One-pot synthesis of sulfur-doped TiO$_2$/reduced graphene oxide composite (S-TiO$_2$/rGO) with improved photocatalytic activity for the removal of diclofenac from water

Kovačić, Marin (author), Perović, Klara (author), Papac, Josipa (author), Tomić, Antonija (author), Matoh, Lev (author), Žener, Boštjan (author), Brodar, Tomislav (author), Capan, Ivana (author), Surca, Angelja Kjara (author), Kušić, Hrvoje (author), Lavrenčič Štangar, Urška (author), Lončarić Božić, Ana (author)

Sulfur-doped TiO$_2$ (S-TiO$_2$) composites with reduced graphene oxide (rGO), wt. % of rGO equal to 0.5%, 2.75%, and 5.0%, were prepared by a one-pot solvothermal procedure. The aim was to improve photocatalytic performance in comparison to TiO$_2$ under simulated solar irradiation for the treatment of diclofenac (DCF) in aqueous medium. The obtained composites were characterized for physical-chemical properties using thermogravimetric analysis (TGA), X-ray diffractograms (XRD), Raman, scanning electron microscopy (SEM)/energy dispersive X-ray (EDX), Brauner Emmett Teller (BET), and photoluminescence (PL) analyses, indicating successful sulfur doping and inclusion of rGO. Sulfur doping and rGO have successfully led to a decrease in photogenerated charge recombination. However, both antagonistic and synergistic effects toward DCF treatment were observed, with the latter being brought forward by higher wt.% rGO. The composite with 5.0 wt.% rGO has shown the highest DCF conversion at pH 4 compared to that obtained by pristine TiO$_2$, despite lower DCF adsorption during the initial dark period. The expected positive effects of both sulfur doping and rGO on charge recombination were found to be limited because of the subpar interphase contact with the composite and incomplete reduction of the GO precursor. Consequent unfavorable interactions between rGO and DCF negatively influenced the activity of the studied S-TiO$_2$/rGO photocatalyst under simulated solar irradiation.

• Language: English
• Keywords: photocatalysis, sulfur doped titanium dioxide, composite, reduced graphene oxide, diclofenac, solar photocatalysis, TiO$_2$-reduced graphene oxide composite
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Publication status: Published
• Publication version: Version of Record
• Year: 2020
• Number of pages: 14 str.
• Numbering: Vol. 13, iss. 7, art. 1621
• PID: 20.500.12556/RUL-133389
• UDC: 620:549.514.6:544.526.5
• ISSN on article: 1996-1944
• DOI: 10.3390/ma13071621
• COBISS.SI-ID: 1538563267
• Publication date in RUL: 25.11.2021

Record is a part of a journal

• Title: Materials
• Shortened title: Materials
• Publisher: MDPI
• ISSN: 1996-1944
• COBISS.SI-ID: 33588485

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.
• Licensing start date: 01.04.2020

Secondary language

• Language: Slovenian
• Keywords: fotokataliza, titanov dioksid dopiran z žveplom, kompoziti, reduciran grafen oksid, diklofenak