A potential biogenetic membrane constructed by hydrophilic carbonized rice husk for sustaining electricity generation from hydrovoltaic conversion

Abstract

In recent years, the research on hydrovoltaic conversion has made rapid progress, showing potential prospect in the field of power generation. However, it still faces many issues, such as expensive, uncontrollable engineering, undetermined mechanism and difficulty in commercialization. To provide a low-cost, undemanding and practical strategy, the carbonized rice husk was first used to construct a biogenetic membrane device in this work, giving a sustaining hydrovoltaic voltage at ∼160 mV. Relevant studies that associated with mechanism and key factors for hydrovoltaic process were also implemented founded on different test conditions. It is proved that the fluids flow driven by evaporation and capillary effect is an essential prerequisite for hydrovoltaic conversion. The mechanism for generating electricity should be attributed to the streaming potential theory, which can provide an electric potential difference by selective transmission of ions owing to the Debye shielding effect. Based on this as-proposed theory, the controlling projects like improving pressure difference (ΔP) of fluid, ambient temperature and humidity, which generally enhance the hydrodynamic driving force and effective flowing area, logically demonstrate positive answers on hydrovoltaic performance. Moreover, in view of the super hydrophilicity of carbonized rice husk, this biogenetic membrane has demonstrated strong sensitivity on human breath monitoring with rapid response for every breath, which provides a potential way for the practical application of hydrovoltaic effect.