Abstract
A polyaniline (PANI)-based gel material with a redox-active nature has demonstrated unique charge storage, photovoltaic, and electrochromic properties in the bulk of the gel. The specific capacitance in the volume of the gel was measured to be 428.9 mF g(-1). Also, a hybrid device for concurrent solar energy harvesting and charge storage was made simply by placing a layer of the gel between a TiO2 coated electrode and a carbon electrode. The hybrid device showed 137 mV open circuit voltage under the light condition with only 10 mV voltage drop in 600 s after cessation of light. The electrochromic property of the composite gel was also studied in a device made of two transparent electrodes. The results showed 64 % transmittance at 564 nm and zero transmittance when the cell was biased at 0.0 V and 2.0 V, respectively. The photoelectric property and the redox-active nature of the gel suggest existence of both ionic and electronic conductions through the electrolytes. The results are encouraging to further customize the composite gel for various applications, including supercapacitors, solar cells, photoactive supercapacitors, and electrochromic windows.