Create Rich Oxygen Defects of Unique Tubular Hierarchical Molybdenum Dioxide to Modulate Electron Transfer Rate for Superior High-Energy Metal-Ion Hybrid Capacitor

Metal-ion capacitors could merit advantages from both batteries and capacitors,but they need to overcome the severe restrictions from their sluggish reaction kinetics of the battery type electrode and low specific capacitance of capacitor type electrode for both high energy and power density.Herein,we use the Kirkendall effect for the first time to synthesize unique tubular hierarchical molybdenum dioxide with encapsulated nitrogen-doped carbon sheets while in situ realizing phosphorus-doping to create rich oxygen vacancies(P-MoO_(2-x)@NP-C)as a sodium-ion electrode.Experimental and theoretical analysis confirm that the P-doping introduced oxygen defects can partially convert the high-bond-energy Mo–O to low-bond-energy Mo–P,resulting in a low oxidation state of molybdenum for enhanced surface reactivity and rapid reaction kinetics.The as-prepared P-MoO_(2-x)@NP-C as an ion-battery electrode is further used to pair active N-doped carbon nanosheet(N-C-A)electrode for Na-ion hybrid capacitor,delivering excellent performance with an energy density of 140.3 Wh kg^(−1),a power density of 188.5 W kg^(−1)and long stable life in non-aqueous solution,which ranks the best among all reported MoO x-based hybrid capacitors.P-MoO_(2-x)@NP-C is also used to fabricate a zinc-ion hybrid capacitor,also accomplishing a remarkable energy density of 43.8 Wh kg^(−1),a power density of 93.9 W kg^(−1),and a long stable life@2A g^(−1)of 32000 cycles in aqueous solutions,solidly verifying its universal significance.This work not only demonstrates an innovative approach to synthesize high-performance metal ion hybrid capacitor materials but also reveals certain scientific insights into electron transfer enhancement mechanisms.

Interfacial modification using the cross-linkable tannic acid for highly-efficient perovskite solar cells with excellent stability

Although the performance of perovskite solar cells(PSCs)has been dramatically increased in recent years,stability is still the main obstacle preventing the PSCs from being commercial.PSC device instability can be caused by a variety of reasons,including ions diffusion,surface and grain boundary defects,etc.In this work,the cross-linkable tannic acid(TA)is introduced to modify perovskite film through post-treatment method.The numerous organic functional groups(–OH and C=O)in TA can interact with the uncoordinated Pb^(2+)and I^(-)ions in perovskite,thus passivating defects and inhibiting ions diffusion.In addition,the formed TA network can absorb a small amount of the residual moisture inside the device to protect the perovskite layer.Furthermore,TA modification regulates the energy level of perovskite,and reduces interfacial charge recombination.Ultimately,following TA treatment,the device efficiency is increased significantly from 21.31%to 23.11%,with a decreased hysteresis effect.Notably,the treated device shows excellent air,thermal,and operational stability.In light of this,the readily available,inexpensive TA has the potential to operate as a multipurpose interfacial modifier to increase device efficiency while also enhancing device stability.

Ionic liquid derived electrocatalysts for electrochemical water splitting

Hydrogen production from electrochemical water splitting is a promising strategy to generate green energy,which requires the development of efficient and stable electrocatalysts for the hydrogen evolution reaction and the oxygen evolution reaction(HER and OER).Ionic liquids(ILs)or poly(ionic liquids)(PILs),containing heteroatoms,metal-based anions,and various structures,have been frequently involved as precursors to prepare electrocatalysts for water splitting.Moreover,ILs/PILs possess high conductivity,wide electrochemical windows,and high thermal and chemical stability,which can be directly applied in the electrocatalysis process with high durability.In this review,we focus on the studies of ILs/PILs-derived electrocatalysts for HER and OER,where ILs/PILs are applied as heteroatom dopants and metal precursors to prepare catalysts or are directly utilized as the electrocatalysts.Due to those attractive properties,IL/PIL-derived electrocatalysts exhibit excellent performance for electrochemical water splitting.All these accomplishments and developments are systematically summarized and thoughtfully discussed.Then,the overall perspectives for the current challenges and future developments of ILs/PILs-derived electrocatalysts are provided.

