Nature-inspired CaCO₃ loading TiO₂ composites for efficient and durable photocatalytic mineralization of gaseous...

The accumulation of intermediates or final products on TiO₂ during photocatalytic volatile organic compounds (VOCs) degradation is typically neglected, despite the fact that it could result in the block of active sites and the deactivation of photocatalysts. Inspired from the natural formation of stalactite (CaCO₃ + H₂O + CO₂ ↔ Ca(HCO₃)₂), we fabricated CaCO₃ loading TiO₂ composites (CCT21) to realize the spontaneously transfer of accumulated final products (CO₂ and H₂O). Efficient and durable performance for gaseous toluene removal has been demonstrated and the cost of photocatalyst is greatly reduced by the comparison of specific activity. The introduction of CaCO₃ induces the interaction between TiO₂ and CaCO₃ to stimulate abundant activated electrons for the improvement on the adsorption and activation of reactants and the transformation of photogenerated carriers, and most importantly, facilitates the transfer of final products to release active sites and thus suppress the deactivation of TiO₂. Furthermore, we develop a facile method to immobilize CCT21 powder on flexible support, which greatly reduces the loss of photocatalysts and correspondingly enables the practical application of TiO₂-based products. Therefore, this work presents a novel nature-inspired strategy to address the challenge of deactivation, and advances the development of photocatalytic technology for environmental remediation.