MoS2/porous carbon nanofiber heterostructures for efficient evaporation-driven generators.

Abstract

Evaporation power generators (EPGs) based on natural water evaporation can directly convert heat energy from the surrounding environment into electrical energy. However, EPGs are difficult to commercialize due to the low charge generation and transport efficiency of single material systems, resulting in unsatisfactory open-circuit voltages and short-circuit currents. Here, we step by step prepared MoS2/porous carbon nanofiber (PCNF) heterogeneous systems by electrospinning and hydrothermal methods. Electron microscope measurements proven the uniform coating of high-crystalline quality MoS2 nanosheets on PCNF fabrics, and the uneven concave-convex surface increased the specific surface area. MoS2 covered PCNF fabrics retained good hydrophilicity, which was suitable for absorbing water and keeping the surface wet during long-term evaporation. Moreover, layered MoS2 with rich surface charge improved the charge transfer of the MoS2/PCNF fabrics. As a result, the open-circuit voltage and short-circuit current of the EPGs prepared with MoS2/PCNF fabrics were improved to 0.25 V and 75 μA, respectively, compared with those based on PCNF fabrics, which demonstrated that the MoS2 coatings improved the interaction area with water and the charge transfer effect of the EPGs. This heterogeneous combination strategy provides ideas for the preparation of high-performance EPG materials.&#xD.