Ultrasonically Driven Efficient H ₂ O ₂ Production via Sulfur Alloying in Piezoelectric Bi ₂ O ₂ (Se 1−x S x ) Nanosheets

Hydrogen peroxide (H 2 O 2 ) synthesis from water and oxygen via piezocatalysis offers a sustainable alternative to the energy‐intensive anthraquinone process, but its efficiency is fundamentally limited by insufficient carrier density and sluggish surface reaction kinetics. Here we report sulfur‐alloyed piezoelectric Bi 2 O 2 (Se 1−x S x ) nanosheets that enable highly efficient H 2 O 2 production under ultrasonic excitation. The optimized Bi 2 O 2 Se 0.7 S 0.3 composition achieves a remarkable production rate of ∼4.8 mmol·g −1 ·h −1 in a pure water/air system under ultrasonication (220 W/40 kHz), outperforming most reported piezocatalytic and photocatalytic systems. Combined experimental and theoretical investigations reveal that sulfur alloying synergically enhances intrinsic polarization, increases carrier density and mobility, and promotes oxygen activation. More importantly, we uncover a dynamic strain‐mediated mechanism in which periodic tensile‐compressive lattice strain deformation modulates the binding strength of the key *OOH intermediate, overcoming the conventional Sabatier constraint that requires moderate adsorption strength. This work offers guidelines for the rational design of high‐performance piezocatalysts for sustainable chemical synthesis.