2007, Vol.8, No.3

Carbon Letters 2023 KCI Impact Factor : 1.35 KCI-WoS Impact Factor : 6.04

pISSN : 1976-4251 / eISSN : 2233-4998
https://journal.kci.go.kr/carbon

TiO2/ACF composites were prepared by the electrochemical method with Titanium (IV) n-butoxide (TNB) electrolyteunder diferent electrochemical opera 2/ACF composites decrease with the increase ofelectrochemical operation time. There is a single crystal structure which is anatase in all of the samples from the data of XRD.The SEM micrphotographs of TiO2/ACF composites show that the TiO2 particles were well mixed with the ACF. There are Oand P with strong C and Ti peaks in all samples from EDX results, and it also shows that a decrease of the C content with aincreasing of Ti content with increasing of the electrochemical operation time in the over all composites. DSC cures show thatthe exothermic peak of all composites at 560oC represents the transformation heat of amorphous parts to anatase phase and thediscontinuous grain growth of the transformed anatase particles. Finally, the excellent photoactivity of TiO2/ACF composites(especially, ACFT10) could be attributed that the decrease of concentration of MB can be concluded to be much faster for theadsorption by ACF than for photocatalytic decomposition by TiO2.

Carbon Nano Tubes could be either metallic or semi-conducting in nature, depending on their diameter. Its photocatalyticbehavior has given an impetus to use it as an anti-microbial agent. More than 95% Escherichia coli and Staphylococcusaureus bacteria got killed when exposed to Carbon Nano Tubes for 30 minutes in presence of sunlight. Carbon Nano Tubesare supposed to have smooth surface on to which it accumulates positive charges when exposed to light. The surface that isnon illuminated has negative charge. At the cellular level microorganisms produce negative charges on the cell membrane,Therefore damaging effect of multi walled carbon nano tubes (exposed to light) on the microorganisms is possible. In thispaper, photo catalytic killing of microbes by multi walled carbon nano tubes is reported. Killing was due to damage in the cellmembrane, as seen in SEM micrographs. Moreover biochemical analysis of membrane as well as total cellular proteins bySDS PAGE showed that there was denaturation of membrane proteins as well as total proteins of both the microbes studied.number of protein bands (i.e. due to breaking down of proteins) also showed anincrease in level of free amino acids in microbes. This further confirmed that proteins got denatured or broken down intoshorter units of amino acids. Increased level of free amino acids was recorded in both the microbes treated with multi walledcarbon nano tubes and sunlight.

Recent studies have revealed the poisonous nature of aluminum(III) species to aquatic and terrestrial organisms. Therefore,this investigation aims to develop batch adsorption experiments in the laboratory, aiming to the removal of aluminum(III)from aqueous solutions onto powdered activated carbon (PAC). The latter (which is an effective and inexpensive sorbent) wasprepared from olive stones generated as plant wastes and modified with an aqueous modifying oxidizing agent, viz. HNO3.The main parameters (i.e. initial solution pH, sorbent and Al3+ ions concentrations, stirring times and temperature) influencingthe sorption process were examined. The results obtained revealed that the sorption of Al3+ ions onto PAC is endothermic inRadushkevich (D-R) adsorption models over the concentration range studied. Under the optimum experimental conditionsemployed, the removal of ca. 100% Al3+ ions in the concentration range 1.35-2.75 mgl1 was attained. Moreover, theprocedure was successfully applied to the recovery of aluminum spiked to some environmental water samples with an RSD(%), does not exceed 1.22%.