Biosynthesis, characterization and optimization of TiO2 nanoparticles by novel marine halophilic Halomonas sp. RAM2: application of natural dye-sensitized solar cells

Rasha A Metwally; Jehan El Nady; Shaker Ebrahim; Amany El Sikaily; Nermeen A El-Sersy; Soraya A Sabry; Hanan A Ghozlan

doi:10.1186/s12934-023-02093-3

Biosynthesis, characterization and optimization of TiO₂ nanoparticles by novel marine halophilic Halomonas sp. RAM2: application of natural dye-sensitized solar cells

Microb Cell Fact. 2023 Apr 21;22(1):78. doi: 10.1186/s12934-023-02093-3.

Authors

Rasha A Metwally¹, Jehan El Nady², Shaker Ebrahim³, Amany El Sikaily⁴, Nermeen A El-Sersy⁵, Soraya A Sabry⁶, Hanan A Ghozlan⁶

Affiliations

¹ Marine Microbiology Lab., National Institute of Oceanography and Fisheries, NIOF, Alexandria, Egypt. rashaabdou2012@hotmail.com.
² Electronic Materials Department, Advanced Technology and New Materials Research Institute, City of Scientific Research and Technological Applications (SRTA-City), New Borg El-Arab City, Alexandria, Egypt.
³ Department of Materials Science, Institute of Graduate Studies and Research, Alexandria University, Alexandria, Egypt.
⁴ Marine Pollution Lab., National Institute of Oceanography and Fisheries, NIOF, Alexandria, Egypt.
⁵ Marine Microbiology Lab., National Institute of Oceanography and Fisheries, NIOF, Alexandria, Egypt.
⁶ Botany & Microbiology Department, Faculty of Science, Alexandria University, Alexandria, Egypt.

Abstract

Background: Metal oxide nanoparticles (NPs) are becoming valuable due to their novel applications. The green synthesis of TiO₂ NPs is more popular as a flexible and eco-friendly method compared to traditional chemical synthesis methods. TiO₂ NPs are the most commonly used semiconductor in dye-sensitized solar cells (DSSCs).

Results: The biogenic TiO₂ NPs were produced extracellularly by the marine halophilic bacterium Halomonas sp. RAM2. Response surface methodology (RSM) was used to optimize the biosynthesis process, resulting in a starting TiO₂ concentration of 0.031 M and a pH of 5 for 92 min (⁓15 nm). TiO₂ NPs were well-characterized after the calcination process at different temperatures of 500, 600, 700 and 800 °C. Anatase TiO₂ NPs (calcined at 500 °C) with a smaller surface area and a wider bandgap were nominated for use in natural dye-sensitized solar cells (NDSSCs). The natural dye used as a photosensitizer is a mixture of three carotenoids extracted from the marine bacterium Kocuria sp. RAM1. NDSSCs were evaluated under standard illumination. After optimization of the counter electrode, NDSSC_Bio(10) (10 layers) demonstrated the highest photoelectric conversion efficiency (η) of 0.44%, which was almost as good as NDSSC_P25 (0.55%).

Conclusion: The obtained results confirmed the successful green synthesis of TiO₂ NPs and suggested a novel use in combination with bacterial carotenoids in DSSC fabrication, which represents an initial step for further efficiency enhancement studies.

Keywords: Bacterioruberins; Carotenoids; Dye-sensitized solar cells; Halomonas; Kocuria; Spirilloxanthin; TiO2 nanoparticles.

MeSH terms

Coloring Agents
Halomonas*
Metal Nanoparticles*
Solar Energy*
Titanium

Substances

titanium dioxide
Titanium
Coloring Agents