Biomass Waste‐Derived Hierarchically Porous Carbon‐Reinforced ZnS/PDMS‐Based Flexible Hybrid Piezo‐Triboelectric Nanogenerator for Energy Scavenging and Sensing

Abstract In this work, an easy, cost‐effective, and efficient approach is proposed to utilize the citrus fruit waste in energy harvesting and sensing. Hierarchically porous activated carbon (HPAC) nanostructures are derived from citrus fruit waste using the chemical activation process. The pure wurtzite 2D ZnS nanoplates are synthesized by the hydrothermal method. The HPACx‐reinforced ZnS/PDMS composite ( x = 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 wt.% HPAC)‐based flexible hybrid piezo‐triboelectric nanogenerators (HPTENGs) are designed. The introduction of HPAC as a conductive filler significantly enhances the dielectric constant, following the percolation theory. As a result, the HPAC2.5@ZnS/PDMS‐based HPTENG produces a high electrical output of ≈190 V, ≈26 µA, and ≈300 µW cm ^{− 2} for an optimum HPAC content. The HPTENG are utilized to develop a self‐charging power system and successfully operates several wearable/portable electronic gadgets. The HPTENG exhibited electrical responses with different amplitudes and shapes under various types of human movements. Furthermore, a fabricated HPTENG is proposed as a self‐powered sensor for security applications.