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The crystal structure models of O doped CsPbX 3 (X=Cl, Br, I). [Display omitted] • O doped perovskite CsPbX 3 was studied by first principles. • New optical property of CsPbX 3 doped by O are predicted. • O changes the position of the valence band top and conduction band bottom. The electronic structures of perovskite CsPbX 3 (X = Cl, Br, I) and O doped CsPbX 3 have been studied by first principles based on density functional theory (DFT). The theoretical calculation results show that O doping leads to narrow band gap width of perovskite CsPbX 3. For pure CsPbX 3, it is found that the 6p states of Pb determines the position of the conduction band bottom and the p states of halogen determines the position of the valence band top; and for O doped CsPbX 3 , it shows that the incorporation of O is the fundamental reason for the narrowing of band gap and light absorption edge redshifting compared with that of pure CsPbX 3. [ABSTRACT FROM AUTHOR]

Ag x Si y O z has the potential to inhibit the recombination of photoinduced electron hole pairs via an internal electric field induced by asymmetrical Si–O tetrahedral chains. The strength of the [SiO 4 ] tetrahedral produces a very strong internal electric field for Ag 10 Si 4 O 13. Here, a novel and convenient synthetic strategy for nano-Ag 10 Si 4 O 13 based on a sol-gel method is proposed. A small band gap, an internal electric field and a small size ensure good efficiency for nano-Ag 10 Si 4 O 13 during all chemical dynamical processes, including charge excitation, charge separation and charge transfer. [ABSTRACT FROM AUTHOR]

The practicability of nano-powder photocatalyst is limited by the difficulty of its recovery. 3D monolithic TiO 2 photocatalyst (MTP) was printed by direct ink writing (DIW) using TiO 2 nanoparticles as solutes of tetrabutyl titanate precursor to configure printing slurry to achieve integrated regulation of microscopic and macroscopic pore structure. The SEM verified that the surfaces of skeleton-TiO 2 particles were uniformly covered by the TiO 2 nanoparticles derived from calcining gel. And a highly connected hierarchical pore structure was formed by the skeleton-TiO 2 particles and the designed 3D printing macroscopic pores, which laid the foundation for rapid capture and efficient in situ degradation of antibiotics. The nano TiO 2 powders prepared by calcined gel have narrow band gap width, which is easier to generate electrons and holes and have low recombination rate. Therefore, the core-shell structure constructed by nanoparticles derived from gel and commercial TiO 2 can effectively optimize the photocatalytic performance of MTP. The removal of tetracycline hydrochloride (TCCH) in water by MTP was used to verify the application effect of macro structure in practice, and the synergistic effect of adsorption and degradation kinetics was summarized. The dynamic adsorption effect of MTP reached 97.44 % at pH 7 for 5 h. Under simulated sunlight, MTP exhibited a synergistic adsorption-degradation effect, reaching equilibrium at 210 min. The cycle test shows that the removal rate of TCCH by MTP remains 91 % after 4 cycles. This strategy provides a good reference for the assembly of nanosemiconductor materials into environmentally friendly 3D structured systems. [Display omitted] • A novel strategy for 3D TiO 2 photocatalyst based on direct ink writing was proposed. • The 3D TiO 2 photocatalyst with high molding accuracy and good pore distribution were successfully prepared. • The microstructure of 3D TiO 2 photocatalyst is a core-shell structure in which small particles wrap large particles. • The 3D TiO 2 photocatalyst exhibit considerable dynamic adsorption and degradation properties. [ABSTRACT FROM AUTHOR]