Photocatalytic Degradation of Organic Dye by Sol‐Gel‐Derived Gallium‐Doped Anatase Titanium Oxide Nanoparticles for Environmental Remediation

Abstract

Photocatalytic degradation of toxic organic chemicals is considered to be the most efficient green method for surface water treatment. We have reported the sol-gel synthesis of Gadoped anatase TiO2nanoparticles and the photocatalytic oxidation of organic dye into nontoxic inorganic products under UV irradiation. Photodegradation experiments show very good photocatalytic activity of Ga-doped TiO2nanoparticles with almost 90% degradation efficiency within 3 hrs of UV irradiation, which is faster than the undoped samples. Doping levels created within the bandgap of TiO2act as trapping centers to suppress the photogenerated electron-hole recombination for proper and timely utilization of charge carriers for the generation of strong oxidizing radicals to degrade the organic dye. Photocatalytic degradation is found to follow the pseudo-first-order kinetics with the apparent 1st-order rate constant around1.3×10−2 min-1. The cost-effective, sol-gel-derived TiO2 : Ga nanoparticles can be used efficiently for light-assisted oxidation of toxic organic molecules in the surface water for environmental remediation.

Recent developments in TiO2 as n- and p-type transparent semiconductors: synthesis, modification, properties, and energy-related applications

“…TiO 2 is a versatile material that has been used in many applications, such as gas sensors, solar cells, photocatalytic layers for self-cleaning glass, photocatalytic degradation of organic wastes, hydrogen production, storage media, optical coatings for filters and waveguides, and various biological-and health-related applications [47][48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64][65][66]. Since the early twentieth century, titanium dioxide (TiO 2 ) has been widely used as a pigment in sunscreens, paints, ointments, toothpaste, etc.…”

Improvement of Orange II Photobleaching by Moderate Ga3+ Doping of Titania and Detrimental Effect of Structural Disorder on Ga Overloading

“…The specific vibration modes are located at 148 cm −1 (Eg), 399 cm −1 (B1 g), 512 cm −1 (B1g + A1g), and 630 cm −1 (Eg), indicating the presence of the anatase phase in all of these samples. The absence of Raman active band around 318 cm −1 , which would be characteristic for Ga 2 O 3 [9], shows the absence of crystalline gallium oxide. Unfortunately, neither Raman spectroscopy is sufficiently sensitive to amorphous (or highly defective) phases.…”

“…Banerjee et al [9] reported on the oxidation of organic dye (Rhodamine B) into nontoxic inorganic products under UV irradiation using a Ga-doped TiO 2 synthesised by solgel technique. Pure TiO 2 , single-doped, and Ga+N codoped titania nanoparticles were successfully prepared by sol-gel method.…”

Gallium and indium nanomaterials for environmental protection

“…Titanium dioxide (TiO 2 ) NPs in anatase form are often used as photocatalyts. Anatase NPs doping with Ga by applying sol-gel method is reported [36]. The NPs obtained (with size of around 15 nm) were used to study the photocatalytic degradation of organic dye solution (Rhodamine B) as a model pollutant under UV irradiation.…”