Turbulence-Driven Piezoelectric Polarization of ZnO Nanowire/MoS₂ Quantum Dots Composite Photoelectrodes for Solar Energy Conversion

Despite the potential of ZnO-based photoelectrodes in solar energy conversion, their practical performance remains limited by a small range of absorbable wavelengths and rapid decay of photogenerated charges. Traditional strategies focusing solely on heterojunction construction often fail to address the dynamic modulation of the charge behavior during operational conditions. Here, we propose a three-dimensional nickel foam (NF)-supported ZnO nanowires/MoS2 quantum dots (ZnO NWs/MoS2 QDs) composite photoelectrode system. This design leverages synergistic dual-channel charge modulation through bandgap engineering and piezo-phototronic coupling. Specifically, the narrow bandgap of MoS2 QDs broadens the visible-light response range of ZnO NWs. Concurrently, this bandgap engineering enhances light absorption efficiency through optimized photon utilization. Under hydrodynamic conditions (400 rpm stirring), the NF substrate induces a piezoelectric polarization field in ZnO. The inherent type-II band alignment of the ZnO/MoS2 heterojunction dynamically synergizes with this field, collectively promoting directional carrier separation and migration. Experimental results revealed a 6.5-fold enhancement in photocurrent density compared to static NF/ZnO systems and a 1.17-fold improvement over their static NF/ZnO/MoS2 counterparts. This work introduces an innovative solution for enhancing light harvesting and carrier management via dynamic piezo-phototronic regulation in three-dimensional architectures, demonstrating prototype adaptive photoelectrodes with potential to advance flow-driven solar conversion technologies.