Graphene Oxide/α‐Bi2O3 Composites for Visible‐Light Photocatalysis, Chemical Catalysis, and Solar Energy Conversion. Issue 3 (27th February 2014)

• Record Type: Journal Article
• Authors: Som, Tirtha; Troppenz, Gerald V.; Wendt, R. Robert; Wollgarten, Markus; Rappich, Jörg; Emmerling, Franziska; Rademann, Klaus
• Is Part Of: ChemSusChem. Volume 7:Issue 3(2014:Mar.)
• Page Start: 854
• Page End: 865
• Publication Date: 2014-02-27
• Subjects: Green chemistry -- Periodicals; Sustainable engineering -- Periodicals; Chemistry -- Periodicals; Chemical engineering -- Periodicals; 660
• DOI: 10.1002/cssc.201300990
• Languages: English
• ISSNs: 1864-5631

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>The growing challenges of environmental purification by solar photocatalysis, precious‐metal‐free catalysis, and photocurrent generation in photovoltaic cells receive the utmost global attention. Here we demonstrate a one‐pot, green chemical synthesis of a new stable heterostructured, ecofriendly, multifunctional microcomposite that consists of α‐Bi<sub>2</sub>O<sub>3</sub> microneedles intercalated with anchored graphene oxide (GO) microsheets (1.0 wt %) for the above‐mentioned applications on a large economical scale. The bare α‐Bi<sub>2</sub>O<sub>3</sub> microneedles display two times better photocatalytic activities than commercial TiO<sub>2</sub> (Degussa‐P25), whereas the GO‐hybridized composite exhibits approximately four to six times enhanced photocatalytic activities than the neat TiO<sub>2</sub> photocatalyst in the degradation of colored aromatic organic dyes (crystal violet and rhodamine 6G) under visible‐light irradiation (300 W tungsten lamp). The highly efficient activity is associated with the strong surface adsorption ability of GO for aromatic dye molecules, the high carrier acceptability, and the efficient electron–hole pair separation in Bi<sub>2</sub>O<sub>3</sub> by individual adjoining GO sheets. The introduction of Ag nanoparticles (2.0 wt %) further enhances the photocatalytic performance of the composite over eightfold because of a plasmon‐induced electron‐transfer process from Ag nanoparticles through the GO sheets into the conduction band of Bi<sub>2</sub>O<sub>3</sub>. The new composites are also catalytically active and catalyze the reduction of 4‐nitrophenol to 4‐aminophenol in the presence of borohydride ions. Photoanodes assembled from GO/α‐Bi<sub>2</sub>O<sub>3</sub> and Ag/GO/α‐Bi<sub>2</sub>O<sub>3</sub> composites display an improved photocurrent response (power conversion efficiency ∼20 % higher) over those prepared without GO in dye‐sensitized solar cells.</p> </abstract>