Liquid–Liquid–Solid Triphase Interface Microenvironment Mediates Efficient Photocatalysis

Rational interfacial microenvironment design and modulation are crucial to photocatalysis performance. Herein, we report a photocatalytic system with a liquid (water)–liquid (organic liquid)–solid (L–L–S) triphase reaction interface microenvironment and demonstrate its utility in semiconductor-mediated photodegradation. The triphase system was fabricated using TiO2 nanowire arrays as the solid phase and polydimethylsiloxane as the inert organic liquid phase. The presence of the polydimethylsiloxane layer was confirmed via cryotransmission electron microscopy analysis, and the presence of the L–L–S interface was demonstrated using three-dimensional (3D) laser scanning confocal microscopy. Based on this triphase system, the concentrations of reactant O2 and organic molecules could be both significantly improved at the interface microenvironment, leading to over 30 times higher reaction kinetics than that of a conventional liquid–solid (L–S) diphase system. Moreover, the L–L–S system exhibited excellent stability, and the design showed universal applicability. These findings highlight the importance of interface architecture design and reveal an effective path for the development of efficient catalysis systems.