Photocatalytic Degradation of Rhodamine B with H₃PW₁₂O₄₀/SiO₂Sensitized by H₂O₂

Abstract

In order to remove aquatic organic dye contaminants by utilizing the inexpensive and inexhaustible solar energy, the Keggin-type H3PW12O40was loaded on the surface of SiO2with the sol-gel method and sensitized by H2O2solution. The photocatalytic degradation of rhodamine B (RhB) by H3PW12O40/SiO2(x) under simulated natural light irradiation was investigated. The effects of the initial RhB concentration, the solution pH, and catalyst dosage on the photocatalytic degradation rate of RhB were also studied. The results demonstrated that at optimal condition (initial concentration of methyl orange is 10 mg/L, catalyst dosage is 0.8 g, and the pH is 2.5) the degradation rate of RhB is as high as 97.7% after 2 h under simulated natural light irradiation. The reaction of photocatalysis for RhB can be expressed as a first-order kinetic model.

An overview report on the application of heteropoly acids on supporting materials in the photocatalytic degradation of organic pollutants from aqueous solutions

“…Some studies indicated that an increase in photocatalyst dosage could result in increasing the photocatalytic efficiency (Yang et al, 2012). Therefore, an increase in the photocatalyst dosage does not always lead to the enhancement of photocatalytic activity (Hua et al, 2014; Wang, Huang & Yang, 2010; Yang et al, 2012). An excessive dosage increase, however, may decrease the photocatalytic efficiency.…”

“…An excessive dosage increase, however, may decrease the photocatalytic efficiency. It seems that surplus photocatalyst results in scattering the photons in the solution and decreasing the photons that reach the surface of photocatalyst (Feng & Shang, 2012; Xu et al, 2012; Yang et al, 2012). Some other researchers reported the same results for various composites (Feng & Shang, 2012; Wei et al, 2012; Xu et al, 2012).…”

“…Several studies have shown that an increase in pollutant concentration leads to a decrease in photocatalytic efficiency through different ways (Feng & Shang, 2012; Lu et al, 2013; Mahmoodi et al, 2016; Niu & Hao, 2011; Norzaee et al, 2017; Xu et al, 2012; Yang et al., 2012). …”

“…Several common processes such as condensation, ultrafiltration, membrane separation, and adsorption are applied for removing the organic pollutants. However, these methods cannot completely degrade the pollutants into nontoxic substances; rather, they often are just responsible for transferring these substances to other phases (Yang et al, 2012). In this regard, photocatalytic degradation can be regarded as one of the promising technologies to solve this problem (Lu et al, 2013; Norzaee et al, 2017).…”

Metastable β‐Bi2O3 Nanoparticles with Potential for Photocatalytic Water Purification Using Visible Light Irradiation

“…[29] Furthermore, the photocatalytically active sites are blocked, which results in a reduction in the interaction of photons. [20, 30–31] By using the Langmuir–Hinshelwood kinetic model the reaction parameters were determined by Equation (2):[30, 32]…”