AUTHOR=Qiu Xiaojian , Wan Zhenning , Pu Mengjie , Xu Xiuru , Ye Yuanyao , Hu Chunhua 

TITLE=Synthesis and Photocatalytic Activity of Pt-Deposited TiO2 Nanotubes (TNT) for Rhodamine B Degradation

JOURNAL=Frontiers in Chemistry

VOLUME=10

YEAR=2022

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2022.922701

DOI=10.3389/fchem.2022.922701

ISSN=2296-2646

ABSTRACT=<p>Dye wastewater has attracted more and more attention because of its high environmental risk. In this study, a novel TiO<sub>2</sub> nanotube (TNT) catalyst was prepared and its morphology and structure were characterized. The synthetic catalyst was used to degrade Rhodamine B (RhB) under UV light and evaluated for the application performance. According to the characterization results and degradation properties, the optimum synthetic conditions were selected as 400°C calcination temperature and 10 wt% Pt deposition. As a result, the degradation efficacies were sequenced as TNT-400-Pt &gt; TNT-500-Pt &gt; TNT-400 &gt; TNT-300-Pt. In addition, the effect of pH and initial concentration of RhB were explored, and their values were both increased with the decreased degradation efficacy. While the moderate volume of 11 mm of H<sub>2</sub>O<sub>2</sub> addition owned better performance than that of 0, 6, and 15 mm. Scavengers such as tertbutanol (<italic>t</italic>-BuOH), disodium ethylenediaminetetraacetate (EDTA-Na<sub>2</sub>), and nitroblue tetrazolium (NBT) were added during the catalytic process and it proved that superoxide radical anions <inline-formula id="inf1"><mml:math id="m1" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mrow><mml:mo>(</mml:mo><mml:mrow><mml:msubsup><mml:mi>O</mml:mi><mml:mn>2</mml:mn><mml:mrow><mml:mo>–</mml:mo><mml:mo>•</mml:mo></mml:mrow></mml:msubsup></mml:mrow><mml:mo>)</mml:mo></mml:mrow></mml:mrow></mml:math></inline-formula>, photogenerated hole (h<sup>+</sup>) and hydroxyl radical (OH•) were the main active species contributing for RhB removal. For the application, TNT-Pt could deal with almost 100% RhB, Orange G (OG), Methylene blue (MB), and Congo red (CR) within 70 min and still kept more than 50% RhB removal in the fifth recycling use. Therefore, TNT-Pt synthesized in this study is potential to be applied to the dye wastewater treatment.</p>