Layered Low‐Dimensional Ruddlesden‐Popper and Dion‐Jacobson Perovskites: From Material Properties to Photovoltaic Device Performance

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Layered Low-Dimensional Ruddlesden-Popper and Dion-Jacobson Perovskites: From Material Properties to Photovoltaic Device Performance

Phase is different: Recent progress on low dimensional perovskite materials based on Ruddlesden-Popper and Dion-Jacobson phases is reviewed and the key link between the phase difference and the optoelectronic performance is critically summarized.


Abstract

Layered low-dimensional halide perovskites (LDPs) with multiple quantum well structure have shown increasing research interest in photovoltaic solar cell applications owing to their intrinsic moisture stability and favorable photophysical properties in comparison with their three-dimensional (3D) counterparts. The most common LDPs are Ruddlesden-Popper (RP) phases and Dion-Jacobson (DJ) phases, both of which have made significant research advances in efficiency and stability. However, distinct interlayer cations between RP and DJ phase lead to disparate chemical bonds and different perovskite structures, which endow RP and DJ perovskite with distinctive chemical and physical properties. Plenty of reviews have reported the research progress of LDPs but no summary has elaborated from the perspective of the merits and drawbacks of the RP and DJ phases. Herein, in this review, we offer a comprehensive expound on the merits and promises of RP and DJ LDPs from their chemical structure, physicochemical properties, and photovoltaic performance research progress aiming to provide a new insight into the dominance of RP and DJ phases. Then, we reviewed the recent progress on the synthesis and implementation of RP and DJ LDPs thin films and devices, as well as their optoelectronic properties. Finally, we discussed the possible strategies to resolve existing toughs to realize the desired high-performance LDPs solar cells.

Co3O4 Supported on β‐Mo2C with Different Interfaces for Electrocatalytic Oxygen Evolution Reaction

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Co3O4 Supported on β-Mo2C with Different Interfaces for Electrocatalytic Oxygen Evolution Reaction

“Heterogeneous electrocatalytic water oxidation is a complicate reaction… This and more about the story behind the research that inspired the Cover image is presented in the Cover Profile. Read the full text of the corresponding research at 10.1002/cssc.202300709. View the Front Cover here: 10.1002/cssc.202301261.


Abstract

Invited for this month′s cover is the group of Rui Cao at Shaanxi Normal University. The image shows the interface between Co3O4 and β-Mo2C can be regulated to boost the electrocatalytic performance of water oxidation. The Research Article itself is available at 10.1002/cssc.202300709.

A High‐Potential Bipolar Phenothiazine Derivative Cathode for Aqueous Zinc Batteries

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A High-Potential Bipolar Phenothiazine Derivative Cathode for Aqueous Zinc Batteries

A novel molecule (PTDM) containing n-type and p-type redox sites was prepared. By exploiting the synergistic advantages of two-type redox sites of PTDM, the aqueous PTDM//Zn cell delivers a high average voltage of ~1.13 V, a decent specific capacity of 118.3 mAh g−1 at 0.1 A g−1 and moderate capacity retention of 65.6 % over 6400 cycles at 1 A g−1.


Abstract

Aqueous zinc ion batteries (AZIBs) are gaining popularity as advanced energy storage devices that are economical, safe, and use resource-abundant storage options. In this study, we have synthesized a bipolar phenothiazine organic scaffold known as 3,7-bis(melaminyl)phenothiazin-5-ium iodide (PTDM), which is obtained by undergoing nucleophilic substitution through phenothiazinium tetraiodide hydrate (PTD) and melamine. Electrochemical results indicate that PTDM can act as a high-potential cathode material for rechargeable AZIBs. In detail, the aqueous PTDM//Zn full cell exhibits a high average voltage of approximate 1.13 V, along with a specific capacity of 118.3 mAh g−1 at 0.1 A g−1. Furthermore, this demonstrated cell displays moderate long-term cycling stability over 6400 cycles, which is encouraging and suggests potential for developing advanced organic electrode materials for rechargeable AZIBs.

Fabrication of Hematite Photoanode Consisting of (110)‐Oriented Single Crystals

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Fabrication of Hematite Photoanode Consisting of (110)-Oriented Single Crystals

Single crystal hematite photoanode, Fe-25A/Co−Pi, yields a photocurrent density of 2.67 mA cm−2 (at 1.23 V vs. RHE) and an incident photon-to-current conversion efficiency incident photon-to-current conversion efficiency (IPCE) value of 50.8 % (380 nm) under AM 1.5G light irradiation, which is much higher than that obtained from the commonly used by thermal dehydration from β-FeO(OH) precursors.


