Huinan Che

The highly improved visible light photocatalytic activity of BiOI through fabricating a novel p–n heterojunction BiOI/WO3 nanocomposite

A novel BiOI/WO3 heterostructure was successfully synthesized using a facile ultrasonic process and used for the photocatalytic degradation of organic pollutants. The different BiOI loadings were investigated at the same time in this study. The heterostructure of BW-1.0 exhibited improved photocatalytic activity in comparison with pristine BiOI and WO3 with a 10.3- and 12.6-fold increase for Rhodamine B (RhB) degradation under visible light, respectively. The BiOI/WO3 heterostructured catalysts all exhibit the highest photocatalytic activity for degradation tetracycline (TC) under visible light. The excellent photocatalytic performance can be ascribed to the BiOI in close contact with WO3, which forms a heterojunction structure. This heterostructure composite photocatalyst results in an efficient charge separation at the interface, which is confirmed by photoelectron and photoluminescence spectroscopy. Moreover, trapping experiments indicated that h+ and ˙O2− were the main active species, with DMPO–˙O2− and DMPO–˙OH both being investigated. Moreover, the prepared sample shows good stability and recyclability, which are beneficial for its practical applications.

Construction and enhanced photocatalytic activities of a hydrogenated TiO2 nanobelt coated with CDs/MoS2 nanosheets

A few-layered CDs (carbon dots)/MoS2 nanosheet-coated hydrogenated TiO2 (H-TiO2) nanobelt heterostructures—referred to as CDs/MoS2@H-TiO2—with a flexible three-dimensional (3D) hierarchical configuration were prepared via a facial hydrothermal reaction. Note that the visible photocatalytic activity of H-TiO2 was improved compared with that of pristine rutile TiO2, which can be mainly attributed to the optical absorption and charge carrier trapping of oxygen vacancies and Ti3+ ions in TiO2 nanobelts created by the hydrogenation. The CDs/MoS2@H-TiO2 ternary photocatalysts exhibit excellent UV and visible photocatalytic property. Via optimizing the proportion of each component, the CDs/MoS2@H-TiO2 composite showed the highest photocatalytic degradation activity when the content of the CDs/MoS2 co-catalyst was 5.0 wt% and the content of CDs in this cocatalyst was 25%. Further study revealed that the considerable photodegradation rate under UV irradiation and a large promotion of the photocatalytic activity in both the visible and near-infrared (NIR) region originated from the synergistic effect of oxygen vacancies, interfacial modification, and the vectorial charge-transfer channel design. Our study provides a desired strategy to understand and realize a rationally designed electronic transition between a semiconductor and cocatalysts, which is of great importance for the enhancement of charge separation and obtaining improved photocatalytic performance.

Three transition metal complexes with 3,5-bis((4′-carboxylbenzyl)oxy)benzoic acid and 4′-(4-pyridyl)-2,2′:6′,2″-terpyridine: Syntheses, structures and properties

ABSTRACT Three transition metal complexes, [Cu(PYTPY)2]·Hbcb·2H2O (1), [Ni(PYTPY)2]·Hbcb·2H2O (2) and [Cd(H2bcb)2(PYTPY)] (3) [where, H3bcb = 3,5-bis((4’-carboxylbenzyl)oxy)benzoic acid, PYTPY = 4′-(4-pyridyl)-2,2′:6′,2″-terpyridine], were synthesized and characterized by elemental analysis, IR and single-crystal X-ray diffraction. Single-crystal X-ray diffraction analyses reveal that the complexes 1 and 2 crystallize in the same monoclinic P2(1)/n space group with similar cell parameters. In complexes 1 or 2, an asymmetric unit contains one Cu2+/Ni2+ ion, two PYTPY ligands, one free Hbcb2− ligand and two free water molecules. The metal center is six-coordinate via six nitrogen atoms derived from two different PYTPY ligands in a distorted octahedral coordination geometry. The isostructural complexes 1 and 2 exhibit two dimensional supramolecular layer structures based on c-π stacking interactions and hydrogen bonds. And the complex 3 crystallize in the triclinic P-1 space group. The discrete unit of 3 consists of one Cd2+ ion, two H2bcb− and one PYTPY molecule. Each Cd2+ ion is six-coordinated by three carboxylate oxygen atoms from two different H2bcb− ligands, and three nitrogen atoms from one PYTPY molecule. Zero dimensional structure of 3 is also further extended by π-π interactions and hydrogen bonds to form three dimensional supramolecular network. Furthermore, the complexes 1 and 2 exhibit relevant magnetic properties, and the complex 3 exhibit photoluminescence at room temperature in the solid state.