Ocean University of China

About: Ocean University of China is a education organization based out in Qingdao, China. It is known for research contribution in the topics: Population & Sea surface temperature. The organization has 27604 authors who have published 27886 publications receiving 440181 citations. The organization is also known as: Zhōngguó Hǎiyáng Dàxué & OUC.

Efficient dye-sensitized solar cells from polyaniline–single wall carbon nanotube complex counter electrodes

Abstract: Dye-sensitized solar cell (DSSC) is a promising solution to global energy and environmental problems because of its clean energy, low cost, high efficiency, good durability, and easy fabrication. However, the commercial application of DSSCs has been hindered by limited power conversion efficiency. With an aim of significantly enhancing the light-to-electric conversion efficiency, here we pioneer synthesizing polyaniline–single wall nanotube (PANi–SWCNT) complexes using a reflux technique which are employed as counter electrodes (CEs) for DSSCs. Owing to the facile charge transfer between PANi (N atoms) and SWNT (C atoms) by a covalent bond, electrical conduction, electrocatalysis, and therefore conversion efficiency have been markedly elevated in comparison with that of PANi-only CE. The DSSC employing PANi–4‰ SWCNT complex CE gives an impressive power conversion efficiency of 7.81%. The high conversion efficiency, facile charge-transfer in combination with simple preparation, relatively low cost and scalability demonstrates the potential use of PANi–SWCNT complex in robust DSSCs.

Reversible redox reaction on the oxygen-containing functional groups of an electrochemically modified graphite electrode for the pseudo-capacitance

Abstract: Reversible redox reactions on the oxygen-containing functional groups of an electrochemically modified graphite electrode (GE) by recurrent galvanic pulses in 2.3 M H2SO4 solution are investigated. The crystal morphology, surface composition and electrochemical performance of electrochemically modified GE are monitored by scanning electron microscopy, Raman spectroscopy, nitrogen adsorption, Fourier transform infrared spectroscopy, thermogravimetry, Boehm's titration, X-ray photoelectron spectroscopy, electrochemical impedance spectroscopy and cyclic voltammetry (CV) tests. After the electrochemical modification, the material shows a turbostratic structure with many small domains consisting of multi-layered graphene sheets in parallel, and presents a high specific capacitance of 179.7 F g−1, as well as a good stability after 10000 CV cycles. The high specific capacitance is mainly attributed to the continuous reversible redox reactions of the active groups among the hydroxyl (reduced state), carbonyl (half-oxidized state) and carboxyl (fully oxidized state) groups; a redox mechanism is obtained consequently. The amount of active groups on the modified GE surface is about 848–875 μmol g−1 by the Boehm titration. Their contribution to the pseudo-capacitance according to the redox mechanism is about 130–140 F g−1, which is consistent with the results of electrochemical measurements.