Abstract

In this work, α-Fe2O3 photoanode consisted of (110)-oriented α-Fe2O3 single crystals were synthesized by a facile hydrothermal method. By using particular additive (C4MimBF4) and regulation of hydrothermal reaction time, the Fe-25 consisted of a single-layer of highly crystalline (110)-oriented crystals with fewer grain boundaries, which was vertically grown on the substrate. As a result, the charge separation efficiency and photoelectrochemical (PEC) performance of Fe-25A (Fe-25 after dehydration treatment) have been greatly improved. Fe-25A yields a photocurrent of 1.34 mA cm−2 (1.23 V vs RHE) and an incident photon-to-current conversion efficiency (IPCE) of 31.95 % (380 nm). With the assistance of cobalt–phosphate water oxidation catalyst (Co−Pi), the PEC performance could be further improved by enhancing the holes transfer at electrode/electrolyte interface and inhibiting surface recombination. Fe-25A/Co−Pi yields a photocurrent of 2.67 mA cm−2 (1.23 V vs RHE) and IPCE value of 50.8 % (380 nm), which is 3.67 times and 2.39 times as that of Fe-2A/Co−Pi. Our work provides a simple method to fabricate highly efficient Fe2O3 photoanodes consist of characteristic (110)-oriented single crystals with high crystallinity and high quality interface contact to enhance charge separation efficiencies.

Optimizing Li‐ion Solvation in Gel Polymer Electrolytes to Stabilize Li‐Metal Anode

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Optimizing Li-ion Solvation in Gel Polymer Electrolytes to Stabilize Li-Metal Anode

A novel gel polymer electrolyte (GPE) for lithium metal batteries (LMBs) combines two strategies: in-situ formation of GPEs and regulating SEI by adding diluent to manipulate ion pairing. Through a series of experiments and molecular modeling, the fundamental mechanisms of how the diluent TTE affects the ion solvation in the GPE and the formation of SEI on the Li-metal surface were investigated.


Abstract

Gel polymer electrolytes (GPEs) have potential as substitutes for liquid electrolytes in lithium-metal batteries (LMBs). Their semi-solid state also makes GPEs suitable for various applications, including wearables and flexible electronics. Here, we report the initiation of ring-opening polymerization of 1,3-dioxolane (DOL) by Lewis acid and the introduction of diluent 1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether (TTE) to regulate electrolyte structure for a more stable interface. This diluent-blended GPE exhibits enhanced electrochemical stability and ion transport properties compared to a blank version without it. FTIR and NMR proved the effectiveness of monomer polymerization and further determined the molecular weight distribution of polymerization by gel permeation chromatography (GPC). Experimental and simulation results show that the addition of TTE enhances ion association and tends to distribute on the anode surface to construct a robust and low-impedance SEI. Thus, the polymer battery achieves 5 C charge-discharge at room temperature and 200 cycles at low temperature −20 °C. The study presents an effective approach for regulating solvation structures in GPEs, promoting advancements in the future design of GPE-based LMBs.

Conjugated Olefin Enabled Rollover Cyclometallation of Distant C‐H Bonds: Regioselective Annulation of o‐Alkenyl Phenols with Alkynes

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Although challenging, the distant C-H functionalization with precision is quite rewarding and has long been intriguing. Tailoring an appropriate template accomplishes the job but the prerequisite sets the limitation. We herein unveil our discovery of annulation of alkynes on to two distant (from directing group) C-H bonds through rollover cyclometallation assisted by conjugated C=C bond. The annulation follows a concomitant cyclization rewarding a rare triple C-H functionalization. The annulation is totally regioselective with an array of unsymmetrical alkynes, taking the leverage of an extended conjugation or a tertiary hydroxyl co-ordination. The mechanism is supported by control experiments, KIE & labelling studies and Mass spectrometry.

Establishing modular cell‐free expression system for the biosynthesis of bicyclomycin from a chemically synthesized cyclodipeptide

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Comprehensive Summary

Cell-free expression systems have emerged as a versatile and powerful platform for metabolic engineering, biosynthesis and synthetic biology studies. Nevertheless, successful examples of the synthesis of complex natural products using this system are still limited. Bicyclomycin, a structurally unique and complex diketopiperazine alkaloid, is a clinically promising antibiotic that selectively inhibits the transcription termination factor Rho. Here, we established a modular cell-free expression system with cascade catalysis for the biosynthesis of bicyclomycin from a chemically synthesized cyclodipeptide. The six cell-free expressed biosynthetic enzymes, including five iron- and α-ketoglutarate-dependent dioxygenases and one cytochrome P450 monooxygenase, were active in converting their substrates to the corresponding products. The co-expressed enzymes in the cell-free module were able to complete the related partial pathway. In vitro biosynthesis of bicyclomycin was also achieved by reconstituting the entire biosynthetic pathways (i.e., six enzymes) using the modular cell-free expression system. This study demonstrates that the modular cell-free expression system can be used as a robust and promising platform for the biosynthesis of complex antibiotics.

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gem‐Difluoroolefination of Amides

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A metal-free one-pot process for the gem-difluoroolefination of amides is described. The reaction is based on interaction of generated in situ α-chloroiminium salts with difluorinated phosphorus ylide formed from difluorocarbene and triphenylphosphine. The olefination involves nucleophile-assisted dephosphorylation and proceeds within one hour at low temperature. The gem-difluoroenamines were used in further transformations leading to a variety of fluoroalkylated amines.