Optimizing Hydrophilicity in NiO/Graphene Composites Via Stearic Acid Treatment for Humidity-to-Energy Applications

Converting water molecules into energy, this research field has garnered significant attention, yet it is still in its early stages of exploration. The main challenge in humidity-to-energy development is the effectiveness of material in water absorption. This article presents a study on surface modification through stearic acid treatment aimed at optimizing the hydrophilicity of hygroscopic material, thereby improving humidity energy harvesting performance. Here, we successfully synthesized a novel NiO/Graphene on cellulose substrate (NiO/Gr/cellulose) as the hygroscopic material using the sonicated solution immersion method. A humidity-to-energy device was fabricated by utilizing the NiO/Gr/cellulose, yielding an output voltage of 2.26 mV, a current density of 0.18 nA/cm², and a power output of 0.51 pW at 75% relative humidity. This research highlights the potential of NiO/Gr/cellulose with sufficient hydrophilicity as a promising hygroscopic material, offering significant future prospects in humidity energy harvesting technology.