Composition‐Tuned Bimetallic MOF/Poly(Vinyl Alcohol) Composite Films for High‐Performance Triboelectric Nanogenerators

Polymer triboelectric films are key components of flexible triboelectric nanogenerators (TENGs), as their composition and interfacial characteristics govern charge generation and output performance. Poly(vinyl alcohol) (PVA) is an attractive positive triboelectric polymer due to its film‐forming ability and flexibility; however, pristine PVA films exhibit limited output. Although filler incorporation improves polymer triboelectric layers, the influence of bimetallic metal‐organic framework (MOF) composition and loading remains unclear. Here, three 2‐methylimidazole‐based bimetallic MOFs, CoZn‐MOF, CoCu‐MOF, and CoNi‐MOF, were synthesized and incorporated into PVA to construct composite triboelectric films. Their performance was evaluated using vertical contact‐separation TENGs with poly(vinylidene fluoride) as the negative layer. All MOF/PVA composites exhibited enhanced output compared with pristine PVA. The optimized CoNi‐MOF/PVA TENG with 3 wt% filler achieved the best performance, delivering an open‐circuit voltage of 194 V, a short‐circuit current of 3.0 µA, and a transferred charge density of 175 µC·m −2 . It also generated 98 µW output power, charged a capacitor, powered over 100 light‐emitting diodes (LEDs), and enabled self‐powered tapping intensity and motion sensing. This work demonstrates a composition‐tuning strategy for designing MOF/PVA composite films for mechanical energy harvesting and wearable sensing.