Sintering-induced strained SrCO3 impurities in SrTiO3 enhance low-frequency tribocatalytic degradation of organic pollutants

Abstract

Water contamination by organic pollutants, such as dyes, poses significant environmental and health risks, necessitating the development of efficient and sustainable degradation methods. Tribocatalysis, utilizing mechanical energy to generate reactive triboelectrons, presents an effective approach under ambient conditions with or without external illumination. In this work, SrCO₃–SrTiO₃ (SCO@STO) composite catalysts were synthesized via conventional ceramic processing, with sintering temperatures adjusted (1000 °C and 1150 °C) to control lattice strain and oxygen vacancy concentrations. Experimental results showed that these sintering conditions significantly influenced the catalytic performance. Specifically, STO(A)‒1000 exhibited superior degradation efficiency under illumination due to abundant oxygen vacancies extending photogenerated carrier lifetimes and synergistically enhancing photocatalysis combined with triboelectrons from mechanical stirring, achieving nearly complete degradation of methylene blue (MB, 97 %) within 1 hour. Conversely, STO(A)‒1150 demonstrated higher catalytic performance in dark conditions, attaining 100 % degradation of Rhodamine B (RhB) within 48 h, primarily due to enhanced strain-induced triboelectric charge generation. The interplay among band alignment, oxygen vacancies, and lattice strain in SCO@STO composites highlights a versatile strategy for optimizing organic pollutant degradation under diverse environmental conditions, advancing effective environmental remediation.