Green synthesis of CuO nanoparticles from Cucurbita maxima leaf extract; a platinum free counter electrode for dye sensitized solar cells

Emma Panzi  Mukhokosi; Stephen  Tenywa; Nandipha L.  Bothab; Shohreh  Azizi; Mathapelo Pearl  Seopela; Malik  Maaza

doi:10.46481/jnsps.2025.2309

Authors

Emma Panzi Mukhokosi
[email protected]
Department of Physics, Faculty of Science, Kyambogo University, PO Box 1, Kampala, Uganda
Stephen Tenywa Department of Physics, Faculty of Science, Kyambogo University, PO Box 1, Kampala, Uganda
Nandipha L. Bothab College of Graduate Studies, UNESCO UNISA Africa Chair in Nanosciences & Nanotechnology, University of South Africa, Pretoria, South Africa Materials; Materials Research Department, Nanosciences African Network (NANOAFNET), iThemba LABS, PO Box 722, Cape Town, South Africa
Shohreh Azizi College of Graduate Studies, UNESCO UNISA Africa Chair in Nanosciences & Nanotechnology, University of South Africa, Pretoria, South Africa Materials; Research Department, Nanosciences African Network (NANOAFNET), iThemba LABS, PO Box 722, Cape Town, South Africa
Mathapelo Pearl Seopela Department of Chemical Sciences, University of South Africa, Auckland Park Campus, PO Box 524, Auckland Park, 2006, Johannesburg, South Africa
Malik Maaza College of Graduate Studies, UNESCO UNISA Africa Chair in Nanosciences & Nanotechnology, University of South Africa, Pretoria, South Africa; Materials Research Department, Nanosciences African Network (NANOAFNET), iThemba LABS, PO Box 722, Cape Town, South Africa

Keywords:

Green synthesis, DSSCs, CuO, Cucurbita maxima, Natural dye

Abstract

Green synthesis of metal oxides has attracted attention as the latest technology in synthesizing metal oxide nanoparticles due to its simplicity, cheapness, non-toxicity and its ability for large scale production. Metal oxides find applications in dye sensitized solar cells (DSSCs) as counter electrodes (CEs) and photo-anodes. However, applications of green synthesized metal oxides as counter electrodes have not been fully explored. In this study, CuO nanoparticles (NPs) were synthesized from Cucurbita maxima leaf extract and applied as a CE in DSSC. Uniformly synthesized CuO NPs were subjected to various characterization tools to obtain the crystal structure, surface morphology, particle size, optical properties, chemical bonds and photovoltaic properties. Using a natural dye from of Cucurbita maxima as a photon absorber, a short circuit current density ( J_sc) of 4.2 µA/cm², open circuit voltage (V_oc) of 0.17 V, a maximum power (P_max) of 0.18 mW/cm², and a power conversion efficiency (PCE) of 1.8 × 10^?4% under one-sun illumination were obtained.

Dimensions

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