. When using this hydrogel as additive-free electrode, the presence of AC provides developed porous structure and density to promote high volumetric capacitance, while the heteroatom nitrogen groups tune the surface property of the composite with increased electrical conductivity. Benefited from the optimized structure, GO/AC/CNF1 electrode delivers an ultra-high mass specific capacitance of 627 F/g and volume specific capacitance of 618 F/cm3 at 0.5 A/g in three-electrode system in 1 M H2SO4 electrolyte, which is kinetically demonstrated to be essentially originated from the capacitive contributions. The energy density reaches 32.2 Wh/kg at a power density of 150 W/kg for the fabricated flexible solid-state symmetric supercapacitor. Moreover, the obtained flexible device could sensitively response at varied physiological signals, shedding fresh lights on their potential applications in signal sensors and portable electronics.

Chitosan modified graphene oxide with MnO2 deposition for high energy density flexible supercapacitors.

To obtain a flexible composite electrode material with excellent electrochemical performance, chitosan (CS)/graphene oxide (GO) composite pretreated from microwave hydrothermal is adopted as the carbon substrate, and MnO2 active material is uniformly deposited on their surface through anodic electrodeposition. In this composite system, CS penetrates into graphene sheets as small molecule units, forming NH-C=O groups with GO via dehydration condensation, which effectively inhibits the stacking of GO and improves the specific surface area, conductivity, as well as the wettability of the carbon support. MnO2 bonding with heteroatom N from CS enables high active material loadings and forms stable three-dimensional network structure, facilitating the enhanced electrochemical performance. Results indicate that increasing depositing MnO2 amount leads to more defective structures of the composite, which promotes their electrochemical performance when used as electrode material. The area specific capacitance of the optimal composite reaches 3553.74 mF/cm2 at 5 mA/cm2 in 1 M Na2SO4 electrolyte. Kinetic analysis shows the energy storage process is capacitance-dominated, with the redox reactions of MnO2 being the main contributor. The prepared asymmetric solid supercapacitor delivers an energy density high up to 0.585 mWh/cm2 at power density of 3000 mW/cm2, and their excellent flexibility makes them promising candidates as flexible sensor.

Ultra-fast synthesis of hierarchical SAPO-11 molecular sieves with the assistance of hydroxyl radicals.

Considering the traditional time-consuming synthesis route and diffusion-limited micropore system of SAPO-11 (i.e., SAPO-11W), a hydroxyl radical assisted method has been developed to prepare hierarchical SAPO-11 within 5 min (i.e., SAPO-11M). Compared to previous reports, the unique contribution is to induce hydroxyl radicals by exposing carbon materials to microwave irradiation in an oxygen-containing atmosphere. Carbon materials play a dual role as mesopore filler and hydroxyl radical initiator. When employed to prepare deoxygenation catalysts for stearic acids, a higher selectivity for C15-C18 and isomers is observed due to the mild acidity of SAPO-11M. The Lewis-rich acidity of SAPO-11M exhibits an electron deficiency to interact with the hydroxyl oxygen atoms and promotes the hydrodeoxygenation of stearic acids with excellent atom economy. These results are important for opening up a new prospect of synthesizing SAPO molecular sieves (e.g., SAPO-11 and SAPO-5) by an efficient and facile route.

Impact of Dipole Effect on Perovskite Solar Cells.

Interface modification and bulk doping are two major strategies to improve the photovoltaic performance of perovskite solar cells (PSCs). Dipolar molecules are highly favored due to their unique dipolarity. This review discusses the basic concepts and characteristics of dipoles. In addition, the role of dipoles in PSCs and the corresponding conventional characterization methods for dipoles are introduced. Then, we systematically summarize the latest progress in achieving efficient and stable PSCs in dipole materials at several key interfaces. Finally, we look forward to the future application directions of dipole molecules in PSCs, aiming at providing deep insight and inspiration for developing efficient and stable PSCs.

Influence of F-Containing Materials on Perovskite Solar Cells.

Perovskite solar cells (PSCs) are usually modified and passivated to improve their performance and stability. The interface modification and bulk doping are the two basic strategies. Fluorine (F)-containing materials are highly favored because of their unique hydrophobicity and coordination ability. This review discusses the basic characteristics of F, and the basic principles of improving the photovoltaic performance and stability of PSC devices using F-containing materials. We systematically summarized the latest progress in the application of F-containing materials to achieve efficient and stable PSCs on several key interface layers. It is believed that this work will afford significant understanding and inspirations toward the future application directions of F-containing materials in PSCs, and provide profound insights for the development of efficient and stable PSCs.

Properties of chitosan-immobilized cellulase in ionic liquid.

