A Computational Framework for Benchmarking the MXene Family as a Triboelectric Nanogenerator Toolbox

MXenes stand out in Triboelectric Nanogenerator devices due to their tunable surface terminations, structural diversity, and excellent electrical conductivity. However, no consensus has been reached when comparing the performance of MXenes. This study presents the first theory-driven framework that links the triboelectric behavior of MXenes to their atomic-scale properties. It also introduces a computational approach for benchmarking triboelectric materials, offering an alternative to the traditional triboelectric series method. By combining analytical models with density functional theory (DFT) calculations, we evaluate 48 MXene members (M₂XT₂, M = Ti, V, Cr, and Mn; X = C and N; and Tx = F, O, OH, Cl, H, and N) based on key physicochemical parameters: bandgap, work function, surface charge density, and effective density of states. Results highlight the exceptional potential of specific MXenes, such as Mn₂CF₂, Mn₂NF₂, Ti₂NN₂, and Cr₂CO₂, as negative friction layers and electron trappers due to their high work function and superior charge density. Additionally, OH MXenes like V₂C(OH)₂, Cr₂N(OH)₂, Ti₂C(OH)₂, and Ti₂N(OH)₂ demonstrate optimal performance as positive friction layers.