Ambient evaporation-induced electricity generation in activated carbon-water interfaced three-dimensional hydrovoltaic device

Green energy-based power generation is a most rising topic in scientific society. Carbon water interaction-based hydrovoltaic (HV) power generation is a futuristic current research theme to generate power; however, the actual process remains an open question. Here in this work, a novel three-dimensional (3D) tubular HV device is fabricated, and its voltage distribution is analyzed. Under ambient conditions, a single tubular activated carbon hydrovoltaic (TAC) device can generate a voltage of up to 0.9 V and a current of up to 0.7 mA. Moreover, the outstanding power deliver from TAC is nearly 600 μW for 1.2 g of active materials, and it is stable for more than ten days without any external light, wind, or heat. Further voltage improvement is tested with various factors such as light, heat, and humidity. Based on water flow-induced potential, 4 TACs can light an LED for successive ten days under ambient conditions (without any external energy supply). Moreover, the fabricated TAC device shows excellent self-life after one year of the experiment. Overcoming the two-dimensional (2D) HV devices, this self-charging 3D tubular high-power configuration is a low-cost HV device based on activated carbon and has advantages for practical applications.