Photocatalytic Degradation of Organic Pollutants by Using Nanocrystalline Boron‐doped TiO₂ Catalysts

Abstract

In this work, bare or mixed environmentally non-benign organic pollutants have been decontaminated using borondoped TiO 2 nanoparticles (B@TiO 2 ). B@TiO 2 nanoparticles (NPs) with varying content of boron (0.0 to 7.0 mol %) are synthesized using sol-gel method. These NPs are characterized by using different tools. XRD reveals the high crystalline nature with formation of anatase phase and also shows slight increase in crystallite size with increase in boron content in TiO 2 host lattice. The optical shift towards higher wavelength increases with increase of boron doping and hence corresponding decrease in optical band gap of doped NPs is confirmed. FTIR and TGA studies reveal the increase of surface hydroxylation of NPs with increase in dopant content. B@TiO 2 samples have been used for the photocatalytic degradation of bisphenol A, rhodamine B, methylene blue, methyl orange and mixture of these three dyes under sunlight illumination. 7.0 mol % B@TiO 2 has shown the best activity than other prepared samples. Rate of degradation of mixed dyes using 7.0 mol % B@TiO 2 is about seven times higher to that of bare TiO 2 and also shown higher rate than other doped samples.

Preparation of High-Porosity B-TiO2/C3N4 Composite Materials: Adsorption–Degradation Capacity and Photo-Regeneration Properties

“…This result was caused by B element entering into the TiO 2 lattice and g-C 3 N 4 structure. According to the low electronegativity of B element, it can be inferred that the 2p orbital of B may be different from the 2p orbital of O. Hybridization was generated, thus, enabling enhanced visible light absorption [ 40 ]. Otherwise, the 650 °C and 750 °C had high light absorption capacity in the ultraviolet regions of 200–350 nm and 200–400 nm, respectively.…”

Comparative Photocatalytic Activity and Total Organic Carbon Removal Efficiency of TiO2 And ZnO for Reactive Black 5 Photodegradation

“…Metal oxide semiconductors such as TiO 2 , CdS, Fe 2 O 3 , SnO 2, and ZnO and their composites have been widely employed as catalysts in photodegradation processes [16–18] . TiO 2 and ZnO are the most widely utilized and investigated catalysts due to their excellent properties [19,20] . With a 3.2 eV band gap energy, TiO 2 has features that involve high photocatalytic activity, long‐term optical and chemical stability, and good compatibility with environmental and biological conditions [19,21] .…”

Improvement of photocatalytic activity in the degradation of 4-chlorophenol and phenol in aqueous medium using tin-modified TiO2 photocatalysts

“…One way to delay the recombination process of charge carriers for their application to degrade recalcitrant pollutants and in the generation of renewable energy sources is through various alternatives such as; doping with metals such as Sn, Fe, Zr, Mn, W and Mo, 13–17 non-metals such as S, Br, N, P, g-C 3 N 4 , etc. , 3,12,18,19 coupling with another semiconductor, semiconductor/non-metal or non-metal/non-metal with different morphology favoring type II heterojunctions, 7–10 generation of ternary hybrid materials between semiconductors and non-semiconductors 10,20,21 or simply by impregnating noble metal nanoparticles. 22…”

“…1,2 Some effects that stand out are the deterioration of the ozone layer, severe droughts, pollution of rivers and lakes, and the scarcity of drinking water, which is the product of demographic overexploitation and excessive use by different industries, such as the use of phenolic compounds for the manufacture of cosmetics and pharmaceutical products, paints, the textile industry, etc. 1,3 Additionally, the water used by these industries is discharged as effluent into different water currents. This is a dangerous practice that brings serious environmental contamination and severe damage to human health that ranges from simple headaches, to mutations, cancer, and even death from over exposure to them.…”