Microstructure Engineered Photon‐Managing Films for Solar Energy to Biomass Conversion

Abstract

such as solar thermal collectors, [2] photovoltaic cells, [3] photocatalytic hydrogen production, [4] and photosynthesis. [5] Among them, photosynthesis is considered a sustainable process by which photosynthetic organisms convert solar light energy into chemical energy (biomass) using water and CO 2 . For this reason, photosynthesis has gained the increasingly concern of the researchers for applications in CO 2 biofixation [6] and the production of sustainable bioresources. [7] Compared with higher plants, microalgae show advantages in solar energy conversion through photosynthesis due to their fast growth rates and their ability to grow on non-arable land using saline water. [8] Nonetheless, photosynthetic efficiencies of microalgae are much lower than their theoretical maxima, which is predominantly attributed to the inefficient utilization of solar light reaching the microalgae. [9] To improve light utilization efficiency, genetic engineering has been explored. [10] It accelerates light-dependent reactions of microalgae and ultimately augments the photosynthesis by artificially tailoring their light-harvesting antenna size [9b] and expanding the photosynthetically active radiation (PAR) spectrum. [10a] Nevertheless, only limited microalgal strains nowadays can be genetically manipulated, [11] for example, Chlamydomonas reinhardtii (C. reinhardtii), and much effort is still needed to understand the stability and reliability of the genetically modified microalgae and other algal strains. [12] Photon management, on the other hand, provides a passive approach to increasing the photosynthesis of microalgae by Conversion of solar energy into chemical energy through natural photosynthesis plays a crucial role in sustainable energy transformation, bioresource production, and CO 2 biofixation. Nevertheless, the overall solar energy to chemical energy (biomass) conversion efficiency in the photosynthetic organisms is still unsatisfactory because of their inefficient utilization of solar light. Here, a photonic method to improve photosynthesis of a unicellular green microalga, Chlamydomonas reinhardtii, a photosynthetic organism model is reported. For this purpose, an easy-to-fabricate microphotonic film is developed to improve the spectral quality of solar light reaching the microalgae through photon management (i.e., simultaneous solar spectral conversion and directional fluorescent emission). This study demonstrates that the short-term oxygen evolution rate and the long-duration biomass production of microalgae in 200-mL laboratory photobioreactors are enhanced by a factor of 38% and 54%, respectively. In 5000-mL scaled-up bubble column photobioreactors placed outdoor under natural sunlight and weather conditions, the biomass yield is improved by more than 20% when compared to the control experiments conducted in parallel in an optically clear bubble column photobioreactor. Based on such experimental observations, the work here demonstrates the potential of photon management for promoting the solar energy...

Effect of carbon dots supplementation in Chlorella vulgaris biomass production and its composition

“…Different strategies to increase biomass production have been recently explored. For example, photonic engineering converts photons from different wavelengths to turn them into an absorbable spectrum; however, this technology is still under development (Cho et al 2019, Shen et al 2023. On the other hand, Agathokleous et al (2019) irradiated microalgae under specific red and blue light exposures to increase cell growth rate and enhance lipid production, but it has not shown economic feasibility.…”