Twist-engineered 2D photoelectrocatalysts for efficient and scalable green hydrogen production

Objective

One of the current bottlenecks in green hydrogen production via water electrolysis is that the most efficient electrodes are typically made from scarce and expensive noble-metals. Twist-H2 aims to overcome this limitation using earth-abundant electrodes based on 2D materials. In this action, the performance of 2D electrodes for the hydrogen evolution reaction (HER) will be tuned by the controlled interlayer twisting between their layers. The concepts of twisting and moiré superlattices remain largely unexplored for catalysis applications. This project focuses on MoS2, in which the twist angle tailors interlayer coupling, local strain and electronic structure, which are properties that can boost the HER. Early reports suggest that twisting can strongly improve the HER activity in transition metal dichalcogenides electrodes, but so far, research has covered a few synthesis-limited angles, lacking a systematic investigation on how the angle can enhance the HER, and rarely addressing stability or scalability. Twist-H2 sets two goals: (SO1) map how HER activity depends on the twist angle of homobilayer MoS2; and (SO2) test the stability and scale-up routes towards a practical application. This approach combines deterministic fabrication by mechanical exfoliation, allowing accurate control of the twist-angle, with in-operando electrochemical, optical and structural characterization, followed by a translation to larger-area electrodes. The results from this work will provide new insights into the design of electrocatalysts through moiré engineering, with potential impact not only on MoS2 electrodes for hydrogen production, but also on a broader range of 2D materials and other interesting catalytic reactions, such as oxygen evolution, CO2 reduction or ammonia production.