Construction of quantum-scale catalytic regions on anatase TiO2 nanoparticles by loading TiO2 quantum dots for the photocatalytic degradation of VOCs

Abstract We constructed quantum-scale catalytic regions on the surfaces of TiO2 nanoparticles by loading TiO2 quantum dots (QDs) with a two-step method. The removal rate and mineralization efficiency of toluene were measured and then used in evaluating the oxidation performance of the prepared samples. A home-built atmospheric surface photovoltage spectrometer and X-ray photoelectron spectrometer were used in analyzing band alignment across the interface between TiO2 QD and TiO2 particle and the transfer of charge carriers at the surface. Results showed that an upward band bending formed from the TiO2 particle to the TiO2 QD and promoted the accumulation of holes at the QD side. Moreover, the QD and surrounding substrate TiO2 formed a quantum-scale catalytic region, improving the reaction probability of electron-hole pairs and corresponding intermediates. The mineralization efficiency of toluene in QD-loaded TiO2 reached 95.8%. The synthetic method is green and simple, showing potential in scale production and industrial application.