Resistive Switching Memory of TiO2 Nanowire Networks Grown on Ti Foil by a Single Hydrothermal Method

The resistive switching characteristics of TiO_2 nanowire networks directly grown on Ti foil by a single-step hydrothermal technique are discussed in this paper. The Ti foil serves as the supply of Ti atoms for growth of the TiO_2 nanowires, making the preparation straightforward. It also acts as a bottom electrode for the device. A top Al electrode was fabricated by e-beam evaporation process. The Al/TiO_2 nanowire networks/Ti device fabricated in this way displayed a highly repeatable and electroforming-free bipolar resistive behavior with retention for more than 10~4 s and an OFF/ON ratio of approximately 70. The switching mechanism of this Al/TiO_2 nanowire networks/Ti device is suggested to arise from the migration of oxygen vacancies under applied electric field. This provides a facile way to obtain metal oxide nanowire-based Re RAM device in the future.

The intricacies of neurotrophic factor therapy for retinal ganglion cell rescue in glaucoma: a case for gene therapy

Regeneration of damaged retinal ganglion cells（RGC） and their axons is an important aspect of reversing vision loss in glaucoma patients. While current therapies can effectively lower intraocular pressure, they do not provide extrinsic support to RGCs to actively aid in their protection and regeneration. The unmet need could be addressed by neurotrophic factor gene therapy, where plasmid DNA, encoding neurotrophic factors, is delivered to retinal cells to maintain sufficient levels of neurotrophins in the retina. In this review, we aim to describe the intricacies in the design of the therapy including： the choice of neurotrophic factor, the site and route of administration and target cell populations for gene delivery. Furthermore, we also discuss the challenges currently being faced in RGC-related therapy development with special considerations to the existence of multiple RGC subtypes and the lack of efficient and representative in vitro models for rapid and reliable screening in the drug development process.

Advances in doping strategies for sodium transition metal oxides cathodes:A review

The electrochemistry of cathode materials for sodium-ion batteries differs significantly from lithium-ion batteries and offers distinct advantages.Overall,the progress of commercializing sodium-ion batteries is currently impeded by the inherent inefficiencies exhibited by these cathode materials,which include insufficient conductivity,slow kinetics,and substantial volume changes throughout the process of intercalation and deintercalation cycles.Consequently,numerous methodologies have been utilized to tackle these challenges,encompassing structural modulation,surface modification,and elemental doping.This paper aims to highlight fundamental principles and strategies for the development of sodium transition metal oxide cathodes.Specifically,it emphasizes the role of various elemental doping techniques in initiating anionic redox reactions,improving cathode stability,and enhancing the operational voltage of these cathodes,aiming to provide readers with novel perspectives on the design of sodium metal oxide cathodes through the doping approach,as well as address the current obstacles that can be overcome/alleviated through these dopant strategies.

Recent progress in application of cobalt-based compounds as anode materials for high-performance potassium-ion batteries

Potassium-ion batteries(KIBs)are regarded as one of the most promising replacements for lithium-ion batteries because of their low cost and high performance.Exploring suitable anode materials to stably and effectively store potassium is critical for the development of KIBs.Given their high theoretical specific capacity,cobalt-based compounds have been extensively investigated as an anode material in recent years;however,specific reviews summarizing the research progress in the application of cobaltbased compounds as anode materials for high-performance KIBs are lacking.Consequently,this review systematically summarizes the recent states of cobalt-based anode materials in KIBs starting at the potassium storage mechanism,followed by strategies and applications to improve the electrochemical performance.The current challenges are also discussed,and corresponding prospects are proposed.This work may facilitate the realization of various applications of cobalt-based compound anodes for highperformance rechargeable batteries and is expected to provide some guidance for developing other metal-based compounds for KIBs anodes.

In-situ conversion of Ni2P/rGO from heterogeneous self-assembled NiO/rGO precursor with boosted pseudocapacitive performance

Two-dimensional(2 D)heterostructural Ni2 P/rGO is successfully fabricated by in-situ phosphating selfassembled NiO/rGO composites and shows the enhanced electrochemical performances.In this design,the rGO sheets effectively reduce the lattice strain created during the phase transformation from NiO to Ni2 P,thereby maintaining ultrathin nanostructures of Ni2 P.The resulting Ni2 P/rGO layered heterostructure gives the composite plenty of pores or channels,good electrical conductivity and well-exposed active sites.Density functional theory(DFT)calculation further demonstrates that the Fermi energy level and electron localize of near Ni atoms in Ni2 P is higher than that of NiO,which endow Ni2 P with faster and more reversible redox reactivity in dynamic.Benefiting from their structural and compositional merits,the as-synthesized Ni2 P/rGO exhibits high specific discharge capacity and excellent rate performance.Furthermore,a hybrid supercapacitor built with Ni2 P/rGO and activated carbon shows a high specific energy of 38.6 Wh/kg at specific power of 375 W/kg.

SYNTHESIS AND CHARACTERIZATION OF Fe(Ⅱ-COORDINATED PS-b-P[NIPAM-co-(VBC-Fe-DMAP)]BLOCK COPOLYMERS

In this work, a new type of block polymers, polystyrene-b-poly[（N-isopropyl acrylamide）-co-（vinyl benzyl chloride）] （PS-b-P（NIPAM-co-VBC））, was prepared via reversible addition fragmentation transfer polymerization, then pentacyano（4-（dimethylamino pyridine））ferrate （Fe-DMAP） was attached to VBC units through a quatemization process. The Fe（II）-coordinated PS-b-P[NIPAM-co-（VBC-Fe-DMAP）] block copolymers were characterized by 1H-NMR, FT-IR and TGA. The self-assembly behavior of the block copolymers was also investigated and the micelle morphology was characterized by TEM. It was found that the PS-b-P（NIPAM-co-VBC） block polymer and Fe-coordinated block copolymer could both form spherical micelles in DMF/MeOH mixed solvent.

Wood-derived biochar as thick electrodes for high-rate performance supercapacitors

Developing effective electrodes with commercial-level active mass-loading(>10 mg cm^(−2))is vital for the practical application of supercapacitors.However,high active mass-loading usually requires thick active mass layer,which severely hinders the ion/electron transport and results in poor capacitive performance.Herein,a self-standing biochar electrode with active mass-loading of ca.40 mg cm^(−2) and thickness of 800μm has been developed from basswood.The basswood was treated with formamide to incorporate N/O in the carbon structure,followed by mild KOH activation to ameliorate the pore size and introduce more O species in the carbon matrix.The as-prepared carbon monoliths possess well conductive carbon skeleton,abundant N/O dopant and 3D porous structure,which are favorable for the ion/electron transport and promoting capacitance performance.The self-standing carbon electrode not only exhibits the maximum areal/mass/volumetric specific capacitance of 5037.5 mF cm^(−2)/172.5 F g^(−1)/63.0 F cm^(−3) at 2 mA cm^(−2)(0.05 A g^(−1)),but also displays excellent rate performance with 76%capacitance retention at 500 mA cm^(−2)(12.5 A g^(−1))in a symmetric supercapacitor,surpassing the state-of-art biomass-based thick carbon electrode.The assembled model can power typical electron devices including a fan,a digital watch and a logo made up of 34 light-emitting diodes for a proper period,revealing its practical application potential.This study not only puts forward a commercial-level high active mass-loading electrode from biomass for supercapacitor,but also bridges the gap between the experimental research and practical application.