Synthesis of Au-BiVO4 Nanocomposite through Anodic Electrodeposition Followed by Galvanic Replacement and Its Application to the Photocatalytic Decomposition of Methyl Orange

• Published in: Chemphyschem 2014-07, Vol.15 (10), p.2052-2057
• Main Authors: Myung, Noseung, Lee, Wooju, Lee, Changhyun, Jeong, Seonghan, Rajeshwar, Krishnan
• Format: Article
• Language: English
• Subjects: Alloys; Chemistry; Decomposition; Electrochemistry; Electrodeposition; electrosynthesis; Exact sciences and technology; General and physical chemistry; Nanocomposites; nanomaterials; oxide semiconductors; Photochemistry; photoelectrochemistry; Photoelectrochemistry. Electrochemiluminescence; Physical chemistry of induced reactions (with radiations, particles and ultrasonics); Study of interfaces; water splitting; Water treatment
• ISSN: 1439-4235; 1439-7641
• DOI: 10.1002/cphc.201402032

A Au‐BiVO4 nanocomposite is synthesized by a two‐step strategy involving anodic electrodeposition combined with in situ galvanic replacement. First, a BiVO4 layer is prepared by the anodic oxidation of pre‐electrodeposited Bi film in a VO43− containing electrolyte. Thus‐prepared BiVO4 film contains excess metallic Bi, which is then galvanically replaced with Au from an aqueous HAuCl4 solution, resulting in the Au‐BiVO4 composite in the second step. Optical, photoelectrochemical and photocatalytic properties are investigated by using X‐ray diffraction, energy‐dispersive X‐ray analysis, diffuse reflectance spectrometry, and photoelectrochemical analyses. The visible‐light photocatalytic activity of the Au‐BiVO4 composite is evaluated using the decomposition of methyl orange dye and is superior to the bare BiVO4 film counterpart. Bismuth vanadate and gold‐modified bismuth vanadate are synthesized for the first time by a two‐step anodic electrodeposition‐galvanic replacement hybrid scheme. The metal‐modified sample shows higher visible‐light absorption, higher anodic photocurrent, and superior photocatalytic activity relative to the virgin sample.