太阳能人造叶子从空气中收获水以转化为氢燃料

化学工程师来自EPFL（（École polytechnique fédérale de Lausanne) have created a solar-powered artificial leaf on the basis of a porous, transparent novel electrode. The technology exhibits the potential to harvest water from the air to transform into hydrogen fuel。

基于半导体的技术是可扩展的，易于创建。一种有可能从空气中收集水并提供氢燃料（由太阳能驱动的）的设备，这是科学家多年来的重要目标。

目前，EPFL化学工程师Kevin Sivula和他的团队迈出了相当大的一步，使这一愿景更接近现实。

The researchers have come up with a clever yet easy system that integrates semiconductor-based technology along with novel electrodes that have two main characteristics: they are porous to optimize contact with water present in the air, and transparent to optimize sunlight exposure of the semiconductor coating.

当设备暴露于阳光下时，它会从大气中取水并产生氢气。研究结果在Advanced Materialsjournal on January 4^Th，2023年。

该团队的新型气体扩散电极是多孔，透明和导电的，从而允许这种太阳能技术在空气中转化水（从空气中的气态）转化。

为了实现一个可持续的社会，我们需要将可再生能源存储为可以用作工业燃料和原料的化学物质的方法。太阳能是最丰富的可再生能源形式，我们正在努力开发经济竞争的方式来生产太阳能燃料。

Kevin Sivula, Study Principal Investigator, Laboratory for Molecular Engineering of Optoelectronic Nanomaterials, École polytechnique fédérale de Lausanne

植物叶子的灵感

In their study performed for renewable fossil-free fuels, the engineers of EPFL, in collaboration with Toyota Motor Europe, took inspiration from the way plants exhibit the potential to transform sunlight into chemical energy with the help of carbon dioxide from the air.

植物将从其环境中收集水和二氧化碳，并从阳光中释放出能量的额外增强，它可以将这种分子转化为淀粉和糖，这是一种称为光合作用的过程。阳光的能量已经以淀粉和糖内化学键的形式储存。

The newly-developed transparent gas diffusion electrodes by Sivula together with his group, while being subjected to coating with a light-harvesting semiconductor material, indeed serve as an artificial leaf. This helps harvest water from the sunlight and air to produce hydrogen gas. The energy of the sunlight has been stored in the form of hydrogen bonds.

Rather than building electrodes with conventional layers that are unclear to sunlight, their substrate is normally a 3-dimensional mesh of felted glass fibers.

开发我们的原型设备是具有挑战性的，因为以前尚未证明透明的气体扩散电极，因此我们必须为每个步骤开发新的程序。但是，由于每个步骤都是相对简单且可扩展的，因此我认为我们的方法将为从太阳能驱动氢生产的气体扩散基板开始的广泛应用打开新的视野。

ÉcolePolytechniquefédéraledeLausanne的研究首席作者Marina Caretti

从液态水到空中湿度

Earlier, Sivula and other research teams have made sure that it is possible to execute artificial photosynthesis by producing hydrogen fuel from liquid water and sunlight by utilizing a device known as a photoelectrochemical (PEC) cell.

Normally, a PEC cell is called a device that makes use of incident light to stimulate a photosensitive material, similar to a semiconductor, immersed in a liquid solution to create a chemical reaction. However, for practical reasons, this process has its drawbacks, for example, it is difficult to make large-area PEC devices that make use of liquid.

Sivula had the wish to show that the PEC technology could be adapted for harvesting humidity from the air rather, resulting in the development of their new gas diffusion electrode.

Electrochemical cells (for example, fuel cells) have already been displayed to work with gases rather than liquids. However, the gas diffusion electrodes utilized previously are opaque and inconsistent with the solar-powered PEC technology.

At present, scientists are concentrating their measures on improving the system. What is known to be the ideal fiber size? The ideal pore size? The perfect semiconductors and membrane materials?

These are questions that are being tracked in the EU Project “Sun-to-X”, which is dedicated to progressing this technology and coming up with new means to transform hydrogen into liquid fuels.

Video Credit: École polytechnique fédérale de Lausanne.

来源：https://actu.epfl.ch/