title: Gold nanorod@iron oxide core-shell heterostructures: synthesis, characterization, and photocatalytic performance.
abstract: Iron oxides are directly coated on the surface of cetyl-trimethylammonium bromide (CTAB)-capped gold nanorods (AuNRs) in aqueous solutions at room temperature, which results in AuNR@Fe2O3, AuNR@Fe3O4, and AuNR@Fe2O3@Fe3O4core-shell heterostructures. The iron oxide shells are uniform, smooth, with characteristic porous structure, and their thickness can be readily tuned. The shell formation is highly dependent on the reaction parameters including pH and CTAB concentration. The Fe2O3shell is amorphous and exhibits nearly zero remanence and coercivity, while the Fe3O4shell is ferromagnetic with a low saturation magnetization of about 0.5 emu g-1due to its low crystallinity and the porous structure. At elevated temperatures achieved by plasmonic heating of the Au core, the Fe2O3shell transforms from amorphous to γ-Fe2O3and α-Fe2O3phases, while the Fe3O4phase disappears because of the oxidation of Fe2+. A 1.4-fold increase of photocatalytic performance is observed due to the plasmonic resonance provided by the Au core. The photocatalytic efficiency of Fe3O4is about 1.7-fold higher than Fe2O3as more surface defects are present on the Fe3O4shell, promoting the adsorption and activation of reagents on the surface during the catalytic reactions. This approach can be readily extended to other nanostructures including Au spherical nanoparticles and nanostars. These highly uniform and multifunctional core-shell heterostructures can be of great potential in a variety of energy, magnetic, and environment applications.
authors.affiliation: Department of Chemistry, College of Sciences, Shanghai University, Shanghai, 200444, China and Division of i-Lab, Suzhou Institute of Nano-Tech & Nano-Bionics, Chinese Academy of Sciences, Suzhou, Jiangsu 215123, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Li
authors.affiliation: Division of i-Lab, Suzhou Institute of Nano-Tech & Nano-Bionics, Chinese Academy of Sciences, Suzhou, Jiangsu 215123, China and Materials Science and Engineering School, Luoyang Institute of Science and Technology, Luoyang, Henan 471023, China.
authors.forename: Junwei
authors.initials: J
authors.lastname: Zhao
authors.affiliation: College of Physics, Optoelectronics and Energy & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou, Jiangsu 215006, China. niweihai@suda.edu.cn.
authors.forename: Wenlong
authors.initials: W
authors.lastname: You
authors.affiliation: Department of Chemistry, College of Sciences, Shanghai University, Shanghai, 200444, China.
authors.forename: Danhong
authors.initials: D
authors.lastname: Cheng
authors.affiliation: Division of i-Lab, Suzhou Institute of Nano-Tech & Nano-Bionics, Chinese Academy of Sciences, Suzhou, Jiangsu 215123, China and College of Physics, Optoelectronics and Energy & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou, Jiangsu 215006, China. niweihai@suda.edu.cn.
authors.forename: Weihai
authors.identifier: http://orcid.org/0000-0002-6320-7717
authors.initials: W
authors.lastname: Ni