Article pubs.acs.org/JPCC
Preparation and Strongly Enhanced Visible Light Photocatalytic Activity of TiO2 Nanoparticles Modified by Conjugated Derivatives of Polyisoprene Qingzhi Luo,† Leilei Bao,‡ Desong Wang,*,† Xueyan Li,† and Jing An† †
School of Sciences and ‡College of Chemical and Pharmaceutical Engineering, Hebei University of Science and Technology, Shijiazhuang 050018, People’s Republic of China ABSTRACT: Conjugated polymer modification is one of the most promising methods for preparing TiO2-based visiblelight-responsive photocatalysts. In this article, TiO2 nanoparticles modified by conjugated derivatives of polyisoprene (CDPIP) were prepared from TiO2/polyisoprene nanocomposites by the bromine addition reaction of polyisoprene and dehydrobromination reaction of the brominated polyisoprene. The visible light photocatalytic activities of asprepared nanocomposites were evaluated using methyl orange as the model contaminant and two indoor fluorescent lamps with a 400 nm cutoff filter as the visible light source. TEM images show that a layer of CDPIP attaches on the surface of TiO2 nanoparticles. XPS, FTIR, and Raman spectra further reveal the conjugated structure of CDPIP. The results of XRD, UV−vis DRS, and PL spectra show that modification of CDPIP does not change the crystalline structure of TiO2, greatly improves the absorbance of the nanocomposites in the whole range of visible light, and obviously reduces the recombination probability of photogenerated electrons and holes. The photocatalytic experiments reveal that the CDPIP-modified TiO2 nanocomposites exhibit significantly higher photocatalytic activity than that of TiO2 (P-25) under visible light irradiation.
1. INTRODUCTION Photocatalysis, which is based on generation of reactive species using a semiconductor as the photocatalyst and can oxidize a broad range of organic pollutants quickly and nonselectively, has overwhelmingly prevailed as the subject of much research for environmental contaminants treatment.1 In this respect, TiO2 is widely regarded as the most promising semiconductor material owing to its excellent photodecomposition power, high stability, nontoxicity, inexpensiveness, and abundant resource.2−5 Unfortunately, TiO2 is a wide band gap (3.2 eV for the anatase phase) semiconductor and can be excited only by UV light irradiation (
