Xiaoqiang Du

Efficient photocatalytic water oxidation catalyzed by polyoxometalate [Fe11(H2O)14(OH)2(W3O10)2(α-SbW9O33)6](27-) based on abundant metals.

An eleven iron-containing nanoscale inorganic polyanionic oxide cluster was reported as the first example for exceptional photocatalytic water oxidation. Under optimal conditions, a remarkable turn-over number (TON) of 1815 ± 50 and a turn-over frequency (TOF(initial)) of 6.3 s(-1) over were achieved for water oxidation.

Hexagonal assembly of Co3V2O8 nanoparticles acting as an efficient catalyst for visible light-driven water oxidation

Co3V2O8, a uniform hexagonal sheet-shaped morphology, for the first time acted as a robust catalyst for water oxidation. Under optimal photocatalytic conditions (photoirradiation at λ ≥ 420 nm, Ru(bpy)3Cl2 as the photosensitizer, Na2S2O8 as the oxidant in borate buffer at pH = 8.5), the optimum apparent TOF of 10.9 μmol s−1 m−2 and O2 initial evolution rate of 31.7 μmol s−1 g−1 were achieved, which, to our best knowledge, are the highest values reported for heterogeneous photocatalytic water oxidation to date. Variables of the photocatalytic reaction, including catalyst concentrations, pH, dye concentrations and oxidant concentrations, were systemically studied. The oxygen atoms of the evolved oxygen came from water, as confirmed by isotope-labeled experiments. The stability of Co3V2O8 was tested and confirmed with multiple experiments (FT-IR, XRD, XPS), which indicated that Co3V2O8 is a stable catalyst under water oxidation. In addition, a mechanism of Co3V2O8 for the process of water oxidation was proposed.

Flower-like 3D CuO microsphere acting as photocatalytic water oxidation catalyst

Flower-like 3D CuO microspheres were synthesized and used to photo-catalyze water oxidation under visible light. The structure of the CuO microspheres was characterized by scanning electron microscopy, transmission electron microscopy, infrared, powder X-ray diffraction, electron dispersive spectroscopy, Raman and X-ray photoelectron spectroscopy (XPS). This is the first time that a copper oxide was demonstrated as a photocatalytic water oxidation catalyst under near neutral conditions. The catalytic activity of CuO microspheres in borate buffer shows the best performance with O-2 yield of 11.5%. No change in the surface properties of CuO before and after the photocatalytic reaction was seen by XPS, which showed good catalyst stability. A photocatalytic water oxidation reaction mechanism catalyzed by the CuO microspheres was proposed

Efficient Noble‐Metal‐Free γ‐Fe2O3@NiO Core–Shell Nanostructured Photocatalysts for Water Oxidation

Flowerlike noble-metal-free γ-Fe2O3@NiO core-shell hierarchical nanostructures have been fabricated and examined as a catalyst in the photocatalytic oxidation of water with [Ru(bpy)3](ClO4)2 as a photosensitizer and Na2S2O8 as a sacrificial electron acceptor. An apparent TOF of 0.29 μmols(-1) m(-2) and oxygen yield of 51% were obtained with γ-Fe2O3@NiO. The γ-Fe2O3@NiO core-shell hierarchical nanostructures could be easily separated from the reaction solution whilst maintaining excellent water-oxidation activity in the fourth and fifth runs. The surface conditions of γ-Fe2O3@NiO also remained unchanged after the photocatalytic reaction, as confirmed by X-ray photoelectron spectroscopy (XPS).