Vacuum-assisted impregnation derived a-Bi<inf>2</inf>O<inf>3</inf>/TiO<inf>2</inf> nanotube arrays with enhanced photoelectrochemical activity

Abstract

© 2015 Elsevier B.V. With the aim of improving the performance of TiO<inf>2</inf> nanotube arrays (NTAs), a-Bi<inf>2</inf>O<inf>3</inf> nanoparticles were successfully implanted into the nanotube arrays via a vacuum-assisted impregnation strategy for the first time. Photoelectrochemical characterizations and comparative investigations on the degradation efficiency of 2-Chlorophenol demonstrate the enhanced photo activity of a-Bi<inf>2</inf>O<inf>3</inf>/TiO<inf>2</inf> nanotube arrays over the pure nanotube arrays. The as-prepared a-Bi<inf>2</inf>O<inf>3</inf>/TiO<inf>2</inf>-NTAs grown on Ti behaved as a recyclable and stable electrode and outperformed pure TiO<inf>2</inf>-NTAs. The a-Bi<inf>2</inf>O<inf>3</inf> nanoparticles modified TiO<inf>2</inf> nanotube arrays could favor the separation and transfer of photoinduced charge carriers, which promote the energy conversion and the generation of reactive radicals upon irradiation. The predominant superoxide radicals were evidenced by electron spin resonance signals.