Flexible, Multifunctional, and Durable MXene/CeO₂/Cellulose Nanofibers for Efficient Energy Conversion‐Storage Capacity Toward Self‐Powered Monitoring of Ammonia

Abstract The appeal of wearable gas sensors for Internet of Things (IoTs) necessitates flexible sensory units along with sustainable source of energy supply. The key factors required for emergence of these devices are choice of electroactive materials, flexibility, skin‐compatibility, and robustness against harsh environment. Considering this, the multifunctional MXene/CeO₂ composites reinforced with electrospun cellulose nanofibers are constructed and investigated for energy conversion, energy storage, and gas sensing applications. Among the synthesized composites, MXene/CeO₂ (10 wt%) coated onto cellulose nanofibers outperformed triboelectric nanogenerator (TENG) with open‐circuit voltage of 160 V and supercapacitor (SC) specific capacitance of 388.98 F g⁻¹ and sensing response of 212% toward 10 ppm NH₃. The fabricated devices show promising outlooks against practical challenges of influence of humid conditions and different bending states. Lastly, the self‐chargeable device is integrated and the practical implications of charging of SC through TENG and its utilization in sensor powering is demonstrated. The above findings are expected to contribute significantly in envisioning development of wearable health monitors, combining the flexibility features and facilitating autonomous measurements of NH₃ pollutant and biomarker.