基于荧光太阳能聚集器和微反应器的“人造树叶”的研究

Photosynthesis, which is to convert solar energy to chemical energy, is a long-standing dream for humans and also the inevitable trend in the context of increasingly serious energy and environment problems. Inspired by the leaf, a novel solar reactor, Luminescent Solar Concentrator PhotoMicroreactor (LSC-PM) was recently proposed and developed, which can harvest and convert solar energy to achieve chemical production. This highly promising reactor has attracted wide attention, which however is still encountered with two imperative challenges: PDMS swelling and luminescent molecule instability. This work changes the reactor material PDMS to other polymers, e.g. PMMA, and compares the different kinds of polymers in aspects of luminescence stability, light absorbing efficiency, price, etc., based on which a more suitable polymer is selected to construct LSC-PM. Then to avoid direct contact between the reaction mixture and the microchannel in LSC-PM, different kinds of capillaries (e.g. glass, quartz, Pyrex, transparent fluoroplastics) are inserted into the microchannel, making LSC-PMs available for photochemical reactions using various solvents and containing multi phases. The influences of the capillary’s material, refractive index, size, and cross sectional shape are investigated. Subsequently, several meaningful photochemical reactions are performed in the new LSC-PM, e.g. photosensitized oxidation of citronellol (gas-liquid), photocatalytic S-S bond formation (gas-liquid-solid). Furtherly water splitting via visible light photocatalysis is performed, achieving photosysthesis in the LSC-PM based ‘artificial leaf’.

一种由植物树叶构造启发的，新型的太阳能反应器，即荧光太阳能聚集器（LSC）-光微反应器，近期被开发出来，实现了高效太阳能捕集和物质合成，受到了学术界的广泛关注。目前LSC-光微反应器存在两个迫切须要解决的问题：反应器材料PDMS溶胀和荧光分子不稳定。本课题首先改变反应器的材料为其他聚合物，如PMMA等，在荧光分子稳定性、光吸收效率、价格等方面对各材料进行比较，筛选出一种更适合LSC-光微反应器的材料。之后为避免反应体系与微通道的直接接触（可耐各种溶剂），向反应器微通道中引入不同种类（如各种玻璃、透明氟塑料）的毛细管，研究毛细管的种类、折射率、内外径和截面形状对反应器效率的影响。在新反应器中，实施若干具有实际意义的物质合成过程，如玫瑰醚的合成、二硫键的形成等，再进一步实施光催化水分解，将LSC-光微反应器发展成为能够进行光合作用的 “人造树叶”。

在“双碳”背景下，太阳能作为地球上最丰富、最清洁的可再生资源，将发挥着重要作用，而设计开发能够高效捕集并转化太阳能、适应太阳能间歇性变化的太阳能反应器，是利用太阳能的重要方面之一。针对新型太阳能反应器——LSC（荧光太阳能聚集器）-光微反应器，本项目开发了插入毛细管式的LSC-填充床型光微反应器，不仅解决了反应器溶剂耐受性差和荧光分子不稳定的问题，还实现了质量传递过程和光子传递过程的强化，在保持反应较高产率的情况下将反应速率提高了3倍。同时，本项目为LSC-光微反应器建立了自动反应控制系统，实现了在不断变化的太阳光强下反应器的稳定生产（反应转化率波动小于5%）。此外，本项目基于LSC-光微反应器搭建了太阳能储能系统，实现了太阳能转化为电能，提高了LSC-光微反应器利用太阳能的潜力。本项目的结果为未来实现太阳能化学生产以及人工树叶的发展，奠定良好的基础。