$SnS_2$-$TiO_2$ heterojunction designed for reductive degradation of contaminants of emerging concern

Pandey, Suresh Kumar (author), Romac, Sandra (author), Papac Zjačić, Josipa (author), Kraljić Roković, Marijana (author), Kovačić, Marin (author), Kušić, Hrvoje (author), Žener, Boštjan (author), Genorio, Boštjan (author), Lavrenčič Štangar, Urška (author), Lončarić Božić, Ana (author)

Contaminants of emerging concern (CECs), including pharmaceuticals and perfluorinated compounds, pose a growing threat to water quality due to their persistence and resistance to conventional treatment methods. In this context, photocatalytic processes capable of promoting both oxidative and reductive transformations have attracted increasing attention. This study explores the synthesis and performance of a SnS$_2$-TiO$_2$ heterojunction photocatalyst, designed to facilitate such reactions under solar and UV-A light. The composite was synthesized via the hydrothermal method and thoroughly characterized for its morphological, structural, surface, and semiconducting properties. The results confirmed the formation of a type-II heterojunction with improved visible-light absorption and suppressed charge recombination. Photoelectrochemical measurements indicated enhanced charge separation and favorable band-edge alignment for reductive processes. Photocatalytic experiments with amoxicillin (AMX) and perfluorooctanoic acid (PFOA) revealed distinct degradation behaviors: AMX was predominantly degraded via superoxide-mediated reductive pathways, whereas PFOA exhibited limited transformation, likely proceeding via a combination of oxidative and reductive mechanisms. While overall removal efficiencies were moderate, this study highlights the role of band structure engineering and heterojunction design in tailoring photocatalytic behavior. The SnS$_2$-TiO$_2$ system serves as a promising platform for further development of composite materials to address the challenge of CECs in water treatment.

• Language: English
• Keywords: composites, solar photocatalysis, contaminants of emerging concern, reductive degradation
• 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: 2025
• Number of pages: 17 str.
• Numbering: Vol. 15, iss. 13, art. 969
• PID: 20.500.12556/RUL-173641
• UDC: 620.1:544.526.5
• ISSN on article: 2079-4991
• DOI: 10.3390/nano15130969
• COBISS.SI-ID: 240836611
• Publication date in RUL: 19.09.2025

Record is a part of a journal

• Title: Nanomaterials
• Shortened title: Nanomaterials
• Publisher: MDPI AG
• ISSN: 2079-4991
• COBISS.SI-ID: 523286297

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.

Secondary language

• Language: Slovenian
• Keywords: kompoziti, fotokataliza, onesnaževala v nastajanju, reduktivna razgradnja