Interfacial chemical bonding effect on the photocatalytic activity of TiO2-SiO2 nanocoupling systems

► TiO2 nanoparticles were deposited onto the surfaces of mesoporous SiO2. ► The TiO2 particles were anatase crystals firmly combined on the SiO2 surfaces. ► The bandgap of TiO2 was widened by the coupling with the SiO2. ► The coupling with the SiO2 enhanced the UV-light-activity of TiO2. ► DFT calculations suggested the lowering of the valence band edge of TiO2.