Latest ArticlesThermoelectric (TE) materials enable effective and direct energy conversions between heat and electricity, displaying wide applications including waste/low-grade heat harvesting, local cooling, sensing and wearable electronics. Among the recently-developed organic and composite TE materials, poly(3,4-ethylenedioxythiophene) (PEDOT) is perhaps the most successful and frequently reported type. Herein, we aim to review the recent advances of the synthesis, mechanism and applications of PEDOT-based TE composites. First, the research background and the history of TE materials are briefly introduced. Next, the synthesis and TE performance of PEDOT-based composites are summarized according to the sequence of films, hydrogels/aerogels and fibers/yarns. Then, the mechanism, structure and property are elucidated. After that, the recent development and its applications of power generation and sensing are highlighted. Finally, we provide an outlook on the prospects and the challenges of PEDOT-based TE composites.
Owing to the spread of COVID-19, it is difficult to ignore the existence and importance of antimicrobial polymers (AMPs) because most protective appliances are made of polymers. Generally, bacteria prefer hydrophilic compounds, while fungi prefer hydrophobic ones. In recent decades, AMPs have made significant strides due to the versatile design of the functional groups or units for hydrophilic, hydrophobic, or amphiphilic performances. This review summarizes the advances of AMPs itself from the perspective of their wettability. Moreover, this study aims to clarify how the functional groups determine the interaction between the polymer and microorganisms directly affects the antimicrobial efficacy of the designed polymers. Based on the advances, the challenges and outlooks of AMPs from the perspective of wettability are systematically discussed to build a bridge between the structural design of AMPs and the requirements of practical applications.
Maximizing solar energy utilization is a persistent challenge in photo catalysis, which determines sustainable solar-driven photocatalytic process. Photo thermal-coupled photo catalysis is considered as a promising solution to tackle the issues of sustainable energy scarcity and environmental pollution by harvesting the full-spectrum solar energy. Herein, a highly efficient photo thermal-accelerated photo catalysis system is elaborately established, in which the assembled carbonized stick/Nb2C MXene evaporator can heat water into vapor and the integrated g-C3N4 photocatalyst further enables high-efficiency photocatalytic hydrogen production. The designed hyperboloid wood-based architecture possesses a multiphase interface of water steam/catalyst/hydrogen to reduce the transport resistance of hydrogen gas in liquid and ultimately maximize the output of hydrogen energy. Consequently, this coupled photothermal-photocatalytic system achieves a stable solar evaporation rate of 2.16 kg m-1 h-1 under one sun irradiation and highly efficient hydrogen-evolving rate of 3096 µmol g-1 h-1. This work paves a way to explore the improvement of photocatalytic hydrogen production by synergic photothermal effect for potential applications in renewable solar energy utilization and hydrogen production.
The clustered regularly interspersed short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) system is an RNA-guided platform for highly efficient and specific genome targeting in diverse organisms, which has been exploited for various applications in gene manipulation. Compared with the constantly active CRISPR/Cas9 function, conditional control of its activity can improve the performance of the system with reduced side effects and high spatiotemporal precision. The pH-responsive triplex RNA was successful used in CRISPR-derived RNA/trans-activating crRNA (crRNA/tracrRNA) of CRISPR/Cas9, thus affecting RNA/dead Cas9 (dCas9) complex to target DNA in vitro and in vivo. This design of triplex RNA opens a new window towards the broad involvement of eukaryotic cells for conditional control of CRISPR/Cas9 function.
A simple and additive-free protocol has been developed for the preparation of β-keto phosphorodithioates through the three-component reaction of easily available sulfoxonium ylides, P4S10, and alcohols. The present geminal hydro-phosphorodithiolation reaction was performed at room temperature to construct a series of β-keto phosphorodithioates in the absence of any metal reagents, bases, or additives.
