Photocatalytic and Photoelectrocatalytic Degradation of Methyl Orange Using Graphite/PbTiO₃ Composite

Abstract

Synthesis of graphite/PbTiO3 composite as a catalyst in photodegradation and photoelectrodegradation process of methyl orange have been conducted. The purposes of this research are to study the effect of radiation time, composition of composite, voltage and pH of solution for methyl orange degradation. Photodegradation process of methyl orange was carried out for 5; 10; 15; 20; 25 and 30 min. Ratio of graphite : PbTiO3 (w/w) were varied at 1:3; 1:2; 1:1; 2:1 and 3:1. Meanwhile, the applied voltages were 7.5; 10 and 12.5 V and the photoelectrodegradation was conducted under pH condition of 3; 7; and 11, respectively. The result showed that optimum composition of graphite/PbTiO3 in the methyl orange photodegradation was obtained at 1:1 ratio for 30 min with degradation up to 90.43% ± 0.062. The degradation reaction follows first order reaction with a rate constant of 0.0688 min-1. The optimum voltage is 10 V, in which it reduced the methyl orange concentration up to 92.65% ± 0 with a rate constant 0.0941 min-1 for first order reaction. The optimum pH is pH = 11, that provide methyl orange reduction up to 95.28% ± 0.082.

Methyl Violet Degradation Using Photocatalytic and Photoelectrocatalytic Processes Over Graphite/PbTiO3 Composite

“…Based on our previous report [10], the graphite/PbTiO3 diffractograms outlined in Figure 4 showed that the composites constructed with graphite/ PbTiO3 ratio 1/1 having highest crystallinity than other composition. The addition of graphite with high concentration decreased the composites crystallinity due to the amorphous phase of graphite dominating in the system.…”

“…OH· + substrat (dye) → product (10) Based on this result, the optimum photodegradation of methyl violet was achieved at Graphite/PbTiO3 ratio 1/1 up to 92.20 %.…”

“…Synthesis of PbTiO3 was performed by combining sol-gel method on the TiO2 synthesis according to previous research [9,10] and directly added with Pb(NO3)2 after achieving TiO2 sol-gel phase. The produced PbTiO3 compounds was in the form of yellow powder.…”

Synthesis, Characterization and Catalytic Activity of NiO-CoO-MgO Nano-Composite Catalyst

“…From these results it can be seen that, the decolorization efficiency of CBB dye increased in acidic media because of the attraction force between the anionic groups of dye and decreased in basic media because of the repulsion force between the anionic groups of the dye with negative charge of the catalyst surface reached to 46.4% at pH = 9 [22][23][24]. The increasing of pH values cause a decrease of catalytic activity of the prepared catalyst because of the increasing rate of recombination between (e − /h + ) pairs of the reaction mixture [25][26].…”

Removal of Hazardous Brilliant Cresyl Blue Dye Utilizing Aluminum Oxide as Photocatalyst

“…This maximum of photocatalytic efficiency was caused by the produce the hydroxyl radical which is generated from oxidizing hydroxyl ions. On the other hand, increases absorption of brilliant cresyl blue tincture on the surface of aluminum oxide, the pH > = 10, in alkaline medium, Fig 7. The change of (A/A0)with irradiation time at various temperature for photocatalytic destroy an average of bright cresyl blue by using solar energy, initial brilliant cresyl blue stain concentrations = 50 ppm, amount of photocatalyst aluminum oxide = 0.17 g/100 cm 3 and PH = 10 photocatalytic degradation of brilliant cresyl blue dye has been gradually decreasing due to the reduction of the brilliant cresyl blue stain that was absorbed on the negative charge surface aluminum oxide as well as at high pH values of hydroxyl radicals are so rapidly scavenged [16].…”