The properties of cellulase that was attached to the surface of the chitosan carrier in aqueous-ionic liquid (IL; 1,3-dimeth-ylimidazolium dimethylphosphate) mixture were studied. The optimal temperature for immobilized cellulase in aqueous-IL mixed solutions was 60 °C. The immobilized cellulase acquired the highest relative activity at a ratio of 1:4 (IL to water, v/v), compared to activity levels of 79% and 7%, when the ratio of IL to water (v/v) was 0:1 and 1:0, respectively. At 80 °C, the immobilized cellulase in the aqueous-IL mixture conserved 46.3% activity after 120 Min. The immobilized cellulase can be effectively reused three times. After 4 weeks, the activity of immobilized cellulase maintained 83.5%. The Michaelis constant (Km ) and maximum reaction velocity (Vm ) values for the immobilized cellulase were 4.8 mg/L and 0.156 mg/(mL Min), respectively. To the best of our knowledge, this is the first report on the properties of chitosan-immobilized cellulase in aqueous-IL.

Colonization dynamics in body-size spectrum of protozoan periphytons for marine bioassessment using two modified sampling systems.

The body-size spectrum of microperiphytons has been proved to be a powerful tool for bioassessment. To explore colonization dynamics in body-size spectrum of periphytic protozoa in two modified sampling systems of both glass slide (mGS) and polyurethane foam unit (mPFU), a 28-day colonization survey was conducted in coastal waters of the Yellow Sea, China. A total of 7 body-size ranks were identified from 62 species, with 7 ranks (60 species) in the mGS and 6 ranks (37 species) in the mPFU system. The stable pattern with similar body-size spectra was found earlier in the mGS system than mPFU system during the colonization period. Both the trajectory and bootstrapped average analyses revealed that the colonization dynamics were significantly different in the body-size spectrum between the two methods. Based on our data, it suggests that the mGS system might be a better choice than the mPFU system for bioassessment in marine ecosystems.

Chitosan/graphene oxide hybrid hydrogel electrode with porous network boosting ultrahigh energy density flexible supercapacitor.

To overcome the low energy density and poor conductivity of conventional electrode materials for building supercapacitor, herein, a hybrid hydrogel prepared from compositing bio-based chitosan with holey graphene oxide by microwave-assisted hydrothermal is proposed. This binary hydrogel is endowed with heteroatomic functional groups and conductive porous network by chemical pretreatments, where amides and carboxyl groups are introduced during the acylation modification of chitosan to enable it soluble in water for sufficient reaction, while the oxidation etching for graphene oxide in the defect area by H2O2 facilitates in-plane nanopores network to provide abundant active surface and short ion diffusion pathway. Benefited from the high conductivity and flexibility, this hydrogel present promising performance when used as additive-free electrode in a three-electrode, with a high specific capacitance of 377 F/g at 5 A/g. The rich nitrogen and oxygen groups on surface of the hydrogel contribute to high capacitance directly, while the in-plane nanopores and hierarchically porous network benefit to promote their wettability, accelerate the charge transfer and enhance their charge storage ability. When the hydrogel composite is adopted into a flexible solid-state supercapacitor employing lignin hydrogel electrolyte, it unfolds a specific capacitance of 210 F/g at 0.5 A/g, with an ultrahigh energy density of 31 Wh/kg at the power density of 150 W/kg. The solid-state supercapacitor exhibits promising potential in applications such as signal sensor and portable energy storage.

Ru-Ni Alloy Nanoparticles Loaded on N-Doped Amphiphilic Mesoporous Hollow Carbon@silica Spheres as Catalyst for the Hydrogenation of α-Pinene to cis-Pinane.

N-doped mesoporous carbon spheres (NHMC@mSiO2 ) encapsulated in silica shells were prepared by emulsion polymerization and domain-limited carbonization using ethylenediamine as the nitrogen source, and Ru-Ni alloy catalysts were prepared for the hydrogenation of α-pinene in the aqueous phase. The internal cavities of this nanomaterial are lipophilic, enhancing mass transfer and enrichment of the reactants, and the hydrophilic silica shell enhances the dispersion of the catalyst in water. N-doping allows more catalytically active metal particles to be anchored to the amphiphilic carrier, enhancing its catalytic activity and stability. In addition, a synergistic effect between Ru and Ni significantly enhances the catalytic activity. The factors influencing the hydrogenation of α-pinene were investigated, and the optimum reaction conditions were determined to be as follows: 100 °C, 1.0 MPa H2 , 3 h. The high stability and recyclability of the Ru-Ni alloy catalyst were demonstrated through cycling experiments.

Can tidal events influence analysis on colonization dynamics in body-size spectrum of periphytic ciliates for marine bioassessment?

The tidal influence on body-size spectrum of the protozoan periphytons was explored by using the conventional slide system (CS) and the polyurethane foam enveloped slide system (PFES) in coastal waters during a 1-month study. During the colonization process, clear temporal patterns of the body-size spectrum were observed using the two sampling methods. In terms of relative species number and frequency of occurrence, the rank S4 represented a more stable temporal variability in the PFES system than the CS system during the colonization. Additionally, the small forms (e.g., S1, S2, and S3) were more abundant in the PFES system. The clustering and bootstrapped average analyses demonstrated differences in body-size spectrum of protozoans between the two sampling systems. Our results imply that the body-size spectrum of protozoan periphytons may be impacted by tidal events during colonization process in marine waters.