Room temperature bio-engineered multifunctional carbonates for CO2 sequestration and valorization

H Mohamed; K Hkiri; N Botha; K Cloete; Sh Azizi; A A Q Ahmed; R Morad; Th Motlamane; A Krief; A Gibaud; M Henini; M Chaker; I Ahmad; M Maaza

doi:10.1038/s41598-023-42905-5

Room temperature bio-engineered multifunctional carbonates for CO₂ sequestration and valorization

Sci Rep. 2023 Oct 5;13(1):16783. doi: 10.1038/s41598-023-42905-5.

Authors

H Mohamed^{1

2

3}, K Hkiri^{1

2}, N Botha^{1

2}, K Cloete^{1

2}, Sh Azizi^{1

2}, A A Q Ahmed^{1

2}, R Morad^{1

2}, Th Motlamane^{1

2}, A Krief^{1

2

4}, A Gibaud^{1

2

5}, M Henini^{1

2

6}, M Chaker^{1

2

7}, I Ahmad^{1

2

8}, M Maaza^{9

10}

Affiliations

¹ UNESCO-UNISA Africa Chair in Nanosciences-Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria, South Africa.
² Nanosciences African Network (NANOAFNET), Materials Research Department, iThemba LABS-National Research Foundation of South Africa, 1 Old Faure Road, Somerset West, PO Box 722, Cape Town, 7129, Western Cape, South Africa.
³ College of Graduate Studies, University of South Africa, PRETORIA, South Africa.
⁴ Chemistry Department (CMI Laboratory), University of Namur, 2 Rue Joseph Grafé, 5000, Namur, Belgium.
⁵ IMMM, UMR 6283 CNRS, University of Le Maine, Bd O. Messiaen, 72085, Le Mans Cedex 09, France.
⁶ Physics and Astronomy Department, Nottingham University, Nottingham, NG7 2RD7, UK.
⁷ INRS-Energie et Matériaux, 1650 Lionel-Boulet, Varennes, QC, J3X 1S2, Canada.
⁸ Experimental Physics Directorate (EPD), National Center for Physics, Islamabad, 44000, Pakistan.
⁹ UNESCO-UNISA Africa Chair in Nanosciences-Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria, South Africa. Maaza@tlabs.ac.za.
¹⁰ Nanosciences African Network (NANOAFNET), Materials Research Department, iThemba LABS-National Research Foundation of South Africa, 1 Old Faure Road, Somerset West, PO Box 722, Cape Town, 7129, Western Cape, South Africa. Maaza@tlabs.ac.za.

Abstract

This contribution reports, for the first time, on an entirely green bio-engineering approach for the biosynthesis of single phase crystalline 1-D nano-scaled calcite CaCO₃. This was validated using H₂O as the universal solvent and natural extract of Hyphaene thebaica fruit as an effective chelating agent. In this room temperature green process, CaCl₂ and CO₂ are used as the unique source of Ca and CO₃ respectively in view of forming nano-scaled CaCO₃ with a significant shape anisotropy and an elevated surface to volume ratio. In terms of novelty, and relatively to the reported scientific and patented literature in relation to the fabrication of CaCO₃ by green nano-chemistry, the current cost effective room temperature green process can be singled out as per the following specificities: only water as universal solvent is used, No additional base or acid chemicals for pH control, No additional catalyst, No critical or supercritical CO₂ usage conditions, Only natural extract of thebaica as a green effective chelating agent through its phytochemicals and proper enzematic compounds, room Temperature processing, atmospheric pressure processing, Nanoscaled size particles, and Nanoparticles with a significant shape anisotropy (1-D like nanoparticles). Beyond and in addition to the validation of the 1-D synthesis aspect, the bio-engineered CaCO₃ exhibited a wide-ranging functionalities in terms of highly reflecting pigment, an effective nanofertilizer as well as a potential binder in cement industry.

Grants and funding

U2ACN2-2023/University of South Africa