Reinforcing piezo-photocatalytic properties and enhancing RhB degradation efficiency of Ce-doped Bi4Ti3O12: mechanistic insights

Abstract

Piezo-photocatalysis offers a cutting-edge solution to tackle environmental pollution and energy challenges by leveraging mechanical energy for photoelectric conversion. However, the widespread application of piezo-photocatalysis is constrained by significant carrier recombination, which limits its degradation capacity. In this study, Ce⁴⁺-doped Bi₄Ti₃O₁₂ (BTCeO) nanosheets were synthesized via the molten salt method to serve as piezo-photocatalysts. To elucidate the exceptional piezo-photocatalytic properties of BTCeO nanosheets, comprehensive characterization was conducted and a mechanism along with potential degradation pathways was proposed. Among the synthesized materials, 5% BTCeO exhibited superior piezo-photocatalytic activity, achieving a remarkable rhodamine B (RhB) degradation efficiency of 98.24% in 20 min under simulated sunlight and ultrasonic vibration. The corresponding degradation rate constant (k = 0.1932 min⁻¹) was approximately 3.2 times higher than that of pristine Bi₄Ti₃O₁₂ (k = 0.0602 min⁻¹). The enhanced performance is attributed to an optimal Ce doping level, which improved the band structure and increased the density of active sites on the nanosheet surface. Furthermore, the piezoelectric potential generated under ultrasonic vibration effectively mitigated the polarized charge shielding effect, thereby boosting overall piezo-photocatalytic efficiency. This work provides a foundation for the design of advanced piezo-photocatalysts and their application in environmental remediation.