Photodegradation of bromophenol blue in aqueous medium using graphene nanoplates-supported TiO₂

The bromophenol blue dye in aqueous medium was photodegraded (under UV irradiation) by graphene nanoplates-supported titanium oxide (TiO₂/GNP). The determination of various elements (percentage) and morphological study was performed using energy-dispersive X-rays and scanning electron microscopy, while the photodegradation study of dye was done by UV–visible spectrophotometer. The morphological study showed that the TiO₂ particles were dispersed well on the surface of GNP. The sizes of TiO₂ particles were below 500 nm. The photodegradation study was performed as function of time, and it was found that the photodegradation of dye in aqueous medium was increased as the time duration of UV irradiation increased. It was found that about 86% of dye was degraded within 8 h. The degradation of bromophenol blue is pH-dependent, and the photodegradation rate was increased as the pH of solution increased. The increase in dye degradation might be due to the formation of more hydroxyl radical at higher pH. The degradation of dye at pH 2, 4, 6 and 8 was about 70, 79, 90 and 95%, respectively.