The performance and longevity of concrete structures are significantly compromised by prolonged exposure to harsh environments. Photocatalytic coatings represent a promising protective strategy, but their effectiveness is constrained by the inherent limitations of single-mechanism catalysis, specifically insufficient stability and the rapid recombination of photogenerated charge carriers. To address these challenges, this study aims to develop an efficient and durable cement-based functional coating based on BaTiO3/Bi2O3 heterojunction, elucidate the underlying synergistic piezo-photocatalytic mechanism and demonstrate its practical application for degrading organic pollutants.
BaTiO3/Bi2O3 nanomaterials with different molar ratios were synthesized via high-temperature calcination. Their structural, optical and piezo-photocatalytic properties were systematically investigated. Subsequently, the optimized nanomaterial was then incorporated into a polydimethylsiloxane matrix and applied as a coating on cement-based substrates. The coating’s performance and durability were evaluated under simulated environmental conditions.
The construction of BaTiO3/Bi2O3 heterojunction significantly broadens the light response range, with the optimal BaTiO3/Bi2O3-1:1 exhibiting a narrowed bandgap of 2.57 eV. At the same time, the synergistic effect of piezoelectric effect and photocatalysis makes the degradation rate of methylene blue of nanomaterials 1.99 times higher than that of pure Bi2O3. Subsequently, polydimethylsiloxane-based coating incorporating the optimized BaTiO3/Bi2O3-1:1 demonstrates excellent performance, including 92.2% MB degradation within 100 min, robust cyclic stability retaining 85% efficiency after five consecutive cycles and no signs of corrosion after 90 days of seawater immersion.
This study presents the demonstration of integrating piezo-photocatalytic BaTiO3/Bi2O3 heterojunction into a cement-based coating. It provides a practical, highly stable coating solution with exceptional long-term durability in harsh environments, which offers significant theoretical and technical support for the development of advanced intelligent protective coatings for sustainable infrastructure.
