Development of novel MoS2 hydrovoltaic nanogenerators for electricity generation from moving NaCl droplet

Competence of two-dimensional (2D) material e.g. MoS2 for developing efficient seawater energy harvester has been investigated as sea water stores huge amount of clean energy in its dynamic form. Hydrovoltaic nanogenerators has been fabricated using MoS2 monolayer grown by pulsed laser deposition (PLD) technique. Fabricated MoS2 nanogenerators are found to generate voltage >7 V by the dynamic flow of NaCl electrolyte over MoS2 monolayer. Good quality large area growth of MoS2 monolayer using PLD technique was confirmed by Raman spectroscopy, Photoluminescence (PL), in-situ RHEED and XPS. Obtained high voltage from MoS2 hydrovoltaic nanogenerators has been explained using equivalent circuit model considering dynamic charging and discharging process in formed electric double layer with successive movement of NaCl droplet. Substrate dependent nanogenerator performance was investigated and it was concluded that unintentional doping of MoS2 provided by underlying substrates is crucial for enhancing the power generation. Present work opens the possibility of using MoS2 monolayer as practical nanogenerator for energy harvesting from sea water (0.6 M NaCl) as demonstrated. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

In this study, the capability of two-dimensional material MoS2 for developing efficient seawater energy harvester was investigated, resulting in the successful fabrication of hydrovoltaic nanogenerators generating voltage >7 V. The quality large area growth of MoS2 monolayer using pulsed laser deposition technique was confirmed, and the unintentional doping of MoS2 provided by underlying substrates was found to be crucial for enhancing power generation.