The Role of Surfactants in Photogalvanics: Solar Energy Conversion and Storage in the Sodium Lauryl Sulphate–Thymol Blue–Mannose System

Abstract

Sodium lauryl sulphate (SLS) was used as a surfactant, thymol blue as a photosensitizer and mannose as a reductant in a photogalvanic cell to improve the conversion efficiency and storage capacity of such cells to achieve commercial viability. The photopotential and photocurrent generated were 635.0 mV and 100.0 µA, respectively. The effect of various parameters including concentration of photosensitizer, reductant and surfactant, pH and diffusion length on the cell properties was observed. The observed conversion efficiency and the maximum power of the cell were 0.23% and 24.60 µW, respectively. The fill factor was 0.25 at the power point of the cell. The photogalvanic cell can be used for 37 minutes in the dark following illumination for 120 minutes. The current-voltage characteristics of the photogalvanic cell were studied experimentally. All of the results observed for the system were lower in absence of surfactant. The absorption spectra of the systems with and without surfactant were also studied.

Study of KOH as alkali for enhancing performance of photo-galvanic cell in transparent cylindrical cell design

“…Further, the reductant molecule is supposed to be a non electro-active sacrificial reductant species [ 7 ]. The diversity of reductants like d -Xylose [ 8 ], Arabinose [ 9 ], Mannose [ 10 ] , Fructose [ 11 ] , Formic Acid [ 12 ] , formaldehyde [ 13 ] , oxalic acid [ 14 ] , etc. Similarly, the diversity of the surfactant materials like Benzalkonium chloride [ 14 ] , sodium lauryl sulfate (SLS) [ 15 ] , Tween 60 [ 16 ], Cetrimonium bromide [ 17 ] , Diocyle Sulphosuccinate [ 18 ], Cetyltrimethylammonium bromide [ 19 ], etc.…”

“…Therefore, the alkali medium is also one of the main fabrication components for PG cells. Most of the reported photogalvanics have exploited NaOH as the alkali material [ [10] , [11] , [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] , [8] , [9] ]. Although, the NaOH based photo-galvanics shows good electrical output, but it is plagued with some drawbacks like shorter shelf life, high cost, unsafe for skin, low conductivity, low water solubility, etc.…”