Changing the morphology of polyaniline from a nanotube to a flat rectangular nanopipe by polymerizing in the presence of amino-functionalized reduced graphene oxide and its resulting increase in photocurrent

• Published in: Carbon (New York) 2013-02, Vol.52, p.509-519
• Main Authors: Chatterjee, Shreyam, Layek, Rama K., Nandi, Arun K.
• Format: Article
• Language: English
• Subjects: Applied sciences; Cross-disciplinary physics: materials science; rheology; Energy; Exact sciences and technology; Graphene; Materials science; Morphology; Nanocomposites; Nanomaterials; Nanoscale materials and structures: fabrication and characterization; Nanostructure; Nanotubes; Natural energy; Photocurrent; Photoelectric effect; Photovoltaic conversion; Physics; Scanning electron microscopy; Solar cells. Photoelectrochemical cells; Solar energy
• ISSN: 0008-6223; 1873-3891
• DOI: 10.1016/j.carbon.2012.10.003

Amino-functionalized reduced graphene oxide (a-RGO) is used to change the morphology of polyaniline (PANI) and to increase the photocurrent in the PANI–a-RGO hybrid. The PANI morphology is changed from a nanotube to a flat rectangular nanopipe (FRNP) by the polymerization of aniline with a-RGO in acetic acid. Scanning (SEM) and transmission electron microscopy show the formation of FRNP morphology which varies by changing the PANI/a-RGO ratio in the hybrid. Time dependent SEM and Fourier transform infrared spectroscopy were used to investigate the mechanism of FRNP formation. Efficient (∼500 times) improvement in photocurrent is observed in FRNP over PANI nanotubes on irradiation with white light. The photoresponse is quite reproducible even after several cycles with a time interval of 100s and in both the negative and positive bias photocurrent increases. A donor–acceptor based ‘electron–hole’ pair mechanism is proposed for the photocurrent behavior of FRNP. Using the PANI–a-RGO FRNP hybrid a dye sensitized solar cell with Rose Bengal dye is constructed yielding a power conversion efficiency of 2.012%.