MXene-Enhanced Ionovoltaic Effect by Evaporation and Water Infiltration in Semiconductor Nanochannels

In recent years, substantial attention has been directed toward energy-harvesting systems that exploit sunlight energy and water resources. Intensive research efforts are underway to develop energy generation methodologies through interactions with water using various materials. In the present investigation, we synthesized sodium vanadium oxide (SVO) nanorods with n-type semiconductor characteristics. These nanorods facilitate the initiation of capillary phenomena within nanochannels, thereby enhancing the interfacial area between nanomaterials and ions. The open-circuit voltage (V_OC) was 0.8 V, and the short-circuit current (I_SC) was 30 μA, which were continuously monitored at room temperature using a 0.1 M saltwater solution. Additionally, we achieved enhanced energy generation by efficiently converting light energy into thermal energy using MXene, a 2D material. This was accomplished through the photothermal effect, leveraging the inherent semiconductor characteristics. Under light exposure, the system exhibited improved performance attributed to heightened ion diffusion and increased conductivity. This phenomenon was a result of the concerted synergy between ions and electrons facilitated by a semiconductor nanofluidic channel. Ultimately, we demonstrated an application to showcase real-world viability. In this scenario, electricity was harvested through a smart buoy floating on the water, and, based on this, data from the surrounding environment was sensed and wirelessly transmitted.