Zinc oxide (ZnO) is a widely employed material for enhancing the performance of cellulose-based triboelectric nanogenerators (C-TENGs). Our study provides a novel chemical interpretation for the improved output efficiency of ZnO in C-TENGs. C-TENGs exhibit excellent flexibility and integration, achieving a maximum open-circuit voltage (Voc) of 210 V. The peak power density is 54.4 μW/cm2 with a load resistance of 107 Ω, enabling the direct powering of 191 light-emitting diodes with the generated electrical output. Moreover, when deployed as self-powered sensors, C-TENGs exhibit prolonged operational viability and responsiveness, adeptly discerning bending and motion induced by human interaction. The device’s sensitivity, flexibility, and stability position it as a promising candidate for a diverse array of energy-harvesting applications and advanced healthcare endeavors. Specifically, envisaging sensitized wearable sensors for human activities underscores the multifaceted potential of C-TENGs in enhancing both energy-harvesting technologies and healthcare practices.