Oxide-Clay Mineral as Photoactive Material for Dye Discoloration

Maicon O Miranda,Edson C Silva-Filho,Francisco Franco,Josy A Osajima,Maria Gardênnia Fonseca,Pollyana Trigueiro,Bartolomeu Cruz Viana,Luzia Maria Honório

doi:10.3390/min10020132

Maicon O Miranda, Edson C Silva-Filho + Show 6 more

Open Access

https://doi.org/10.3390/min10020132

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Abstract

Titanium and zirconium oxides (TiO2 and ZrO2, respectively) were obtained from alkoxides hydrolyses, and then deposited into palygorskite clay mineral (Pal) to obtain new materials for photocatalytic applications. The obtained materials were characterized by structural, morphological, and textural techniques. X-ray diffraction (XRD) results confirmed the characteristic peaks of oxides and clay transmission electron microscopy (TEM) and scanning electron microscopy (SEM) images of the modified palygorskite with both oxides showed that the clay was successfully modified by the proposed method. The increase in the specific surface area of the clay occurred when TiO2 and ZrO2 were deposited on the surface. The photocatalytic activity of these materials was investigated using the Remazol Blue anion dye under UV light. The evaluated systems presented high photocatalytic activity, reaching approximately 98% of dye discoloration under light. Thus, TiO2–Pal and ZrO2–TiO2–Pal are promising clay mineral-based photocatalysts.

Highlights

The substantial use of chemical compounds is essential to achieve the social and economic goals of the global community, and current best practices demonstrate that they can be widely used in a cost-effective manner and with a high degree of safety
Palygorskite was modified with nanoparticle oxides to produce a clay-based catalyst
The results showed that TiO2 and ZrO2 were continuously coated onto the surface of the fibrous palygorskite, thereby improving the specific surface area and narrowing the pore distribution

Summary

Introduction

The substantial use of chemical compounds is essential to achieve the social and economic goals of the global community, and current best practices demonstrate that they can be widely used in a cost-effective manner and with a high degree of safety. Much remains to be done to ensure the environmentally friendly use of toxic chemicals within the principles of sustainable development and to improve the quality of life of humankind [1,2]. Researchers and government entities are exploring solutions to mitigate the large amount of pollutants released into the environment, including textile dyes, which, despite their toxicity, are still released into bodies of water without prior treatment [5,6]. Dyes can be removed from the environment through attainable, low-cost techniques; advanced oxidative processes (AOPs) deserve special attention among these techniques [7,8].

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