To promote efficient use of solar energy, many studies have focused on the modification of TiO2 to extend its spectral response to visible region. Here we report a combined modification of TiO2 by two components: the nonmetal element boron and the metal oxide Ni2O3. The photocatalyst presents high photocatalytic activity in the visible region, which can efficiently degrade and mineralize toxic organic pollutants such as trichlorophenol (TCP), 2,4-dichlorophenol (2,4-DCP), and sodium benzoate. The dechlorination and mineralization results indicate the photocatalytic pathway via visible light excitation. The study demonstrates that the modification of TiO2 both to extend its spectral response to the visible region and to improve its catalytic efficiency can be achieved by doping with boron, a nonmetal, and Ni2O3, a metal oxide.

The photooxidative degradation of sulforhodamine-B dye (SRB) taking place in visible-light illuminated platinized titania dispersions is revisited to examine the influence of metallic platinum doped on TiO 2 particles (Degussa P25 titania) by photocatalytic deposition from a hexachloroplatinic acid solution. The various TiO 2 / Pt specimens were characterized by transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy (XPS). The self-photosensitized degradation of SRB mediated by TiO 2 /Pt specimens is 3-fold faster than that occurring on TiO 2 alone under visible light irradiation and under otherwise identical conditions. That is, the TiO 2 /Pt system exhibited greater catalytic activity than P25 TiO 2 alone, which earlier proved to be an effective photocatalyst in the degradation of dyes under visible illumination. A reaction mechanism is proposed on the basis of a series of experiments that included spintrap electron spin resonance (ESR) spectral results, measurement of quantities of H 2 O 2 formed, chemical oxygen demand (COD Cr ), and total organic carbon (TOC) data. The platinum dopant acts as an electron sink from which molecular oxygen scavenges the electrons to yield superoxide radical anions (O 2 -• ) first and then • OH radicals, which are known to cause the ultimate self-destruction of the SRB dye.

A series of 2,6-dibenzhydryl-N-(2-phenyliminoacenaphthylenylidene)-4-methylbenzenamines ( L1 - L5 ) and the nickel(II) dibromide complexes thereof ( C1 - C5 ) were synthesized and fully characterized. The molecular structures of representative complexes were determined by single-crystal X-ray diffraction and revealed a distorted-pyramidal geometry at nickel. All nickel(II) procatalysts exhibited very high activity for the polymerization of ethylene, with activities as high as the range of 107 g of PE (mol of Ni)-1 h-1