Electrochemical anodic oxidation assisted fabrication of memristors

Owing to the advantages of simple structure,low power consumption and high-density integration,memristors or memristive devices are attracting increasing attention in the fields such as next generation non-volatile memories,neuromorphic computation and data encryption.However,the deposition of memristive films often requires expensive equipment,strict vacuum conditions,high energy consumption,and extended processing times.In contrast,electrochemical anodizing can produce metal oxide films quickly(e.g.10 s) under ambient conditions.By means of the anodizing technique,oxide films,oxide nanotubes,nanowires and nanodots can be fabricated to prepare memristors.Oxide film thickness,nanostructures,defect concentrations,etc,can be varied to regulate device performances by adjusting oxidation parameters such as voltage,current and time.Thus memristors fabricated by the anodic oxidation technique can achieve high device consistency,low variation,and ultrahigh yield rate.This article provides a comprehensive review of the research progress in the field of anodic oxidation assisted fabrication of memristors.Firstly,the principle of anodic oxidation is introduced;then,different types of memristors produced by anodic oxidation and their applications are presented;finally,features and challenges of anodic oxidation for memristor production are elaborated.

Efficient concentration of trace analyte with ordered hotspot construction for a robust and sensitive SERS platform

Surface-enhanced Raman scattering(SERS)platform,which enables trace analyte detection,has important application prospects.By structuring/modifying the surface of the SERSsubstrate,analyte in highly diluted solutions can be concentrated into localized active areas for highly sensitive detection.However,subject to the difficulty of the fabrication process,itremains challenging to balance hot-spot construction and the concentration capacity of analyte simultaneously.Therefore,preparing SERS substrates with densely ordered hot spots andefficient concentration capacity is of great significance for highly sensitive detection.Herein,we propose an Ag and fluoroalkyl-modified hierarchical armour substrate(Ag/F-HA),which has a double-layer stacking design to combine analyte concentration with hotspot construction.The microarmour structure is fabricated by femtosecond-laser processing to serve as asuperhydrophobic and low-adhesive surface to concentrate analyte,while the anodic aluminium oxide(AAO)template creates a nanopillar array serving as dense and ordered hot spots.Under the synergistic action of hot spots and analyte concentration,Ag/F-HA achieves a detectionlimit down to 10^(-7)M doxorubicin(DOX)molecules with a RSD of 7.69%.Additionally,Ag/F-HA exhibits excellent robustness to resist external disturbances such as liquid splash or abrasion.Based on our strategy,SERS substrates with directional analyte concentrations are further explored by patterning microcone arrays with defects.This work opens a way to the realistic implementation of SERS in diverse scenarios.

Effect of coke properties and its blending recipe on performances of carbon anode for aluminium electrolysis

The properties and blending recipe of petroleum cokes used to make high quality carbon anodes for aluminium electrolysis were studied. Three kinds of green cokes were selected for bench scale study to illustrate the effects of cokes properties and its blending recipe on anode performances. The results show that impurities derived mainly fi＇om cokes remarkably affect the CO2 reactivity and air reactivity of carbon anodes. Ca, Na and V can increase CO2 reactivity of calcined cokes but S has the contrary effect, and the cokes of high V level generally present high air reactivity. The anodes with good quality can be made by properly selecting and scientifically blending of cokes, some poor quality cokes can also be used to produce high quality anodes with a reasonable blending recipe. Na contaminated anodes have high CO2 reactivity and air reactivity, so the recycled anode butts should be well cleaned to reduce Na content before being introduced into anode production, which is especially important to the low S cokes.

Organic molecules modified palladium nanowires arrays prepared by high temperature liquid phase reduction

This paper reports high temperature liquid phase synthesis of Pd nanowires using chemically modified porous anodic aluminium oxide as template. In this synthesis process, oleic acid is used to modify the inner wall of the pores and Pd^2＋ complex with oleylamine is filled into the channel of the template. The complex is then reduced to give oleylamine-capped Pd nanowires. This paper suggests that oleic acid can improve the environment of inner wall of the pores, leading to the formation of uniform Pd nanowires. The synthetic process can be extended to make other types of nanowires.

Long-term deterioration of lubricant-infused nanoporous anodic aluminium oxide surface immersed in NaCl solution

This study investigated the deterioration of a lubricant-infused anodic aluminium oxide surface in a 1M NaCl solution for~200 days.Direct observation by cryo-SEM and quantitative analyses by UV spectroscopy and EIS revealed that the long-term deterioration of the lubricant-infused surface was divided into two stages:the surface-adhered lubricant layer gradually dissolved at a constant rate until the substrate was exposed;afterwards the lubricant infused in the nanochannels began to diffuse and was depleted after~200 days.The EIS results also revealed that the defects reduced the corrosion resistance of the lubricant-infused surface considerably.

Porous Anodic Metal Mxides

Porous anodic aluminium oxide(AAO)and anodic titanium oxide(ATO)attracted an increased attention in the recent years due to their high potentials of application in nanotechnology.This article presents a brief review of some important developments of these smart materials including anodization methods,formation mechanisms of the pores,self-ordering processes and applications.Anodization of other metals are also highlighted.