In recent years, FeCl3-photocatalyzed direct C–H/Si–H bond functionalization reactions have attracted huge attention. In those transformations, chlorine radical (Cl•) could be generated from FeCl3 via a ligand-to-metal charge transfer (LMCT)/homolysis process under light irradiation. The resulting chlorine radical subsequently acts as a hydrogen atom transfer (HAT) agent to abstract the hydrogen atom of aliphatic C–H, O–H, or Si–H bonds to give the corresponding C/Si/O-centered radicals for various organic transformations. In this review, we summarized the recent advances in the application of FeCl3 as a HAT photocatalyst for the C/Si–H functionalization to construct C–C, C–N, C–Si, C–S, C–B, and C-P bonds.
Biomass absorbing materials have received increasing attention for electromagnetic wave (EMW) absorption field absorbing materials due to its low density and high dielectric loss. However, the biomass EMW absorbing materials often suffer from the insufficient magnetic loss and impedance matching. In this work, a facile ZIF-8/ZIF-67-derived biomass composites (CoZnO@BPC) was prepared for high-performance EMW absorption based on multi-component micro, nano structures metal particles and xanthoce sorbifolia bunge shells-derived biomass porous carbon (BPC). The dielectric loss and/or magnetic loss abilities of CoZnO@BPC composites were adjusted by changing the mass ratio of Zn2+ to Co2+ ions. Under the filled amount of 20 wt%, CoZnO@BPC exhibited excellent EMW absorption with the minimum reflection loss (RL) at 15.84 GHz is -50.2 dB, and the matching thickness is only 1.7 mm. By adjusting the ZIFs mass ratio, the effective absorption bandwidth (EAB) can be up to 5.92 GHz (from 12.08 GHz to 18 GHz), and the matching thickness is only 1.9 mm. The results provide a new insight for the economical and efficient preparation of lightweight and advanced microwave absorbing materials.
The O3-Na0.85Ni0.2Fe0.4Mn0.4O2 layered oxide cathode material possesses the advantages of high specific capacity, low cost, and simple synthesis. However, sluggish kinetics and complicated phase transition caused by the large size difference between Na+ and tetrahedral gaps lead to poor rate and cycling performance. Therefore, a scalable and feasible strategy was proposed to modulate local chemical environment by introducing Mg2+ and B3+ into O3-Na0.85Ni0.2Fe0.4Mn0.4O2, which can distinctly improve kinetic transport rate as well as electrochemical performance. The capacity retention of O3-(Na0.82Mg0.04)(Ni0.2Fe0.4Mn0.4)B0.02O2 (NFMB) increases from 43.3% and 12.4% to 89.5% and 89.0% at 1 C and 3 C after 200 cycles, respectively. Moreover, the electrode still delivers high rate capacity of 93.9 mAh/g when current density increases to 10 C. Mg2+ ions riveted on Na layer act as a "pillar" to stabilize crystal structure and inhibit structural change during the desodiumization process. B3+ ions entering tetrahedral interstice of the TM layer strengthen the TM-O bond, lower Na+ diffusion energy barrier and inhibits the slip of TM layer. Furthermore, the assembled full batteries with the modified cathode material deliver a high energy density of 278.2 Wh/kg with commercial hard carbon as anode. This work provides a strategy for the modification of high-performance SIB layered oxide materials to develop the next-generation cost-effective energy storage grid systems.
We describe a versatile electrophile addition/SPR sequence of readily available cyclopropyl carbinols that affords multi-substituted carbonylated cyclopropanes with high stereo-fidelity. This approach tolerates various heteroatom electrophiles, migration of carbon moiety of all possible hybridization states, facile ring reorganization and natural compound valorization. The examples represent an unprecedented version of SPR wherein migration to a non-benzylic bulky tertiary carbo-cation is realized with promising enantiocontrol.
A highly site-selective intermolecular trifluoromethylimination of activated and unactivated olefins was reported under transition-metal- and photosensitizer-free conditions. This newly developed strategy provides straightforward and efficient access to diverse value-added vicinal trifluoromethyl amines without resorting to the pre-functionalized reagents. Mechanistic experiments demonstrate that the approach proceeded through CF3 and iminyl two-radicals process, which were generated directly from commercially available benzophenone imine in a novel electron-donor mode via a SET process activated by the bifunctional hypervalent iodine reagents. The synthetic potential of the protocols was further showcased via the condensation/amination sequential cascade, and transformations to access β-CF3 primary amines.