| 초록 |
The most widely used oxide photocatalyst is titanium dioxide (TiO2) because of its low cost, high photocorrosion stability and excellent activity under UV irradiation. Recently, second-generation TiO2, referred to as black TiO2, which can absorb both visible and near-infrared solar light, has triggered an explosion of interest in many important applications of TiO2. Here, we demonstrate the selective conversion of white TiO2 into black TiO2 using simple room-temperature solution processing. The reducing agent, lithium in ethylenediamine (Li-EDA), can reduce only the white rutile phase of Degussa P-25 samples mixed with anatase and rutile phases to produce disordered rutile black TiO2 with a low bandgap energy. Electrons and holes generated from the reduced black TiO2 can be efficiently separated using the white crystalline anatase due to the type-II bandgap alignment. Thus, with selective conversion of the mixed-phase TiO2, a completely new approach to enhancing solar absorption and charge separation in black and white TiO2 resulted in the best hydrogen production photocatalyst reported to date. |
