High efficiency photocatalytic degradation of Ambroxol over Mn doped TiO2: Experimental designs, identification of transformation products, mineralization and mechanism

Abstract

Ambroxol (AMB) is a drug commonly used for chronic bronchitis prevention. Once released in surface water, this recalcitrant chemical becomes a hazardous pollutant.Here, we investigated the ability of 1% Mn-doped TiO 2 (Mn-TiO 2 ) to mineralize AMB by photocatalysis. We studied the morphology, and the physical and electrochemical properties of Mn-TiO 2 using X-ray diffraction, Scanning electron microscopy, Transmission electron microscopy, X-ray fluorescence, BET method, UV-visible, and electrochemical study and optimized the AMB degrading experimental conditions through response surface methodology (RSM). Mn-TiO 2 at the dose of 0.625 g.L -1 allowed the complete photodegradation of AMB (30 ppm) at pH 7 under UVA light irradiation for 30 min while total mineralization in CO 2 (> 96%) was achieved after 24 h of irradiation. Mn-TiO 2 was 1.6-time more efficient than TiO 2 Degussa P25. Product studies were also carried out by liquid 2 chromatography coupled to electrospray high resolution mass spectrometry. Twentyone photodegradation products were detected and identified. In addition, ionic chromatography analyses revealed the release of Br -, NH 4 + , and NO 3 at respectively 97, 63 and 35% of the total Br, and N initially present in AMB. Finally, the reusability of the photocatalyst was also tested. After four cycles, the almost complete photodegradation of AMB was achieved showing that Mn-TiO 2 was highly stable.This work brings new physical characteristics on Mn-TiO 2 photocatalyst. Moreover, it is the first study investigating the photocatalytic degradation of recalcitrant AMB drug.

Synthesis and Characterization of Manganese-Modified Black TiO2 Nanoparticles and Their Performance Evaluation for the Photodegradation of Phenolic Compounds from Wastewater

“…Consequently, Mn(III) can trap both h+ and electrons to assist the charge transfer process in TiO 2 . Mn(IV) is formed via the oxidation of Mn(III) by h+ through a valence band process, and then free hydroxyl OH − is quickly adsorbed and reacts with unstable Mn(III) to produce adsorbed radicals [ 63 ].…”

Nanomaterials for Photocatalytic Degradations of Analgesic, Mucolytic and Anti-Biotic/Viral/Inflammatory Drugs Widely Used in Controlling SARS-CoV-2

“…This stubborn chemical becomes a dangerous contaminant if it is discharged into surface water. Tab et al [98] examined the capacity of 1% Mn-doped TiO 2 (Mn-TiO 2 (in both anatase and rutile phases)) to photocatalyze the mineralization of AMB. In the presence of UVA light, for 30 min, complete degradation of the AMB (30 ppm) was achieved using Mn-TiO 2 at a dosage of 0.625 g L −1 at pH 7, whereas complete mineralization in CO 2 (more than 96%) was obtained after 24 h. Mn-TiO 2 outperformed TiO 2 Degussa P25 by 1.6 times.…”

Sol–gel method synthesized Ce‐doped TiO2 visible light photocatalyst for degradation of organic pollutants

“…Therefore, a lot of study have been carried out on the degradation of dye using photocatalysts. [24][25][26][27][28][29][30][31][32][33][34][35][36][37][54][55][56][57] In this study, we have taken mixture of dyes as a representative of industrial effluent. To study the degradation of mixture of dyes, we have taken a 200 ml, 20 ppm solution of mixture of dyes, namely, brilliant green, methylene blue, and rhodamine B, and 100 mg of best working catalyst 5 mol% Ce-doped TiO 2 .…”

“…[23] Different metals such as V, Cr, Fe, Co, Mn, Mo, Ni, Cu, and Ce can be used for TiO 2 doping. [24][25][26][27][28][29][30][31][32] Further, for this purpose, different nonmetals can also be used as dopant, such as nitrogen, carbon, phosphorus, boron, and iodine. [33][34][35][36][37] For our study, we have selected ceria as a dopant.…”