Improvement of electrochemical performance of titania nanowires for supercapacitor electrodes by in-situ growth of polyaniline nanoparticles

Abstract Supercapacitors with excellent electrochemical performance are considered the most promising candidates to meet the increasing energy demand. Herein, we developed a novel electrode material for supercapacitors, polyaniline (PANI)-3-aminopropyl triethoxysilane (APTEs)-titania nanowires (TNW), which was synthesized on potassium doped titanium foil via a simple two-step procedure. In the composite, the nano-mesh structure formed by APTEs-coated TNW serves as the framework for the growth of PANI nanoparticles, and PANI nanoparticles act as the electrochemically active part. The specific capacitance of PANI-APTEs-TNW of up to 315.16 mF cm−2 at 0.2 mA cm−2 in 1.0 M H2SO4 solution is achieved, while that of PANI-TNW is 271.67 mF cm−2. Meanwhile, the capacitance retention rate of PANI-APTEs-TNW is 86.8% after 1000 cycles under 1.5 mA cm−2. Compared to PANI-TNW, the better capacitive behavior of PANI-APTEs-TNW is attributed to the anchoring effect of APTEs, which is highly interactive and exhibits compact structures between the TNW and PANI nanoparticles, resulting in a stable structure during the rapid charge-discharge process. This strategy is characterized by its good electrochemical properties, simple equipment, low cost of raw materials, and large-area preparation. Thus, our findings provide an effective method for the design of high-performance supercapacitors and promote their practical applications.