Enhanced Catalytic Activity of Gold Nanoparticles Doped in a Mesoporous Organic Gel Based on Polymeric Phloroglucinol Carboxylic Acid−Formaldehyde

Abstract

Gold nanoparticles were supported by a phloroglucinolcarboxylic acid-formaldehyde (PF) gel, a new organic gel with a 30 nm spheroid-like structure. The surface area of the PF gel with gold nanoparticles was 550 m(2)/g. Gold nanoparticles supported on a PF gel exhibited catalytic activity in the reduction of 4-nitrophenol with a reaction rate constant of 7.4 x 10(-3) s(-1), which is high in the reported heterogeneous reaction system. The adsorption behavior of 4-nitrophenol into the gel support was observed by ultraviolet-visible absorption spectroscopy. Gold nanoparticles in the PF network were characterized by scanning electron microscopy, atomic force microscopy, and transmission electron microscopy observation. The high reduction rate would be attributed to the extraction and diffusion of the reactant through the pores of a PF gel support to encounter the highly dispersed gold nanoparticles on the surface and inside the material.

Stimuli-responsive gels as reaction vessels and reusable catalysts

“…On the other hand, the removal of the liquid phase in this type of materials has been recently employed to prepare alginatebased metalloxerogels that can act as heterogeneous catalysts in the reduction of 4-nitrophenol. 72,73 Biocatalysis with biopolymer-based hydrogels. Enzymatic catalysis using encapsulated enzymes in recyclable biohydrogels beads has been also widely documented during the last decade.…”

Synthesis and assembly of gold nanoparticle-doped polymer solid foam films at the liquid/liquid interface and their catalytic properties

“…The reduction of 4-NP by sodium or potassium borohydride has been used extensively as a model reaction to evaluate the catalytic activities of gold nanoparticles [16,20,21,23,24,[66][67][68][69]. The catalytic reduction of 4-NP follows pseudo first-order rate kinetics with respect to the concentration of 4-NP when the concentration of the reductant is much greater than that of 4-NP.…”

“…8 also illustrates the relationship between ln(A t /A 0 ) and reaction time. The linear relation between these two variables indicates that the catalytic reduction of 4-NP followed pseudo first-order rate kinetics with respect to 4-NP concentration [21,23,24]. The rate constant of the reduction of 4-NP by the composite catalyst can be calculated from the slope of the fit line.…”

“…Compared with conventional supports such as metal oxides and active carbon, functionalized polymer-supported gold nanoparticles show higher catalytic activities [10] and have attracted much attention. Gold nanoparticles or clusters capped with polymers [18][19][20], those embedded in the shells of core-shell micelles formed by amphiphilic block copolymers [21] or those in porous microgels of polymers [22,23] have exhibited high catalytic activities. Porous structures are suitable for supporting catalytic nanoparticles because they not only act as templates to direct the formation of nanoparticles whose sizes can be limited by the pore size, but they also act as supports to immobilize and stabilize the formed nanoparticles.…”

Fabrication of disk-shaped, deuterated resorcinol/formaldehyde foam target for laser–plasma experiments

“…Fabrication of deuterated targets is also important for inertial fusion experiments. However, controlling their shape and density has proven to be difficult owing to their high reactivity at room temperature [22][23][24] . Recently, low-density targets, in the form of thin films and flat-surface targets, are being required for laser acceleration experiments whereas deuterated targets are useful for distinguishing the origin of the generated proton or deuteron ions.…”