Carbon nanomaterials can stably produce electrical energy through their interaction with water. Nanocarbon materials can harness energy from almost any form of hydraulic power and continuously generate electrical energy up to several volts, a phenomenon known as the "hydrovoltaic effect."
For hydrovoltaic devices, the current density is in tens of microamps, the output power is generally between microwatt and milliwatt, and the power density is generally less than 10 Wm-2 .