Photocatalytic Phenol Degradation by Silica-Modified Titanium Dioxide

Diana Rakhmawaty Eddy,Soraya Nur Ishmah,Zeinhom M. El-Bahy,Iman Rahayu,Muhamad Diki Permana,Enas E. Hussein,M. Lutfi Firdaus,Yaser A. El-Badry

doi:10.3390/app11199033

Abstract

Titanium dioxide (TiO2) has been widely applied as a photocatalyst for wastewater treatment due to its high photocatalytic activity and it can remove various harmful organic pollutants effectively. Under heated system, however, TiO2 is prone to agglomeration that decrease its abilities as a photocatalyst. In order to overcome the agglomeration and increase its thermal resistance, addition of silica (SiO2) as supporting material is proposed in this research. Silica or silicon dioxide can be extracted from natural resources such as beach sand. Here, we report the application of a composite photocatalyst of TiO2/SiO2 to remove phenolic compounds in wastewater. The photocatalyst was synthesized by adding SiO2 from beach sand onto TiO2 through impregnation methods. The results of the X-ray diffraction (XRD) showed that TiO2 was present in the anatase phase. The highest crystallinity was obtained by TiO2/SiO2 ratios of 7:1. SEM results showed that the shape of the particles was spherical. Further characterizations were conducted using Fourier-transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET) analysis, and a particle size analyzer (PSA). By using the optimized condition, 96.05% phenol was degraded by the synthesized photocatalyst of TiO2/SiO2, under UV irradiation for 120 min. The efficiency of the TiO2/SiO2 is 3.5 times better than commercial TiO2 P25 for the Langmuir–Hinshelwood first-order kinetic model.

Highlights

Phenolic compounds and their derivatives have been used as raw materials in various manufacturing and petrochemical industries [1]
Like the majority of other organic substances used in industries, phenol is a carcinogenic compound that poses a high risk to human health and damages aquatic ecosystems, even at low concentrations [2]
A photocatalytic method was developed to serve as an alternative, using semiconductor materials with the potential for pollutant reduction

Summary

Introduction

Phenolic compounds and their derivatives have been used as raw materials in various manufacturing and petrochemical industries [1]. Like the majority of other organic substances used in industries, phenol is a carcinogenic compound that poses a high risk to human health and damages aquatic ecosystems, even at low concentrations [2]. Numerous techniques, including adsorption, precipitation, cross-flow microfiltration, electrodialysis, and reverse osmosis, have been used to actively investigate the removal of phenol from the environment. These methods are quite expensive and often inefficient at low concentrations. Semiconductor materials that have been used in photocatalysts for the degradation of organic pollutants in water include SnOx [6], ZnO [7], and TiO2 [4]

Methods

Results

Conclusion