G–C3N4– and polyaniline-co-modified TiO2 nanotube arrays for significantly enhanced photocatalytic degradation of tetrabromobisphenol A under visible light

Abstract

An ordered g–C3N4– and polyaniline-modified titanium oxide nanotube array (g–C3N4– and PANI-co-modified TiO2 NTAs) was successfully synthesized and used as a photocatalyst. Polyaniline (PANI) was coated onto TiO2 NTAs by electrochemical polycondensation, and g-C3N4 was deposited via the soaking adsorption method. The photocatalysts were examined by several technologies. The experiments demonstrated that the amount of g-C3N4 and PANI, as well as the initial pH value, had significant effects on the photocatalytic efficiency. The resulting photocatalysts exhibited high visible light photocatalytic ability for tetrabromobisphenol A (TBBPA) for two reasons. First, PANI expanded the light absorption into the visible region. Second, rapid and efficient separation of photoinduced charges from the photogenerated potential difference were produced at the contact interface of g-C3N4 and PANI-co-modified TiO2 NTAs. The •OH, •O2− and h+ were dominant components for the photocatalytic degradation of TBBPA. In addition, the g-C3N4 and PANI-co-modified TiO2 NTAs have excellent long-term stability.