Photogalvanic effect of natural photosensitizer (crude spinach extract) in artificial light for simultaneous solar power generation and storage

Abstract

The synthetic dyes as photo‐sensitizers have been extensively studied in the photogalvanic cells for solar energy conversion and storage in artificial light. To make photogalvanic cells more environmentally friendly and sustainable, the natural and renewable source like crude extract of the spinach has been studied as sensitizer material in this study. Remarkable steady state power and current generation with simultaneous power storage have been observed. The observed cell performance (charging time 18 min, Open‐circuit potential 1050 millivolt, Short‐circuit current 1750 micro ampere, power 384.0 micro watt, storage capacity as half change time 44 min, efficiency ≈ 9.22%) is very encouraging to photogalvanics. This study shows that the natural resources like crude spinach extract can also sensitize photogalvanics with efficiency as high as for synthetic dye sensitizers with additional advantage of low cost and free from pollution, which is associated with production and disposal of dyes. Natural resources like crude spinach extract‐based PG follow same principles as for synthetic dye sensitizers. © 2017 American Institute of Chemical Engineers Environ Prog, 37: 1800–1807, 2018

Use of Pigments Present in the Crude Aqueous Extract of the Spinach for the Simultaneous Solar Power and Storage at Natural Sun Intensity

“…The originality of the present manuscript especially with respect to earlier reported study [ 19 ] is justified as only some points. Every solar cell technique has to show its workability in natural sunlight.…”

“…In the present study, the cell performance is shown in natural sunlight conditions ultimately for daily life needs of the society. In the previous study, [ 19 ] the work was studied in laboratory conditions of artificial and low intensity.…”

“…This fact has been studied in the present work, but not in earlier work. [ 19 ] For a study at different illumination window sizes, each cell has used a natural sunlight intensity of 100 mW cm −2 , a diffusion length ( D L ) of 6.3 cm, a Pt electrode area (0.4 × 0.2 cm 2 ), 3.8 mL of crude spinach extract, 36 mL of NaOH (pH 13.72),16 mL of M/100 fructose (resultant concentration of 2.35 × 10 −3 M), and 10 mL of M/10 NaLS (resultant concentration of 1.47 × 10 −2 M). The cells were illuminated through the window sizes of 2.0 × 1.5 cm 2 (3.0 cm 2 ), 1.5 × 0.8 cm 2 (2.0 cm 2 ), 0.8 × 0.6 cm 2 (0.48 cm 2 ), 1.0 × 1.0 cm 2 (1.0 cm 2 ), and 0.4 × 0.2 cm 2 (0.08 cm 2 ), respectively ( Table 8 ).…”

“…The crude aqueous extract of the naturally occurring spinach resource‐sensitized PG cell has been studied at the artificial and low illumination intensity with impressive results (384.0 μW, 1750 μA, and 9.22%). [ 19 ] But, the reported spinach extract‐based cells have the drawback that its workability is shown at very low and artificial illumination intensity only, [ 19 ] whereas these cells have to be workable at natural sunlight intensity for day‐to‐day life applications. Natural sunlight‐irradiated Rhodamine B dye‐sensitized and surface‐active reagent augmented PG solar energy conversion (620.1 μW, 2400 μA, and 7.75%) and storage have been reported recently, [ 20 ] but the study on naturally illuminated natural sensitizer spinach extract‐based PG cells has not attracted attention of the researchers yet.…”

Potential of plant‐based photosensitizers in dye‐sensitized solar cell applications

“…Though the conversion efficiency was reported to exceed 11%, the ruthenium metal‐based photosensitizers were undesirable due to their toxicity, tricky synthetic procedures, rarity, environmental pollution aspect, and the cost involved . Chlorophyll, betalain, flavonoids, and carotenoid pigments were explored as photosensitizers for DSSC applications …”