Supported noble metal nanoparticles as photo/sono-catalysts for synthesis of chemicals and degradation of pollutants

Abstract

This review summarizes the utilization of supported noble metal nanoparticles (such as Au/TiO 2 , Au/ZrO 2 , Ag/AgCl) as efficient photo/sono-catalysts for the selective synthesis of chemicals and degradation of environmental pollutants. Supported noble metal nanoparticles could efficiently catalyze the conversion of solar energy into chemical energy. Under UV/visible light irradiation, important chemical transformations such as the oxidation of alcohols to carbonyl compounds, the oxidation of thiol to disulfide, the oxidation of benzene to phenol, and the reduction of nitroaromatic compounds to form aromatic azo compounds, are effectively achieved by supported noble metal nanoparticles. Under ultrasound irradiation, supported noble metal nanoparticles could efficiently catalyze the production of hydrogen from water. Moreover, various pollutants, including aldehydes, alcohols, acids, phenolic compounds, and dyes, can be effectively decomposed over supported noble metal nanoparticles under UV/visible light irradiation. Under ultrasound irradiation, pollutant molecules can also be completely degraded with supported noble metal nanoparticles as catalysts.noble metal nanoparticles, photocatalyst, sonocatalyst

Utilization of the Terrestrial Weed Guduchi (Tinospora cordifolia) in Clean-Green Synthesis of Gold Nanoparticles

“…On closer examination, the spectrum of gold nanoparticles shows bands at 1643 and 1521 cm -1 (due to N-H bond) confirming the presence of amines. As presence of alkaloids in T. cordifolia stem has been reported, [26][27][28] it is possible that the amino groups are a part of those alkaloids.…”

TiO2 Crystal Form-Dependence of the Au/TiO2 Plasmon Photocatalyst’s Activity

“…On the other hand, Au NP strongly absorbs visible light because of the localized surface plasmon resonance (LSPR) derived from the collective oscillation of conductive electrons. − The LSPR enhanced strong local electric field near the particle surface gives rise to the surface-enhanced Raman scattering and infrared absorption effects. , The LSPR induced strong local electric field also increases the activity of the semiconductor photocatalysts and the efficiency of the dye-sensitized solar cells. − The visible-light excitation of the LSPR of Au/TiO 2 causes the IET from Au to TiO 2 of which direction is opposite to that of the UV-light-induced IET. , This discovery has led to the development of LSPR driven photocatalysts or plasmon photocatalysts represented by Au/TiO 2 . This new type of photocatalyst exhibits activities for the oxidations as organic synthesis besides water splitting and degradation of the organic pollutants. − So far, the oxidations of isopropanol to acetone, , thiol to disulfide, and benzene to phenol , have been reported. The oxidation of alcohol to aldehyde is one of the key reactions in the organic synthesis, and the development of the green processes using O 2 as an oxidizing agent is highly desired.…”

Merging Metallic Catalysts and Sonication: A Periodic Table Overview

“…In line with the above-mentioned applications, a 2011 review by Wen et al detailed the use of supported noble metal NPs (Au/TiO 2 , Au/ZrO 2 , Ag/AgCl) as efficient catalysts for selective chemical syntheses and degradation of environmental pollutants [103]. Thus, the NPs could effectively catalyze solar-energy conversion into chemical energy (i.e., oxidation of alcohols, thiols, and benzene into carbonyls, disulfides, and phenol, respectively, or the reduction of nitro-aromatic compounds to the corresponding azo derivatives).…”