Boosting osmotic energy conversion through the non-uniform functional group distribution pattern combined with thermal and pH regulations

Nanofluidic osmotic energy conversion, a novel method for directly converting salinity gradient into electrical energy, provides an innovative solution to the global energy crisis. However, its practical application is hindered by relatively low power generation performance. This study systematically investigates the influence of functional group distribution on power generation performance by developing a numerical model based on the finite element method. The numerical model incorporates several assumptions, including the continuity hypothesis and the neglect of ion volume effects, among others. Four different functional group distribution patterns are explored, including uniform distribution and local enrichment in low-, medium-, and high-concentration regions. The results show that, compared to the traditional uniform distribution pattern, functional group enrichment in the low-concentration region leads to superior power generation performance and enhanced environmental adaptability under temperature difference and pH variations. Under a 5000-fold concentration gradient, the output power of this pattern reached 0.792 pW, an 86.5% increase compared to the uniform distribution pattern. By analyzing the mechanism of functional groups distribution in nanofluidic osmotic energy conversion, this study demonstrates the performance advantages of a specific non-uniform distribution pattern under particular conditions, providing theoretical guidance for the design and optimization of high-performance nanochannels.