Photoelectrochemical and photocatalytic detoxification of Cr(VI) to Cr(III) over terpyridine-derivatized Au nanoparticles on carbon paper and indium-tin-oxide electrodes
CHEMICAL ENGINEERING JOURNAL
Authors: Yi, Jae Moon; Kim, Tae Jun; Park, So Jeong; Hong, Sung-Min; Kang, Jun-Gill; Rhee, Choong Kyun; Kim, Jongwon; Sohn, Youngku
Abstract
Detoxification of hexavalent chromium (Cr(VI)) in the environment and development of corresponding new materials and detoxification protocols have actively been studied and applied. Herein, 2,2':6',2 ''-terpyridine-4'-thiol (STpy) was functionalized on Au nanoparticle (NP)-loaded carbon paper (CP) and indium-fin-oxide (ITO) electrodes (CP-AuNP and ITO-AuNP, respectively), and the photoelectrochemical (PEC) and photocatalytic detoxification of Cr(VI) using the resulting electrodes was investigated by cyclic voltammetry. Density functional theory at the B3LYP/6-31G level was used for geometry optimization, and the electronic energy state calculation was conducted at the TD-SCF/DFT/B3LYP level. For bare CP, ITO, and STpy-modified AuNP electrodes, the reduction potentials of Cr(VI) were around +0.3, -0.2 V, and +0.5 V (vs. Ag/AgCl), respectively. The PEC and photocatalytic Cr(VI) reduction performance of CP-AuNP was significantly improved upon STpy functionalization. Thus, these newly developed functionalized systems can provide very useful information for further improving the detoxification performances for various hazardous metals.
Core-satellite assemblies of Au@polydopamine@Ag nanoparticles for photothermal-mediated catalytic reaction
SOFT MATTER
Authors: Zakia, Maulida; Yoo, Seong Il
Abstract
Engineering plasmonic nanoparticles (NPs) into superstructures comprising two or more distinctive materials is highly desirable because these assemblies can unfold new properties that differ from those exhibited by their individual counterparts. In addition, metal NPs such as Au NPs and Ag NPs have played a major role in environmental remediation. In this study, we designed a heterogeneous NP assembly composed of an Au core and Ag satellite by utilizing a mussel-inspired polydopamine (PDA) strategy. This approach afforded substantial enhancement in the catalytic activity because of the synergistic effect between the Au core and Ag satellite. Specifically, the heat from the localized surface plasmon resonance excitation of the Au NPs can accelerate the reduction reaction of 4-nitrophenol, while the Ag NPs act as a catalyst for reducing the activation energy. Overall, we prepared a facile route to produce heterogeneous metal NP assemblies, which offers promise in scalable synthesis and application in heterogeneous catalysis.