Ultrafast piezocatalytic organic pollutant degradation enabled by dynamic spin state regulation of cobalt in nano-ferroelectrics

Ferroelectric materials are gaining increasing attention for the development of advanced catalytic technologies due to their field-responsive polarization states. However, achieving dynamic optimization of catalytic activity using ferroelectrics remains a fundamental challenge. Inspired by the force-adaptive mechanisms of fish scales, we introduce an intracrystalline force regulation strategy to dynamically control cobalt spin states and enhance peroxymonosulfate (PMS) activation in Fenton-like processes. This approach utilizes BaTi 0.92 Co 0.08 O 3-δ (BTC-8) nano-ferroelectrics, where ultrasound irradiation generates a built-in electric field that drives electrons towards cobalt sites. This electron transfer is further facilitated by electronegativity differences between cobalt and barium/titanium ions. The resulting piezo-driven electron flow promotes continuous regeneration of high-spin Co 2+ , enhancing PMS adsorption and SO 4 -OH bond cleavage, leading to increased production of ·SO 4 - and singlet oxygen ( 1 O 2 ) for organic pollutant degradation. Consequently, BTC-8 achieves a reaction rate ( k =1.7960 min -1 ) 29.93 times higher than that of pure barium titanate, surpassing previously reported PMS activation and piezocatalytic systems. This work represents a shift from static electronic structure design to dynamic electronic engineering in the development of advanced catalytic strategies for water remediation. We introduce an intracrystalline force regulation strategy to enhance peroxymonosulfate (PMS) activation efficiency for pollutant degradation using BaTi 0.92 Co 0.08 O 3-δ nano-ferroelectrics. Ultrasound stimulation facilitates the rapid regeneration of high-spin Co 2+ through a combination of piezo-potential and electronegativity differences, leading to increased production of sulfate radicals (·SO 4 - ) and significantly enhanced pollutant degradation. • BTC-8: Novel Co-doped BaTiO 3 nanopowder for efficient PMS activation. • Dynamic spin state regulation enhances piezocatalysis via built-in electric fields. • BTC-8 enables ultrafast RhB degradation ( k = 1.7960 min -1 ) through piezocatalysis.