Chitin/MoS₂ nanosheets dielectric films with enhanced energy density by silane surface modification

Flexible dielectric capacitor has huge application potential in modern electronics and electrical power systems. In this work, chitin-based nanocomposite films were fabricated by integrating regenerated chitin (RCH) with two-dimensional molybdenum disulfide (MoS₂) nanosheets using a facile, cost-effective and environmentally benign approach. To enhance both the dispersion stability and interfacial compatibility between MoS₂ and chitin, 3-aminopropyltriethoxysilane (KH550) was introduced as a coupling modifier to functionalize the MoS₂ nanosheets surface. This strategy can improve the dielectric properties of the matrix when the surface-modified chitin/MoS₂ nanosheets applied to film dielectric capacitor. The experimental results demonstrate that the obtained RCH-MoS₂@KH550 nanocomposite films enhanced breakdown strength and dielectric constant relative to the RCH and RCH-MoS₂ composite films. Notably, the RCH-MoS₂@KH550 composite films containing 5 wt% MoS₂@KH550 (RCH-MoS₂@KH550 5) exhibited a discharge energy density of 4.7 J cm^-3 at a breakdown strength of 400 MV m^-1, exceeding the RCH film by over twofold and showing an approximately 17% improvement compared with the unmodified RCH-MoS₂ 5 composite films. This work highlights strategies for integrating biomass and MoS₂ nanocomposite materials in dielectric energy storage applications.