This study aimed to assess the optimal conditions for the extraction of chlorophyll and the stability of chlorophyll with postharvest storage period in Moringa Oleifera leaves harvested in 3 different years for its preservation and lifespan. For this purpose, chlorophylls a (Chla) and b (Chlb) were extracted from the leaves using acetone, methanol, N, N-dimethylformamide (DMF), and the ‘green’ solvent (ethanol). In addition, the chlorophylls were extracted under various conditions, including temperatures (4, 25, and 45 °C), and times (10, 30, and 60 min) from dry leaves that were harvested in different years (2020, 2021, and 2022). The results showed that the Chla content extracted exceeded that of Chlb in the four solvents in all temperatures and extraction times, except for acetone and ethanol extracts under 45 °C at 30 and 60-min extraction times in samples harvested in 2022. An increase in extraction time and temperature resulted in higher chlorophyll content. Overall chlorophyll content decreased with the increasing postharvest storage period, particularly in methanol and ethanol extracts. The Chlorophyll Stability Index showed that chlorophyll is stable in moringa, such that the chlorophyll content obtained in a 2-year postharvest storage period samples was also found to be high. In general, the chlorophyll obtained from this study was found to be compatible with what is used in the industrial market. This suggests that the chlorophyll from moringa is stable and can be considered a major source of chlorophyll.

Chlorophyll, a natural photosynthetic pigment, is gaining interest for its sustainable and eco-friendly applications in renewable energy, particularly as a photosensitizer in dye-sensitized solar cells (DSSCs). This study investigates the feasibility of chlorophyll extracted from Moringa oleifera as a natural photosensitizer in DSSCs, building on our previous work demonstrating its high chlorophyll content and long-term stability. Chlorophyll was extracted using acetone under optimal conditions (45 °C, 60 min) and applied in DSSCs comprising a TiO₂ photoanode, iodide/triiodide electrolyte, and platinum counter electrode. The TiO₂ photoanode was characterised using UV-Vis spectroscopy, FE-SEM, XRD, and Raman spectroscopy, confirming the presence of pure anatase phase TiO₂ with uniform spherical nanoparticle morphology. The fabricated DSSCs achieved a short-circuit current density of 0.197 mA cm⁻², an open-circuit voltage of 0.44 V, a fill factor of 32%, and a photoconversion efficiency (PCE) of 0.027%. While this performance is lower than the highest reported chlorophyll-based DSSC efficiency (4.6%), the results demonstrate that M. oleifera is a viable and sustainable source of chlorophyll for DSSC applications. The findings highlight the importance of dye–semiconductor interactions and suggest that further optimisation through co-sensitization, TiO₂ surface modification, and improved dye anchoring could enhance device performance.