Facile Synthesis of SrCO₃-Sr(OH)₂/PPy Nanocomposite with Enhanced Photocatalytic Activity under Visible Light.

Victor Ovando-Medina,Alfredo Márquez-Herrera,Miguel Meléndez-Lira,Blanca Castillo-Reyes,Jaquelina González-Castañeda,Martin Zapata-Torres

doi:10.3390/ma9010030

Abstract

Pyrrole monomer was chemically polymerized onto SrCO3-Sr(OH)2 powders to obtain SrCO3-Sr(OH)2/polypyrrole nanocomposite to be used as a candidate for photocatalytic degradation of methylene blue dye (MB). The material was characterized by Fourier transform infrared (FTIR) spectroscopy, UV/Vis spectroscopy, and X-ray diffraction (XRD). It was observed from transmission electronic microscopy (TEM) analysis that the reported synthesis route allows the production of SrCO3-Sr(OH)2 nanoparticles with particle size below 100 nm which were embedded within a semiconducting polypyrrole matrix (PPy). The SrCO3-Sr(OH)2 and SrCO3-Sr(OH)2/PPy nanocomposites were tested in the photodegradation of MB dye under visible light irradiation. Also, the effects of MB dye initial concentration and the catalyst load on photodegradation efficiency were studied and discussed. Under the same conditions, the efficiency of photodegradation of MB employing the SrCO3-Sr(OH)2/PPy nanocomposite increases as compared with that obtained employing the SrCO3-Sr(OH)2 nanocomposite.

Highlights

The first step implies the production of Sr(OH)2 powders as a water insoluble white dust, which precipitates from the reaction medium according to the double-displacement chemical reaction in which the hydrated form of Sr(OH)2 can be formed
Since a practical point of view, the SrCO3 -Sr(OH)2 /polypyrrole matrix (PPy) nanocomposite can be removed from methylene blue dye (MB) aqueous solutions due to its water insolubility, facilitating its recovery
MB degradation, and show the enhanced performance of the SrCO3 -Sr(OH)2 /PPy nanocomposite nanocomposite under the studied conditions. These results show that based efficiency of MB degradation, and show the enhanced performance of the SrCO3‐Sr(OH)2/PPy under the studied conditions

Summary

Introduction

Photocatalytic degradation has proven to be a promising technology for the removal of various organic pollutants in waste water because of its many attractive advantages, including its environmental friendly feature, relatively low cost, and low energy consumption [1,2,3,4,5,6,7,8,9,10].Photocatalytic processes are methods that utilize the solar radiation energy to perform catalytic processes such as water splitting, waste mineralization, recovery of precious metals, etc. [11,12].Many photocatalytic materials have wide bad-gap values and require ultraviolet light (UV) to be photoactive. The need of UV light for activating the photocatalyst greatly limits practical applications because of the low content of UV light in the solar spectrum (about 4%) [13]. Materials 2016, 9, 30 to take complete advantage of the sunlight one needs to make a visible light activated photocatalyst or increase its efficiency in the UV light region. It has been reported that by using composite films or powders consisting of two semiconducting photocatalysts the absorption edge is shifted to the visible light region, e.g., TiO2 -SrTiO3 ́δ [22], BiVO4 -SrTiO3 :Rh [23], Ag3 PO4 -Cr-SrTiO3 [24], Fe2 O3 -SrTiO3 [25], SrCO3 -SrTiO3 [26], TiO2 -SO4 [27], g-C3 N4 /Fe3 O4 /Ag3 VO4 [28]. The inset shows the spectrum of Sr. 5/2 and Sr 3d3/2 for the SrCO3 -Sr(HO) sample. The inset shows the deconvolution of the Sr 3d5/2 signal.

Methods

Results

Conclusion