Facile synthesis of hierarchical CdS nanoflowers for efficient piezocatalytic hydrogen evolution

Piezocatalytic hydrogen evolution has emerged as a promising field for the collection and utilization of mechanical energy, as well as for generating sustainable energy throughout the day. Hexagonal CdS, an established semiconductor photocatalyst, has been widely investigated for its ability to split water into H₂. However, its piezocatalytic performance has received less attention, and the relationship between its structure and piezocatalytic activity remains unclear. In this study, we prepared 3D ultrathin CdS nanoflowers with high voltage electrical response and low impedance. In pure water, without the use of any cocatalyst, CdS exhibited a piezoelectric catalytic hydrogen production rate of 1.46 mmol h^-1 g^-1, which was three times higher than that of CdS nanospheres (0.46 mmol h^-1 g^-1). Furthermore, the value-added oxidation product H₂O₂ was produced during the process of piezoelectric catalysis. These findings provide new insights for the design of high-efficiency piezoelectric catalytic hydrogen production.