Hydrothermal carbonization assisted lignocellulose derived formation of ZnO/hydrochar composites through morphology evolution for an efficient photo and electrocatalytic performance

Abstract

Conversion of agricultural waste into high-value functional materials offers a sustainable pathway for environmental remediation and technological advancement. This study utilizes hydrothermal carbonization (HTC) to transform walnut shell powder (WSP) into hydrochar, which, combined with ZnO, forms energy-efficient ZnO/hydrochar composites. These composites exhibit remarkable performance in electrochemical glucose sensing and photocatalytic degradation of methylene blue (MB) dye under visible light. Electrochemical studies, including cyclic voltammetry and time-based amperometry, revealed enhanced sensitivity, stability, and a lower detection limit for glucose oxidation compared to individual ZnO or hydrochar. Photocatalytic experiments demonstrated efficient MB dye degradation due to improved charge separation and reactive oxygen species (ROS) generation. The synergistic integration of ZnO's photocatalytic properties and hydrochar's adsorptive capacity highlights the dual functionality of these composites. This research not only promotes sustainable waste management but also advances applications in glucose sensing and pollutant degradation.