Fu Der Mai

From the perspective of sustainable development of the earth, the use of environmentally friendly water in various fields of science and harvesting solar energy for available energy generation are very worthy developments. We recognize that the properties of water and its associated activities depend to a large extent on the strength of hydrogen bonds (HBs) formed among water molecules themselves. However, because our understanding of water at the molecular level remains uncertain, today all well-known properties of water are generally described as properties of inert, bulk water due to the tetrahedral hydrogen-bonded network. Some recent studies showed that the local HB structure of water confined in nano-sized spaces or at interfaces can change, thus affecting properties of the water, but since such a small amount of water only exists at the nanoscale, its applicability is greatly limited. Recently, various free-standing and long-lived functional waters that can be fabricated in small quantities have been proposed in the literature to increase practical applications in various fields. It was reported that this treated water can remain in a metastable state, which means that its unique properties can be maintained for a period of time. For example, electrospinning spray-engineered water and cold atmospheric pressure plasma-activated water were prepared as alternative green disinfectants. Some researchers also developed micro-sized water droplets for green reduction reactions, while magnetized water was also developed into active water to create interesting synthesis reactions. The development and utilization of these active waters differ from the traditional view of solvent water as a bystander, which does not really participate in reactions. In this work, we propose an innovative application of solar energy- generated active pure water (APW) with reduced HBs to enhance chemical reactions and physical procedures. Compared to conventional deionized water (DIW), the generated APW possessed a lower specific heat of ca.

0.96. The swelling degree of artificial skin in APW significantly increased by ca. 29%. Moreover, the density of an ethanol/APW solution significantly increased by 0.21% due to more free water molecules being available in APW to form stronger HBs with ethanol. Encouragingly, efficiencies of hydrogen evolution reactions performed in an APW-based acidic solution and oxygen evolution reactions performed in an APW-based basic solution significantly increased by 42% and 17%, respectively, compared to DIW-based solutions.

Audience Take Away:

• Solar energy-generated active pure water (APW) with reduced hydrogen bonds
• Enhanced hydrogen and oxygen evolution reactions utilizing APW
• APW can create a more-effective green process in physical and chemical fields