Printer Friendly

Effects of synthesis Ni doped Ti[O.sub.2] on photocatalytic degradation process.

INTRODUCTION

In several years, various kinds of organic pollutants to be decomposed by using Ti[O.sub.2] nanoparticles extensively because Ti[O.sub.2] particles had a lot of efficiency of high oxidative power, non-toxicity, photostability and water insoluble properties under most conditions [10]. Moreover, Ti[O.sub.2] photocatalysts were low prices, chemical stability and no toxicity and which can be completely declorization and immobilization of many toxic organic pollutants [8]. Ti[O.sub.2] modification has been justified to various kinds of approaches by metal-ion doped Ti[O.sub.2] and non-metal doped-Ti[O.sub.2]. By using transition metal for metal-ion doped-Ti[O.sub.2] are Cu, Co, Ni, Cr, Mn, Mo, Nb, V, Fe, Ru, Au, Ag and Pt and non-metal doped-Ti[O.sub.2] are N, S, C, B, P, I and F [1]. A transition metalion of doped-Ti[O.sub.2] has been experiment by improving photocatalytic activity of semiconductor oxides [3].

Nickel is one of transition elements used to modify the titania surface. The effects of [Ni.sup.2+] on the photocatalytic properties of Ti[O.sub.2] have been investigated by several authors [7]. More importantly, the existence of [Ni.sup.2+] greatly suppressed recombination of electron-hole pairs on the surface of the photocatalyst [6]. On the other hand, low valence [Ni.sup.2+] ion dopant improves the photocatalytic activity of certain semiconductor photocatalyst [5,9]. However, the photocatalytic activity of the prepared metal-doped Ti[O.sub.2] photocatalysts depends strongly on the species and concentration of the dopant ion [11]. Ti[O.sub.2] mediated heterogeneous photocatalysis conducted potentially advantages by improving ambient conditions and many organic pollutants of harmless products of C[O.sub.2], [H.sub.2]O and mineral acids by perfect mineralization [4]. In this study is to decolorized azo dyes by different volume amount of doped-Ti[O.sub.2] and compare the effects of this photocatalysts under sunlight irradiation.

MATERIALS AND METHODS

Chemicals:

Titanium isopropoxide (Ti[(O[C.sub.3][H.sub.7]).sub.4]), ethanol([C.sub.2][H.sub.5]OH), acetic acid(C[H.sub.3]COOH), nickel chloride hexahydrate (Ni[Cl.sub.2].6[H.sub.2]O) and Acid orange 7 ([C.sub.16][H.sub.11][N.sub.2]Na[O.sub.4]S) were purchased.

Synthesis method:

The doped Ti[O.sub.2] photocatalysts were prepared by calcination of synthesis Ti[O.sub.2] product with nickel chloride hexahydrate (Ni[Cl.sub.2].6[H.sub.2]O) as precursor for Ni-doped Ti[O.sub.2]. 10ml Ti[(O[C.sub.3][H.sub.7]).sub.4] and 17ml C2H5OH are mixed and stirring well. After one hour, 1ml of distilled water was added drop by drop into this solution. 20ml volume ratio of 0.5 mole precursor was added at three hour of synthesis solution and continues stirring one hour by vigorously. And then, 1.7ml of C[H.sub.3]COOH is added and 1min stirred with this solution. Moreover, the solution is changed and reflux three hours for becomes sol-gel type. After reflux time, the sol-gel are filtered and dried in oven at 70C for 24 hour. Finally, the doped Ti[O.sub.2] catalyst particles were obtained through calcination in a muffle furnace at 500C for 2 hr.

Photocatalytic procedure:

The photocatalytic degradation experiments of 30mg/l AO7 solutions were investigated in under sunlight irradiation in 0.3g of synthesis and doped Ti[O.sub.2] suspensions. The 500ml of AO7 solutions were prepared from stock solution by dilution with ultra-pure water. The experiments are done for 6 hour and 20ml of water samples were collected at 0, 0.5, 1, 1.5, 2, 3, 4, 5 and 6 hr. To obtain the clear water samples by using 0.45 m membrane filter paper was used for collecting all samples to remove the synthesis Ti[O.sub.2] and synthesis doped Ti[O.sub.2] particles.

RESULTS AND DISCUSSION

SEM analysis obtained results:

Figure 1 (a) and (b) shown scanning electron microscopy observation of synthesis Ti[O.sub.2] and Ni-doped Ti[O.sub.2] powders. The aggregate formed by the emulsifantgelation technology has an average size in the range of 1 [micro]m. And then the aggregate has a spherical shape with an average diameter of around 200 to 300 nm can be observed for both synthesis powders.

Photocatalytic activity of AO7 on Ni- doped-Ti[O.sub.2] suspensions:

Figure 2 illustrated that the effect of photocatalytic degradation activity of 30mg/l Acid Orange 7 by synthesis Ti[O.sub.2] and Ni-doped Ti[O.sub.2] suspensions. In this results, more adsorption efficiency in nickel doped Ti[O.sub.2] compared with synthesis Ti[O.sub.2]. The photodegradation percent of synthesis Ti[O.sub.2] and Ni-doped Ti[O.sub.2] are 58% and 66%, respectively. Moreover, [Ni.sup.2+] activated an important role in trapping the electrons and helps in charge separation, therefore photocatalytic activity is comparatively good.

