Keplerate-Type Polyoxometalates-Based Triboelectric Nanogenerator for Higher Performance via the Morphology...

The tribe-material is the key factor affecting the performance of triboelectric nanogenerators (TENGs). Inorganic materials have higher heat resistance and stability than widely used organic materials. However, the weaker tribe-property limits the application of TENGs. Modulating surface roughness by changing particle shape and size is a simple way to increase performance for TENGs. Polyoxometalates (POMs) have unrivalled structural diversity and can self-assemble to form different nanostructures. In this study, we propose [{(NH₄)₄₂[Mo₇₂ ^VIMo₆₀ ^VO₃₇₂(CH₃COO)₃₀ (H₂O)₇₂] ⋅ ca.300H₂O ⋅ ca.CH₃COONH₄)}-Mo₁₃₂] and [{Na₈K₁₄(VO)₂[{(Mo^VI) (Mo₅ ^VIO₂₁)(H₂O)₃]}₁₀{(Mo^VI)Mo₅ ^VIO₂₁(H₂O)₃ (SO₄)}₂{V^IVO(H₂O)₂₀} {V^IVO}₁₀({KSO₄}₅)₂] ⋅ 150H₂O)}-Mo₇₂V₃₀] with blackberry structure which are cured and prepared into film by spin-coating technique, are used as positive tribe-materials for the first time in the field of TENGs. Keplerate-type POMs can form blackberry structures with higher dispersibility and flexibility, which can be used to control surface roughness by regulating the size of particles. The discovery proves that the particle size influences the surface roughness, which adjusts the output of TENGs. According to our findings, Mo₁₃₂-h-TENG generates an output voltage of 29.3 V, an output charge of 8 Nc, which is 2-3 folds higher than Mo₁₃₂-TENG, and a maximum power density of 6.25 mW ⋅ m^-2 at 300 MΩ. Our research provides that altering the dimensional size can be an available way to raise the output of TENGs.