Hydrochloric acid‐mediated synthesis of ZnFe_(2)O_(4) small particle decorated one‐dimensional Perylene Diimide S‐scheme heterojunction with excellent photocatalytic ability

The recyclable and stable ZnFe_(2)O_(4) small particle decorated one‐dimensional perylene diimide(PDI)S‐scheme heterojunction(1D PDI/ZnFe_(2)O_(4))is prepared by the hydrochloric acid‐mediated(HCl‐mediated)strategy,interestingly,the morphology of the 1D PDI/ZnFe_(2)O_(4) can also be effectively regulated by HCl‐mediated process,the existence of HCl can regulate PDI into a uniform rod structure,while the co‐existence of HCl and PDI can limit ZnFe_(2)O_(4) to become the uniform small particles.More importantly,based on the 1D rod structure of PDI and the small size effect of ZnFe_(2)O_(4),carriers can migrate to the surface more easily,which can improve the photocatalytic activity.Meanwhile,due to the appropriate energy level structure,the S‐scheme heterojunction structure is formed between PDI and ZnFe_(2)O_(4),which eliminates meaningless photo‐generated charge carriers through recombination and introduces strong redox to further enhance the photodegradation effect,thereby,1D PDI/ZnFe_(2)O_(4) exhibits excellent photocatalytic ability,under the visible light irradiation,the degradation rate of tetracycline(TC)with 1D PDI/ZnFe_(2)O_(4)(66.67%)is 9.18 times that with PDI(7.26%)and 9.73 times that with ZnFe_(2)O_(4)(6.85%).This work proposes new ideas for the assembly of magnetic organic‐inorganic S‐scheme heterojunction photocatalysts.

Eu Ions Site-selective Doping and Nonstoichiometric Chemistry of NaTaO3 in Na-rich Environment

The electronic structure of Eu-doped NaTaO3 in Na-rich environment is investigated by the first-principles theory. By simulating the two different models of Eu3＋ ions selectively located in Ta and Na sites, respectively, the band gaps of two Eu-doped NaTaO3 models were all narrowed, which were assigned to lattice defects and impurity band of the Eu dopent. For the model of Eu3＋ ions located in the Na＋ sites of NaTaO3, the new impurity band mainly composited of Eu 4f orbital appeared at the top over the valence band, indicating the enhanced oxidative ability. For the model of Eu3＋ ions located in the Ta5＋ sites of NaTaO3, a midgap state generated was located at the bottom of conduct band and the band potential shifted up, confirming the strong reductive ability in the Na-rich enviornment. The densities of electron states were significantly increased in both the conduction and valence bands in Na-rich model, which resulted in the increased carrier migration rate and thus photocatalytic activity enhancement. It is proposed that Eu3＋ ions doping at the Ta sites could enhance the reduced photocatalytic performance via controlling the nonstoichiometric Na/Ta molar ratio in the Eu-doped NaTaO3 system.

A New Inorganic 2D Framework Based on Bi-bismuth-capping Keggin Polyoxometalate with Photodegradation and Selective Absorption of Organic Dyes

A new purely inorganic 2D framework, {PMo12040Bi2（H20）2}·4H20（1）, was synthesized under solvo- thermal condition and characterized by infrared（IR） spectroscopy, thermal gravimetric analysis, UV-Vis spectroscopy, powder X-ray diffraction and single-crystal X-ray diffraction. Structural analysis reveals that compound 1 consists of Keggin unit {PMo12O40} with two bismuth atoms capping two opposite pits, leading to the bi-bismuth-capping Keggin polyoxometalate. Compound 1 not only displays excellent photodegradation activity for methyl orange（MO）, but also has a high absorption capacity for rhodamine B（RhB） and methylene blue（MB）. Moreover, compound 1 is extremely stable and easily separated from the reaction system for reuse.