Kinetics analysis for the photocatalytic degradation of single and binary azo dye solutions:

Table 1 was shown the [k.sub.app] values for the photocatalytic degradation of synthesis Ti[O.sub.2] and Ni-doped Ti[O.sub.2] powders. The Langmuir-Hinshelwood model mentioned equivalent to concern with the pseudo first-order kinetics of photocatalytic degradation of basic azo dyes [2]. The [k.sub.app] value for synthesis Ti[O.sub.2] and Ni-doped Ti[O.sub.2] were 0.0024 and 0.0025 respectively. Therefore, the value of synthesis Ni-doped Ti[O.sub.2] is larger than that of synthesis Ti[O.sub.2] under approximate conditions. The [R.sup.2] of synthesis Ti[O.sub.2] is 0.8275 and Ni-doped Ti[O.sub.2] is 0.9975.

Conclusion:

Both synthesis powders have spherical shape and average size are around 200-300nm. But the color removal percentage of Ni-doped Ti[O.sub.2] is more than synthesis Ti[O.sub.2] in photocatalytic degradation process. And then, the kinetics value of Ni-doped Ti[O.sub.2] is also larger than synthesis Ti[O.sub.2].

ARTICLE INFO

Article history:

Received 25 March 2014

Received in revised form 20 April 2014

Accepted 15 May 2014

Available online 5 June 2014

REFERENCES

[1] Adriana Zaleska, 2008. Doped-Ti[O.sub.2]: A Review, Recent Patents on Engineering.

[2] Gozmen, B., M. Turabik and A. Hesenov, 2008. Photocatalytic degradation of basic red 46 and basic yellow 28 in single and binary mixture by UV/Ti[O.sub.2] /periodate system, J. Hazard. Mater.

[3] Jose, A.A., Navo Ao, Juan J. Testa, Pablo Djedjeian, Javier R. Padro An, Diana Rodro Aguez and Marta I. Litter, 1999. Iron-doped titania powders prepared by a sol [+ or -] gel method. Part II: Photocatalytic properties, Applied Catalysis A: General.

[4] Jianhui Sun, Liping Qiao, Shengpeng Sun and Guoliang Wang, 2008. Photocatalytic degradation of Orange G on nitrogen-doped Ti[O.sub.2] catalysts under visible light and sunlight irradiation, Journal of Hazardous Materials.

[5] Kudo and Sekizawa, 2000. Chem. Commun.

[6] Noor Shahina Begum, H.M. Farveez Ahmed and K.R. Gunashekar, et al., 2008. Prasetyo Hermawan, Harno Dwi Pranowo and Indriana Kartini (2011). PHYSICAL CHARACTERIZATION OF Ni(II) DOPED Ti[O.sub.2] NANOCRYSTAL BY SOL-GEL PROCESS, Indo. J. Chem.

[7] Peerakiatkhajohn, P., W. Onreabroy, C. Chawengkijwanich and S. Chiarakorn, 2011. Preparation of Visible-Light-Responsive Ti[O.sub.2] Doped Ag Thin Film on PET Plastic for BTEX Treatment, Journal of Sustainable Energy and Environment.

[8] Sreethawong, Suzuki Y. and Yoshikawa, 2005. Int. J. Hydrogen Energy.

[9] Thanh Binh Nguyen, Moon-Jin Hwang and Kwang-Sun Ryu, 2012. Synthesis and High Photocatalytic Activity of Zn-doped Ti[O.sub.2] Nanoparticles by Sol-gel and Ammonia-Evaporation Method, Bull. Korean Chem. Soc.

[10] Wei-Yu Ho, Mu-Hsuan Chan, Kao-Shan Yao, Chi-Lung Chang, Da-Yung Wang and Cheng-Hsun Hsu, 2008. Characteristics of chromium-doped titanium oxide coatings synthesized by cathodic arc deposition, Thin Solid Films.

Corresponding Author: Ohm Mar Min, School of Environmental Engineering, University Malaysia Perlis, 02600 Arau, Perlis

E-mail: ohmohm84@gmail.com

(1) Ohm Mar Min, (1) Soon-An Ong, (1) Yee-Shian Wong, (2) Li-Ngee Ho

(1) School of Environmental Engineering, University Malaysia Perlis, 02600 Arau, Perlis

(2) School of Material Engineering, University Malaysia Perlis, 02600 Arau, Perlis

Table 1: Values of [k.sub.app] for the photodegradation
degradation of 30mg-l AO7 by synthesis Ti[O.sub.2] and
Ni-doped Ti[O.sub.2] suspensions.

Synthesis Ti[O.sub.2]       Synthesis Ni-doped Ti[O.sub.2]

[k.sub.app]    [R.sup.2]    [k.sub.app]    [R.sup.2]

0.0024           0.8297        0.0025        0.9975
COPYRIGHT 2014 American-Eurasian Network for Scientific Information
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2014 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Author:Min, Ohm Mar; Ong, Soon-An; Wong, Yee-Shian; Ho, Li-Ngee
Publication:Advances in Environmental Biology
Article Type:Report
Date:Jun 20, 2014
Words:1435
Previous Article:An integrated approach in entrepreneurship education using MAIR framework.
Next Article:Factors influencing the diffusion & implementation of management accounting innovations (MAIS), Malaysian manufacturing industries in Nothern Region.
Topics:

Terms of use | Privacy policy | Copyright © 2019 Farlex, Inc. | Feedback | For webmasters