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Aiming at photodegrading pollutants under room-light excitation, we fabricated TiO2 composite catalysts driven by weak visible light through adsorbed-layer nano reactor synthesis. Fe2O3 coupling and codoping by nonmetal elements were performed to enhance activity under irradiation of weak room light. By UV visible diffuse reflectance spectra, high resolution transmission electron microscopy, X-ray diffraction, PL spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy analyses, the results showed that Fe2O3 coupling could extend the spectral response of the catalysts into the visible-light region. Two Fe2O3 coupling sequences exerted different effects on the microstructure of the catalysts. Fe2O3 strongly interacted with TiO2 in the SiO2-Fe2O3-TiO2 catalysts, 9 causing a more obvious visible-light response of SiO2-Fe2O3-TiO2 catalysts than SiO2-TiO2-Fe2O3 catalysts. Fe2O3 also significantly affected the crystallization of TiO2 in SiO2-Fe1O3-TiO2 catalysts, thus introducing many shallow trapping sites for charge carriers. Nonmetal element doping, especially the codoping of N and B, could also enhance the visible-light response and the light absorbance of composite catalysts, as well as introduce impurities unto the catalyst structure. consequently, the activity under room-light irradiation was greatly improved: The degradation rate of the SiO2-TiO2-Fe2O3 catalyst codoped with N arid B was approximately 45%, which was more than twice that of-SiO2-TiO2-Fe2O3 catalyst.