Hydrothermally derived Cr-doped SnO2 nanoflakes for enhanced photocatalytic and photoelectrochemical water oxidation performance under visible light irradiation

Ch Venkata Reddy; Raghava Reddy Kakarla; Jaesool Shim; Rustem R Zairov; Tejraj M Aminabhavi

doi:10.1016/j.envres.2022.114672

Hydrothermally derived Cr-doped SnO₂ nanoflakes for enhanced photocatalytic and photoelectrochemical water oxidation performance under visible light irradiation

Environ Res. 2023 Jan 15:217:114672. doi: 10.1016/j.envres.2022.114672. Epub 2022 Nov 7.

Authors

Ch Venkata Reddy¹, Raghava Reddy Kakarla², Jaesool Shim¹, Rustem R Zairov³, Tejraj M Aminabhavi⁴

Affiliations

¹ School of Engineering, Yeungnam University, Gyeongsan, 712749, South Korea.
² School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, NSW, 2006, Australia.
³ Aleksander Butlerov Institute of Chemistry, Kazan Federal University, Kazan, 420008, 1/29 Lobachevskogo Str, Russian Federation.
⁴ School of Advanced Sciences, KLE Technological University, Hubballi, 580031, Karnataka, India; School of Engineering, UPES, Bidholi, Dehradun, 248 007, Uttarakhand, India. Electronic address: aminabhavit@gmail.com.

PMID: 36356664
DOI: 10.1016/j.envres.2022.114672

Abstract

Photocatalytic dye degradation is a method of environmental degradation that is commonly used to eliminate various pollutants produced by pharmaceutical and textile industries. Herein, pure and chromium (Cr)-doped SnO₂ nanoflakes were synthesized using a simple facile hydrothermal method and photocatalytic properties were studied under visible light illumination. In addition, photoelectrochemical (PEC) water oxidation properties were also studied using the prepared samples. Doping of transition metal ions introduces structural defects, which narrow the band gap of host sample, resulting in high catalytic activity. The synthesized doped SnO₂ displayed a rutile tetragonal crystal phase with a nanoflakes-like surface morphology having no other contaminations. The optical band gap of Cr-doped SnO₂ nanoflakes was significantly reduced (2.48 eV) over the pure sample (3.32 eV), due to successful incorporation of Cr ions into the host lattice. Furthermore, the dye removal efficiency of these nanoflakes was investigated for methyl orange (MO) and tetracycline (TC) organic contaminations. The Cr-doped SnO₂ nanoflakes exhibited superior photodegradation with 87.8% and 90.6% dye removal efficiency, within 90 min of light illumination. PEC water oxidation analysis showed that the doped photoelectrode achieved enhanced photocurrent density and showed a higher photocurrent density (1.08 mA cm^-2) over that of the undoped electrode (0.60 mA cm^-2). Electrochemical impedance spectroscopy (EIS) showed that doped electrodes exhibited lesser charge resistance than the pure electrode. The synthesized Cr-doped SnO₂ nanoflakes are suitable for water oxidation and photodegradation of organic pollutants. Thus, we strongly believe that the obtained results in this report will continue to provide new opportunities for the improvement of effective visible light photocatalysts for industrial wastewater treatment and water splitting for H₂ generation.

Keywords: Doping effect; Environmental remediation; Hazardous pollutants; Metal oxide nanostructures; Photocatalysis; Photoelectrochemistry; SnO(2).

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Chromium
Environmental Pollutants*
Light
Oxidation-Reduction
Water* / chemistry

Substances

Water
Chromium
Environmental Pollutants