Fabricated Micro-nanostructures Polyaniline And Characterization Of Their Electrochemical Performance

Polyaniline（PANI）,one type of promising materials for energy conversion,chemical and biological sensing,microelectronic devices and catalysis,has attracted interesting studies due to its good flexibility and bendability,low cost,good environmental stability,and easy fabrication for large-scale devices.Here,polyaniline nanofibers,cabbage-like polyaniline,urchin-like polyaniline and PANI nanofiber arrays are prepared,which expects to make a significant contribution to the advancement of chemical pseudocapacitor technology due to their high pseudocapacitive behavior and electrochemical stability.1.Here we reported a simple route to synthesize the polyaniline nanofibers with diameter about 150 nm.In this strategy,the PANI nanofibers were fabricated by electrochemical deposition by using two-electrode configuration in 0.01 M aniline and 0.01M H₂SO₄ electrolytes.The as-prepared materials were confirmed by scanning electron microscopy（SEM）,infrared spectroscopy（IR）,Raman spectroscopy and thermogravimetric analysis（TGA）.The electrochemical properties of the PANI nanofibers electrode as supercapacitor materials were investigated.The PANI nanofibers electrode showed high capacitance of 485 F g^-1 at 10 mV/s and the decrease in the specific capacitance is³.5%in 1000 cycles indicated that the PANI nanofiber electrodes show high stability and retain its electrochemical capacitance property over 1000 cycles,suggested promising application of the PANI nanofibers in high-performance supercapacitors.2.We explore a novel route to fabricate cabbage-like polyaniline by in situ polymerization of aniline using the hydroxylated poly（methyl methacrylate）nanospheres（i.e.PMMA-OH-NS）as a template.A maximum specific capacitance of 584 F g^-1(the current density is 0.1 A g^-1)is achieved at 10 mV s₁ as well as a high stability of over 3000cycles（the decrease in the SC is⁹.1%）,which suggests the potential application of the cabbage-like polyaniline in supercapacitors.The predominant electrochemical performances of the cabbage-like polyaniline can be attributed to their large surface area and larger-scale p-p conjugated system present in the quinoid structure of the PANI molecular chain,which can drastically facilitate electron diffusion and improve the utilization of the electroactive PANI during the charge/discharge processes.Accordingly,the facility of charge transfer can decrease resistance along with the PANI molecular chain to improve the electrochemical stability and achieve high-capacitance response characteristics.The present study introduces a new synthesis method for the development of various morphology of other conducting polymer,which may find potential applications in a variety of high-performance electrochemical devices3.The urchin-like polyaniline microsphere was polymerized using the sulfonated polystyrene microspheres（i.e.SPS）as template,and its structure was successfully conformed by the X-ray photoelectron spectrum,Raman spectrum,Ultraviolet-visible spectrum,and TGA thermogram.The urchin-like PANI microspheres with uniform diameter（1.5μm）can be observed on scanning electron microscopy（SEM）.Cyclic voltammetry and galvanostatic charge/discharge tests were carried out to investigate the electrochemical properties of as-prepared urchin-like PANI microspheres.It showed that the specific capacitance（SC）was 435 F g^-1 at a scan rate of 10 mVs^-1,and also exhibited good capability and cycling stability with capacitance retentions of 93%after 1000 cycles,which is superior or close to some individual PANI nanostructures and PANI composite materials.This facile approach is feasible and easy to fabricat microstructural conducting polymer for supercapacitor electrode materials.4.The oriented 1D nanostructure arrays of PANI have great potential applications in various devices.In this communication,we report a simple and facile one-step template-free way to assemble highly oriented arrays of PANI nanofibers using chemical oxidative polymerization on the glass and polymer flexible substrates.The diameters of the individual nanofibers range from 50 nm to 60 nm,and the average length of the aligned nanofibers is up to 120¹50 nm.The PANI nanofiber arrays can be uniformly distributed on the whole substrates via this method,which are confirmed by the results of SEM images and Raman mapping.The as-prepared PANI nanofiber arrays can be potentially used in flexible low-voltage electronics,anti coatings,self-cleaning surfaces and chemical sensors,and so on.