As a promising method for energy harvesting , water evaporation can generate electrical energy without additional mechanical energy input. In the evaporation power generation unit based on the principle of flow potential , the low charge collection efficiency is the key factor limiting the energy output, which limits the practical application of water evaporation equipment. Based on the principle of evaporation potential , an asymmetric sandwiched hydrovoltaic device based on metallic aluminum plate and carbon cloth electrodes is designed, which not only matches the electrode, but also reduces the carrier migration route and realizes fast charge transfer and collection. The device achieves an open-circuit voltage (V oc ) of 730 mV and a short-circuit current density (J sc ) of 558 μA cm −2 , capable of producing output power density exceeding 61.7 μW cm −2 . Micro-nano electronic devices with low power consumption can be powered by integration of multiple devices. This study proposes a strategy for clean energy collection based on water evaporation.
We study the preparation of superhydrophobic polytetrafluoroethylene (PTFE) coating by a spraying method with copper mesh and aluminum plate substrates. The hydrophobicity and toughness of the resulting surfaces are investigated using water contact angles, sliding angles, rubbing tests, and impact experiments. The heat treatment is found to be the key to adjusting the microstructure as well as the wettability. Sufficient heat accumulation at 230 °C through 50 min sintering gives rise to a hierarchical structure characterised by micro spheres with lots of nanopores on their surfaces, leading to excellent water repellence proved by the large contact angle, and small sliding angle, and the complete water drop rebounce. Insufficient heat accumulation with less than 20 min sintering at 230 °C results in micro spheres without nanopores; the resulting surface presents weak water repellence in all the property tests. In addition, the porous substrate of copper mesh is proved feasible for the spraying preparation of a tough superhydrophobic surface, although it is not as good as the continuous substrate of aluminum plates.
危险品化学品经营许可证（带存储）