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

Tariq Shah,Khalid Saeed,Tamanna Gul

doi:10.1007/s13201-019-0983-z

Tariq Shah, Khalid Saeed + Show 1 more

Open Access

https://doi.org/10.1007/s13201-019-0983-z

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Abstract

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.

Highlights

The effluents were released from food processing, leather, paper, textile and dyes manufacturing industries containing various types of coloring materials, which generate nonaesthetic pollution and eutrophication
The increase in photodegradation of dye with increase in catalyst amount might be due to the increase in active sites, which results to increase the number of hydroxyl and superoxide radicals as a result, dye degrades significantly
It is concluded that the morphological study showed that the TiO2 particles were dispersed well on the surface of GNP

Summary

Introduction

The effluents were released from food processing, leather, paper, textile and dyes manufacturing industries containing various types of coloring materials, which generate nonaesthetic pollution and eutrophication. The majority of dyes is toxic and carcinogenic, non-biodegradable (large size and complex structures) and may contribute to the formation of dangerous by-products through the chemical reactions that take place in the wastewater bodies (oxidation, hydrolysis, etc.) (Ramírez et al 2012) These coloring materials can be removed from the industrial effluents by using various chemical and physical techniques such as advance oxidation process, adsorption and coagulation, reverse osmosis and ultrafiltration (Ladakowicz et al 2001; Lee et al 2006; Nataraj et al 2009; Zhao et al 2012). The. Applied Water Science (2019) 9:105 bromophenol blue was selected because it is commonly used as a pH indicator and as a dye. Dried graphene nanoplates-supported titanium oxide ( TiO2/ GNP) sample was stored for further use. The photodegradation study of bromophenol blue was performed using UV–visible spectrophotometer (UV-1800, Shimadzu, Japan)

Result and discussion

Findings

Conclusion

Compliance with ethical standards