Surface Phosphorylation Modulates {001}‐Faceted TiO 2 for Efficient Photocatalytic Formaldehyde Degradation

ABSTRACT This work systematically investigated the photocatalytic formaldehyde (HCHO) degradation performance of facet‐phosphated {001} TiO 2 (P‐TiO 2 ) photocatalysts. The experimental results clearly showed that surface phosphate modification significantly enhanced the photocatalytic activity, achieving complete HCHO elimination (0 ppm residual concentration after 1 h) and maintaining stable catalytic performance for 12 h, outperforming pristine TiO 2 , which only reached a 78.8% degradation efficiency under the same conditions. Combined spectroscopic and theoretical analyses indicate that stable P─O─Ti bonds enhance the intrinsic activity of P‐TiO 2 . These structural features optimize the interfacial electronic configuration, driving efficient photogenerated carrier separation and directing interfacial electrons toward adsorbed O 2 molecules. Consequently, the activated O 2 molecules exhibit weakened O─O bonds, leading to the proliferation of critical O − radicals for oxidation of HCHO. Mechanistic studies further demonstrate that O − radicals on P‐TiO 2 oxidize HCHO via a dioxymethylene (DOM) and formate intermediate pathway, with reduced reaction energy barriers. This study elucidated the pivotal role of the adsorbed phosphate in the modulation of oxygen activation and provided novel insights and practical strategies for the design of high‐efficiency TiO 2 ‐based indoor VOC purification materials.