Advancing Humidity-Resistant Triboelectric Nanogenerators Through MoS₂-Encapsulated SiO₂ Nanoparticles for Self-Powered Gas Sensing Applications

In this study, the humidity-resistant triboelectric nanogenerators (TENGs) utilizing MoS₂-encapsulated SiO₂ nanoparticles (NPs), aimed at enhancing self-powered gas sensing applications, are reported. The core-shell structure, featuring a thin MoS₂ layer uniformly grown on SiO₂, addresses common humidity-induced performance degradation. The growth mechanism involves the decomposition and sulfidation of molybdenum species, with MoS₂ selectively nucleating on SiO₂ to form a stable, hydrophobic shell. This MoS₂ layer effectively shields the SiO₂ interface from water molecule penetration, thus stabilizing charge density and significantly reducing charge decay, even under high humidity conditions. TENGs constructed with these core-shell NPs exhibit high triboelectric charge density and exceptional durability, retaining more than 70% output over 25 h at 99% relative humidity (RH). Furthermore, the fabricated TENG reliably powers a gas sensor array, enabling accurate gas detection in extreme humidity. This work demonstrates the potential of MoS₂-encapsulated SiO₂ TENGs as robust, self-powered energy solutions for environmental monitoring and wearable devices in challenging humidity conditions.