Department of Chemistry, Jai Narain Vyas University, Jodhpur, Rajasthan, 342033, India.
Sci Rep. 2022 Aug 7;12(1):13518. doi: 10.1038/s41598-022-17647-5.
In the present work, the photogalvanic cells have been studied with respect to the photo-stability and the long-term use of the electrolyte based on crude aqueous spinach extract sensitizer for solar energy harvesting. Further, the nature of chemical components present in the old and photo-decayed electrolyte and their current generation capacity has also not been investigated so far otherwise it is of much significance for durable use of the same electrolyte in cells. In earlier studies, the steady-state photo-generation of current for about two hours from crude spinach extract-based cell has been shown during illumination. But, the data for only two hours of the steady-state current generation is not sufficient to show the feasibility of working with photogalvanic cells. Therefore, to fill this research gap of lack of characterization of sensitizers' molecules of crude spinach extract and lack of study on long-term use of this electrolyte (crude spinach extract-surfactant-reductant-alkali-water), the present extensive study has been done. The observed spectrum of crude spinach extract resembles that of chlorophyll-protein complex showing it is the main chemical component in extract absorbing light. A strong acid adversely affects the extract's photogalvanics and high pH is friendly to the physiological and photogalvanic activity of the extract. The spectra of illuminated and very old crude spinach extract-NaOH-Sodium lauryl sulfate (NaLS)-Fructose photogalvanic electrolyte solution show negligible absorbance (540-700 nm) and zero absorbance (at 700 nm) suggesting the absence of chlorophyll due to its photo-degradation. When this photo-degraded electrolyte is again illuminated, the power output obtained is nearly equal to that for the first time illuminated fresh electrolyte. The observed current at zero time and after 2641 h from the same electrolyte used in long term is 50 mA cm and 40 mA cm, respectively. It means that the fresh crude spinach extract, as well as the photo-degraded extract at high pH, are almost equally capable of power generation.
在本工作中，研究了基于粗天然菠菜提取物敏化剂的电解质的光电稳定性和长期使用，以用于太阳能收集。此外，迄今为止，尚未研究旧的和光降解的电解质中存在的化学物质成分的性质及其电流产生能力，否则这对于在电池中持久使用相同的电解质非常重要。在早期的研究中，已经显示了基于粗菠菜提取物的电池在光照下约两小时的稳态光电流产生。但是，只有两个小时的稳态电流产生数据不足以证明使用光电电池的可行性。因此，为了填补缺乏粗菠菜提取物敏化剂分子的表征以及缺乏对这种电解质（粗菠菜提取物-表面活性剂-还原剂-碱-水）长期使用的研究的空白，进行了广泛的研究。粗菠菜提取物的观察光谱类似于叶绿素-蛋白质复合物的光谱，表明它是提取物中吸收光的主要化学物质。强酸会对提取物的光电产生不利影响，而高 pH 值对提取物的生理和光电活性是友好的。照射后的粗菠菜提取物-NaOH-十二烷基硫酸钠（NaLS）-果糖光电电池电解质溶液的光谱和非常旧的粗菠菜提取物-NaOH-十二烷基硫酸钠（NaLS）-果糖光电电池电解质溶液的光谱显示出可忽略的吸光度（540-700nm）和零吸光度（700nm），表明由于光降解，叶绿素不存在。当再次照射这种光降解的电解质时，获得的功率输出几乎与第一次照射新鲜电解质时相同。从长期使用的相同电解质中获得的零时间和 2641 小时后的观察电流分别为 50mAcm 和 40mAcm。这意味着新鲜的粗菠菜提取物以及高 pH 值的光降解提取物几乎都具有同等的发电能力。
