Photothermal‐Assisted Triphase Photocatalysis Over a Multifunctional Bilayer Paper

Photocatalysis as one of the future environment technologies has been investigated for decades. Despite great efforts in catalyst engineering, the widely used powder dispersion and photoelectrode systems are still restricted by sluggish interfacial mass transfer and chemical processes. Here we develop a scalable bilayer paper from commercialized TiO2 and carbon nanomaterials, self‐supported at gas‐liquid‐solid interfaces for photothermal‐assisted triphase photocatalysis. The photogeneration of reactive oxygen species can be facilitated through fast oxygen diffusion over triphase interfaces, while the interfacial photothermal effect promotes the following free radical reaction for advanced oxidation of phenol. Under full spectrum irradiation, the triphase system shows 13 times higher reaction rate than diphase controlled system, achieving 88.4 % mineralization of high concentration phenol within 90 min full spectrum irradiation. The bilayer paper also exhibits high stability over 40 times cycling experiments and sunlight driven feasibility, showing potentials for large scale photocatalytic applications by being further integrated into a triphase flow reactor. A scalable TiO2/C bilayer paper for photothermal‐assisted photocatalytic phenol oxidation is reported. The triphase interface ensures the fast supply of oxygen reactant at high photon flux, whilst the photothermal effect promotes the subsequent phenol free radical reaction kinetics. Cycling stability, sunlight feasibility, oxygen concentration compatibility and flow condition demonstrate the possibility for large‐scale photocatalytic applications.