Reduced Graphene Oxide–P25 Nanocomposites as Efficient Photocatalysts for Degradation of Bisphenol A in Water

Fei Yu,Jie Ma,Changfu Yang,Lijie Xu,Xueting Bai

doi:10.3390/catal9070607

Abstract

Reduced graphene oxide–titanium dioxide photocatalyst (rGO–TiO2) was successfully synthesized by the hydrothermal method. The rGO–TiO2 was used as photocatalyst for the degradation of bisphenol A (BPA), which is a typical endocrine disruptor of the environment. Characterization of photocatalysts and photocatalytic experiments under different conditions were performed for studying the structure and properties of photocatalysts. The characterization results showed that part of the anatase type TiO2 was converted into rutile type TiO2 after hydrothermal treatment and 1% rGO–P25 had the largest specific surface area (52.174 m2/g). Photocatalytic experiments indicated that 1% rGO–P25 had the best catalytic effect, and the most suitable concentration was 0.5 g/L. When the solution pH was 5.98, the catalyst was the most active. Under visible light, the three photocatalytic mechanisms were ranked as follows: O2•− > •OH > h+. 1% rGO–P25 also had strong photocatalytic activity in the photocatalytic degradation of BPA under sunlight irradiation. 1% rGO–P25 with 0.5 g/L may be a very promising photocatalyst with a variety of light sources, especially under sunlight for practical applications.

Highlights

As a typical endocrine disruptor of the environment, bisphenol A (BPA) causes harm to the environment and human health because of the increasing concentrations in the environment [1].it affects the physiological metabolism of higher animals [2]
The pure P25 with strong agglomeration becomes dispersed when the graphene is added, and the graphene sheet is interspersed between the P25 molecules, forming some reduced graphene oxide (rGO)–P25 platelets [12,39]. This structure can produce a good deal of surface defect sites, which are beneficial for improving photocatalytic performance [40]
RGO–P25 composite photocatalyst was synthesized by hydrothermal method

Summary

Introduction

As a typical endocrine disruptor of the environment, bisphenol A (BPA) causes harm to the environment and human health because of the increasing concentrations in the environment [1]. It affects the physiological metabolism of higher animals [2]. An advanced oxidation process (AOP), especially photocatalytic technology that uses semiconductor material as a catalyst, is widely applied in wastewater-treatment for BPA [3,4]. As currently known, when light irradiates the surface of TiO2 with higher photo-energy than the bandgap of TiO2 , photoelectrons, and photo-holes will be generated.

Methods

Results

Conclusion