Spontaneous polarization-driven charge migration in BaTiO3/Co3O4/C for enhanced catalytic performance

Abstract

Ferroelectric spontaneous polarization is a common physical phenomenon that stems from the displacement of positive and negative charges in opposite directions within ferroelectric materials. Herein, ferroelectric BaTiO₃/Co₃O₄/C materials were prepared and ferroelectric spontaneous polarization was used to successfully drive the efficient transfer of intrinsic free charges. This led to the acceleration of the Co³⁺/Co²⁺ cycle and enhancement of peroxymonosulfate (PMS) activation efficiency. The catalytic activity of as-obtained BaTiO₃/Co₃O₄/C initially increased and then quickly decreased with the increase in the concentration of the triblock polymer (P123), with the best catalytic activity achieved at a P123 concentration of 4 g L⁻¹. The degradation rate constant of the BaTiO₃/Co₃O₄/C + PMS system was 5.6 times and 68 times higher than those of the BaTiO₃/Co₃O₄ + PMS system and Co₃O₄ + PMS system, respectively. This was ascribed to the synergy of ferroelectric spontaneous polarization and C-induced electron transfer. Complete degradation of methylene blue was achieved within 8 min in the BaTiO₃/Co₃O₄/C + PMS system, and the main active species were holes (h⁺), SO₄˙⁻, and ¹O₂. Moreover, spontaneous polarization played an important role in this catalytic process. This study provides a novel strategy to enhance the Co³⁺/Co²⁺ cycling process for promoting PMS activation.