Preparation of nano-silver-supported activated carbon using different ligands

Abstract

In this study, we investigated the effect of water soluble ligands [i.e., sodium borohydride (NaBH 4 ), polyvinyl alcohol, glucose and galactose] on the preparation of nano-silver-supported activated carbon (AC). Ligand-stabilized Ag nanoparticle dispersion characteristics were also compared with those of ligand-free Ag nanoparticles. The nanoparticle distribution was investigated using a scanning electron microscope (SEM) which enabled a qualitative analysis of ligand-dependent nanoparticle adsorption onto AC. Silver nanoparticles with average sizes ranging from 7 to 20 nm were synthesized with different coatings. In particular, silver nanoparticles reduced and stabilized by NaBH 4 were found to have a dense and homogenous dispersion of sizes in the range of 100-400 nm on the AC surface. These particles also seemed to remain on the AC surface after rinsing with water. The distribution of silver nanoparticles prepared in the presence of NaBH 4 /PVA was not as good as the one prepared with NaBH 4 . Their aggregate size varied from 300 to 600 nm on the AC surface and particles greater than 500 nm were eliminated from the AC surface upon rinsing with water. Glucose-and galactose-stabilized silver nanoparticles did not display an extensive adsorption and their adsorption seemed to be poor. However, glucose-stabilized silver nanoparticles could still be detectable to some extent after rinsing, while galactose-stabilized ones could not. Antimicrobial studies showed that all silver-containing carbons studied in this study inhibit bacterial growth and act as bacteriostatic agents.

Green Synthesis of an Activated Carbon-Supported Ag and ZnO Nanocomposite for Photocatalytic Degradation and Its Antibacterial Activities

“…This rough surface can be easily occupied by AgNPs and ZnONPs. Furthermore, the phenolic, lactonic and carboxylic functional groups of the AC are capable of having physical interactions with the prepared nanoparticles via stabilizing ligands [2]. The AgNPs on AC surface in sample Ag/AC are spherical with an average diameter around 20 nm with some aggregation and good dispersion on the surface as shown in Figure 6c The ZnO/Ag/AC sample formed spherical and flakes like particles with a high degree of aggregation.…”

“…Furthermore, the reduction and stabilization of the nanoparticles were achieved by using neem leaf extract as a reducing and capping agent. Accordingly, the need for reducing and stabilizing chemicals was eliminated [2,44]. Also, the application of the developed nanocomposites in catalytic reduction of 4-nitrophenol into useful 4-aminophenol is considered as a green process since it does not require any organic solvent [24].…”

“…Activated carbon in its bare form supports the growth of bacteria due to its biocompatibility. Activated carbon with antibacterial activity can be produced by impregnation of silver nanoparticles [2][3][4][5][6], or metallic oxides such as ZnO [7]. Furthermore, silver and ZnO nanoparticles supported on activated carbon have gained much attention for adsorption [6,[8][9][10][11][12][13][14][15][16], and catalytic applications [7,[17][18][19][20][21][22].…”

Recent Progress in Rapid Sintering of Nanosilver for Electronics Applications

“…Therefore, nanosilver particles (less than 20 nm) are traditionally precipitated from the silver salt solution by chemical reduction. Briefly, reducing agents such as Ascorbic Acid [ 83 ], Monohydrate Hydrazine [ 84 ], Sodium Citrate [ 85 ], Dehydrate Sodium Citrate [ 21 , 86 ], Polyvinyl Pyrrolidone [ 87 , 88 , 89 ], Ethylene Diamine Tetraacetic Acid [ 90 , 91 , 92 ], Sodium Sulfite [ 54 , 93 ] or Sodium Borohydride [ 57 , 94 ] are added to the silver salt solution, for instance, Silver Nitrate [ 95 , 96 ], Silver Chloride [ 97 , 98 ] or Silver Ammonia Solution [ 99 , 100 ], and then the chemical reduction reaction will occur in a polar solvent such as Ethanol [ 101 , 102 ], Methanol [ 103 , 104 ] or Tetrahydrofuran [ 105 , 106 ]. Finally, the nanoparticles and the solution are separated by the centrifugal method [ 107 ].…”

Interface Circuits for Microsensor Integrated Systems

“…Therefore, nanosilver particles (less than 20 nm) are traditionally precipitated from the silver salt solution by chemical reduction. Briefly, reducing agents such as Ascorbic Acid [83], Monohydrate Hydrazine [84], Sodium Citrate [85], Dehydrate Sodium Citrate [21,86], Polyvinyl Pyrrolidone [87][88][89], Ethylene Diamine Tetraacetic Acid [90][91][92], Sodium Sulfite [54,93] or Sodium Borohydride [57,94] are added to the silver salt solution, for instance, Silver Nitrate [95,96], Silver Chloride [97,98] or Silver Ammonia Solution [99,100], and then the chemical reduction reaction will occur in a polar solvent such as Ethanol [101,102], Methanol [103,104] or Tetrahydrofuran [105,106]. Finally, the nanoparticles and the solution are separated by the centrifugal method [107].…”