Spectrally Coordinated Plasmonic–Photothermal Photocatalysts for Mineralization of Mixed Indoor VOCs Under White LED Illumination

ABSTRACT Indoor volatile organic compounds (VOCs) remain a major health concern, yet conventional photocatalysts show limited effectiveness under low‐intensity indoor lighting. Here, a spectrally coordinated plasmonic–photothermal–photocatalytic architecture integrating Cu(II)‐grafted TiO 2 (CuT), yolk–shell Au@SiO 2 (AuSi), and reduced graphene oxide sheets (GS) is presented for efficient mixed‐VOC mineralization under white light‐emitting diode (LED) illumination. Rather than acting as a simple multicomponent composite, this architecture couples partially overlapping but preferential spectral contributions across the LED spectrum: CuT drives visible‐light photocatalytic oxidation, AuSi contributes localized surface‐plasmon‐resonance‐induced electric‐field enhancement near CuT, and GS converts longer‐wavelength photons into localized heat to accelerate interfacial oxidation kinetics. Compared with CuT and binary controls, the composite enhances reactive oxygen species generation, CO 2 formation, and humidity tolerance. CuT/AuSi‐GS enables near‐stoichiometric CO 2 formation during CH 3 CHO/C 7 H 8 mixed‐VOC mineralization at 10 ppmv within 1 h and maintains over 80% CO 2 yield throughout 168 h of continuous‐flow operation at 2 ppmv. Chamber‐scale validation in a 64‐L reactor indicates the feasibility of VOC mineralization under a dedicated white LED source. Operando infrared spectroscopy traces stepwise oxidation of oxygenated and aromatic VOCs toward CO 2 , while wavelength‐dependent activity, spectral‐overlap analysis, thermal profiling, complementary spectroscopy, and simulations support coordinated energy utilization and deep mineralization under indoor white LED illumination.