Net-C18:A Predicted Two-Dimensional Planar Carbon Allotrope and Potential for an Anode in Lithium-Ion Battery

Net-C18,a predicted two-dimensional(2D)graphene-like carbon allotrope,is investigated via first-principles calculations.Its space group is Pmmm.There are 18 carbon atoms per cell.Net-C18 has five-,six-,and eight-membered rings.Net-C18 may be formed by adding even pairs of carbon atoms on the top of hexagons to reconstruct new five-and eight-membered rings,extending the strategy of Haeckelite.Compared to that of graphene(-9.28 e V atom^(-1)),the total energy of net-C18(-9.15 e V atom^(-1))is only 0.13 e V atom^(-1)higher,revealing that net-C18 is energetically metastable.The calculations of phonon and ab initio molecular dynamics(AIMD)demonstrate dynamical and thermal stability of net-C18.The independent elastic constants of net-C18 meet the criterial for the mechanical stability of 2D structure.Its in-plane stiffness along x or y axis is comparably large.The AIMD results reveal that net-C18 has good thermal stability at 1500 K.The band structure also demonstrates that it is metallic.Furthermore,the diffusion of Li atoms on net-C18 has a low energy barrier(0.32 e V),and net-C18 has a low open-circuit voltage(0.024 V)and a high theoretical specific capacity(403 m Ah g^(-1)).Thus,net-C18 may provide high-temperature resistant,flexible electrode in electronics and a promising metallic anode in lithium-ion battery.The proposed formation of net-C18 may open a new pattern defect for the designs of new carbon allotropes.

Screen-printing of Bi2S3 Nanowires on Silk Fabrics for the Construction of Flexible Optical Switch

Wearable electronics has been one of the hottest research topics in recent years and fabric is regarded as a very promising substrate for the wearable units because of its excellent wearability.So far,there is no report on the construction of a fabric-based optical switch.In the present work we fabricate a silk fabric-based optical switch via screen-printing of silver interdigital electrode and Bi2S3 nanowires network layer.Bi2S3 NWs with

Recent advances in engineered polymeric materials for efficient photodynamic inactivation of bacterial pathogens

Nowadays,infectious diseases persist as a global crisis by causing significant destruction to public health and the economic stability of countries worldwide.Especially bacterial infections remain a most severe concern due to the prevalence and emergence of multi-drug resistance(MDR)and limitations with existing therapeutic options.Antibacterial photodynamic therapy(APDT)is a potential therapeutic modality that involves the systematic administration of photosensitizers(PSs),light,and molecular oxygen(O_(2))for coping with bacterial infections.Although the existing porphyrin and non-porphyrin PSs were effective in APDT,the poor solubility,limited efficacy against Gram-negative bacteria,and non-specific distribution hinder their clinical applications.Accordingly,to promote the efficiency of conventional PSs,various polymer-driven modification and function-alization strategies have been adopted to engineer multifunctional hybrid phototherapeutics.This review as-sesses recent advancements and state-of-the-art research in polymer-PSs hybrid materials developed for APDT applications.Further,the key research findings of the following aspects are considered in-depth with constructive discussions:i)PSs-integrated/functionalized polymeric composites through various molecular in-teractions;ii)PSs-deposited coatings on different substrates and devices to eliminate healthcare-associated in-fections;and iii)PSs-embedded films,scaffolds,and hydrogels for regenerative medicine applications.

Nano-functionalized Silk for Smart Wearable Devices

With rapid advances of miniaturization and wireless technologies,electronics has been associated with traditional textiles to develop smart wearable devices for daily health monitoring and fitness tracking 1-2.It is of great demand to fabricate flexible materials that possess both wearability and prac-

Sulfonyldibenzene-based hole-transporting materials for efficient n-i-p perovskite solar cells

Organic hole-transporting materials(HTMs)are an essential component in conventional perovskite solar cells(PSCs).In this work,two sulfonyldibenzene-based molecules,named CS-04 and CS-05,are synthesized and employed as HTMs in n-i-p PSCs.In comparison with CS-04,the carbazole-substituted methoxytriphenylamine(Cz MOTPA)group in CS-05 exhibits an increased degree of molecular distortion,thus endowing CS-05 with excellent solvent solubility and film-formation ability.Moreover,CS-05 shows a high hole mobility,superior hole extraction and hole transporting properties.As a result,CS-05 yields impressive device performances with a high power conversion efficiency(PCE)of 20.15%,while that of CS-04 based device is 19.50%,which is comparable to that of the Spiro-OMe TAD based control device(19.59%).This finding illustrates the potential of sulfonyldibenzene-based molecules for the applications in PSCs,and also provides a novel avenue to improve the performances and stability of PSCs by tailoring the sulfonyldibenzene-based molecules.