Research Seminar - Nikita Hanikel

Developing alternative strategies to produce potable water is of fundamental importance to address the water shortage crisis, which is projected to intensify in the next years due to global warming and population growth. Sorbent-assisted atmospheric water extraction (AWE) could be a viable strategy to tap the ubiquitous atmospheric moisture and allow for off-grid freshwater access anytime and anywhere—even in arid regions, where water is most needed. In this context, synthesis and implementation of next-generation sorbents, such as metal-organic frameworks (MOFs), is essential to unleash the full potential of this technology. Hitherto, sorbents developed for AWE have been exclusively designed to perform one water harvesting cycle per day, but the productivities attained with this approach are inherently limited by the sorbent’s capacity. In my talk, I show how a microporous aluminum-based MOF can perform an adsorption-desorption cycle within minutes under a mild temperature swing, which opens the way for high-productivity water harvesting through rapid, continuous cycling. Additionally, the favorable dynamic water sorption properties of this MOF allow it to outperform other commercial sorbents displaying excellent steady-state characteristics under similar experimental conditions. Finally, these findings are implemented in a new water harvester capable of generating ~1 L per kg(MOF) and day in the Mojave Desert (in conditions as extreme as 10% RH, 27 °C), representing an improvement by 1 order of magnitude over previously reported devices. This study demonstrates that creating sorbents capable of rapid water sorption dynamics, rather than merely focusing on high water capacities, is crucial to reach water production on a scale matching human consumption.

Nikita’s work focuses on addressing the global water shortage crisis through development of next-generation sorbents, as well as their device-level implementation. His main research goal is the synthesis and study of new metal– organic frameworks (MOFs) and covalent organic frameworks (COFs) that are suitable for atmospheric water harvesting in arid climates. In this context, he studies the water cluster formation within these crystalline frameworks by using a variety of crystallographic methods. This helps him to understand the water– framework interactions and consequently tune the material’s water sorption properties. In collaboration with Professor Ting Xu, Nikita intends to explore alternative approaches to freshwater generation and purification by employing MOF–polymer nanocomposites.