Simultaneous Wastewater‐to‐Hydrogen Upgrading via Mechanically Driven Piezocatalysis Over Ag‐ZnO Nanorods

ABSTRACT The growing demand for sustainable hydrogen production has driven increasing interest in wastewater as a resource for simultaneous pollutant removal and energy recovery. However, most existing wastewater‐to‐hydrogen approaches rely on external electricity, light, or chemical agents, underutilizing mechanical energy and inherent charge complementarity. Here, a piezocatalytic upgrading strategy is developed to couple organic pollutant degradation with hydrogen evolution in a single mechanically driven system. Zinc oxide nanorods serve as the piezoelectric platform, while surface‐engineered silver regulates interfacial charge extraction and directional utilization. Under mechanical excitation, piezoelectric polarization generates complementary charges that drive oxidative pollutant degradation and reductive hydrogen evolution. Using rhodamine B as a model contaminant, the Ag‐modified ZnO nanorods deliver a 90.8% increase in hydrogen yield and a 339% enhancement in degradation kinetics compared to pristine ZnO. Notably, the system demonstrates versatile applicability across various classes of pollutants and real‐water matrices, maintaining efficient upgrading performance under ambient atmosphere and low‐intensity mechanical stirring. Combined experimental and theoretical results reveal that the Ag interface enhances charge separation, water activation, and hydrogen adsorption energetics. This work establishes a dual‐functional piezocatalysis paradigm for scalable wastewater‐to‐hydrogen upgrading.