RSM-Based Preparation and Photoelectrocatalytic Performance Study of RGO/TiO2 NTs Photoelectrode

Jinlong Zuo,Zhi Xia,Siying Yuan,Shiyou Yu,Junsheng Li,Yiwen Li,Chong Tan,Shaodong Yang

doi:10.3390/pr9091492

Abstract

In this paper, reduced graphene oxide (RGO) was prepared by a modified Hummers method and chemical reduction method, and an RGO/TiO2 NTs (RGO/TiO2 nanotubes) photoelectrode was prepared by the electrochemical deposition method. The as-prepared RGO/TiO2 NTs were analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD), and their photocatalytic activities were investigated by measuring the degradation of methylene blue (MB) under simulated solar light irradiation. The SEM and XRD results indicated that the original tubular structure of TiO2-NTs was not changed after RGO modification. The surface of the TiO2 NTs photoelectrode was covered with a non-uniform, flake-shaped reduced graphene oxide film. The thickness of the RGO/TiO2 NTs was increased to about 22.60 nm. The impedance of the RGO/TiO2 NTs was smaller than that of the TiO2 NT photoelectrode. The optimal preparation conditions of RGO/TiO2 NT photoelectrodes were investigated by using a single factor method and response surface method. The best preparation conditions were as follows: deposition potential at 1.19 V, deposition time of 10.27 min, and deposition temperature at 24.94 °C.

Highlights

When the voltage was 1.2 V, the photoelectrode had the best degradation effect on methylene blue (MB), and the degradation rate reached 65.7%. This may be due to the high deposition potential and to a large amount of reduced graphene oxide (RGO) deposited on the surface of the nanotubes, which reduces the light absorption performance (Figure 1)
When the deposition potential is 1.2 V, the photoelectric catalytic degradation effect of RGO/TiO2 NTs photoelectrode on MB is studied under different times
The results provide a reference for th Through single factor experiments, the optimal preparation conditions for RGO/TiO2

Summary

Introduction

The discharge of a large amount of dye wastewater has caused a huge threat to the environment, due to the toxicity, mutagenicity and carcinogenicity of dyes [1,2]. Considering the renewable source of solar energy, research on photocatalysis has been rapidly expanding in recent years [11]. Hole pairs in photocatalysis, so it has been widely used in the removal of pollutants in wastewater in recent years [12,13]. H2 and O2 by the TiO2 photoelectrode under light conditions. It is slightly difficult to use sunlight as an external light source for catalytic titanium dioxide. This limitation can be overcome by changing the form of titanium dioxide or doping with other materials. TiO2 nanotubes have been proven to have great research potential in photoelectric decomposition, Academic Editor: Xiaopeng Li

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