Visible light-driven photocatalysis of doped SrTiO3 tubular structure

Insight into the enhanced photocatalytic activity of Mo and P codoped SrTiO3 from first-principles prediction

In this study, the synergistic effect of cation codoping (Mo and the cation P) on the band structure of SrTiO₃ is demonstrated to enhance its photocatalytic activity. The electronic structure and optical properties of (Mo + P) codoped SrTiO₃ are examined by performing GGA + U calculations. The results show that the strong hybridization between the Mo 4d states and the O 2p states assisted by the non-metal P leads to the formation of fully occupied and delocalized intermediate states (IBs) near the valence band of SrTiO₃. The proximity of IBs to the valence band resulted in the ability to separate photo-excited electrons from reaction holes, which helps to ensure efficient electron replenishment reducing the probability of trapping electrons from the CB. This kind of metal Mo and non-metal P-compensated codoping can efficiently narrow the band gap and enhance the visible-light absorption. Moreover, the positions of the band edges after codoping (Mo + P) are found to be thermodynamically favorable for water splitting.

Continuous solid solutions of Na0.5La0.5TiO3–LaCrO3 for photocatalytic H2 evolution under visible-light irradiation

(Na_0.5La_0.5TiO₃)_1−x(LaCrO₃)_x solid solutions showed enhanced visible-light-driven photocatalytic activities for H₂ evolution due to the narrowed bandgaps and increased lattice distortion.

Enhanced photodegradation of pentachlorophenol by single and mixed cationic and nonionic surfactants

The photocatalytic degradation of pentachlorophenol (PCP) using a TiO(2) catalyst in a surfactant-containing system was investigated. PCP abatement by photocatalysis was significantly enhanced by the addition of cationic and nonionic surfactants, both single and mixed, at appropriate concentrations. The enhanced photodegradation can be mainly attributed to the formation of admicelles on the TiO(2) surface. This phenomenon can lead to the incorporation of more PCP, thereby providing TiO(2) with remarkably higher capture rates for target pollutants. Hence, PCP was rendered easily available to photo-yielded oxidative radicals on the catalyst surface. Notably, mixed cationic-nonionic surfactants yielded much higher photodegradation efficiencies than the corresponding single surfactants, indicating the existence of a synergistic effect in the complex system. The adsorption behavior of PCP on TiO(2) in the surfactant solutions was investigated to elucidate this synergism. Fourier-transform infrared (FTIR) spectroscopy was adopted to gain insight into the structural changes induced by the surfactants and a better understanding of the surfactant-assisted photocatalytic degradation mechanism was obtained.