The effect of pH on the photocatalytic degradation of cationic and anionic dyes using polyazomethine/ZnO and polyazomethine/TiO2 nanocomposites

Sampath Krishnan,Keerthika Kumarasamy,Mei-Ching Lin,Anusha Karunakaran,Pradeeba Shanmugam Jaiganesh

doi:10.6703/ijase.202109_18(5).008

Abstract

ABSTRACT Advanced oxidation process (AOP) is a recently developed by the researchers for the wastewater treatment over a decade which has more advantages when compared with other conventional methods. Photocatalysis is the most efficient and attractive techniques for the degradation of organic pollutant using semiconductor nanostructured material in presence of solar energy. The researchers decided on the rising deprivation rate of pollutants by incorporating inorganic materials into conducting polymers to understand its synergistic and complementary behaviour among the polymer and inorganic materials. Based on this, the present study is to synthesize polymeric nanocomposite material ZnO with polyazomethine (PNZ) and TiO2 with polyazomethine (PNT) through ultrasonication technique. The synthesized polymeric nanocomposites were used for the photodegradation of cationic and anionic dyes. These synthesized polymeric nanocomposites can act as a potential alternate in future due to its enhanced dye degradation ability and higher stability nature. By varying pH of the dye solution at different time interval the degradation efficiency of photocalatystswere analyzed and found that cationic dyes are removed more when compared to anionic dyes.

Highlights

The Central Pollution Control Board (CPCB in India) has listed that the dyeing industries are the majorly contaminating bodies into the living environment
Advanced oxidation process (AOP) is a recently developed by the researchers for the wastewater treatment over a decade which has more advantages when compared with other conventional methods
The high pure chemicals were purchased from Sigma Aldrich, such as DMF (99.98%), acetone (99.98%), ZnO (99.98%), TiO2 (99.98%), methylene blue, malachite green, Bismarck brown, methyl orange and alizarin red S

Summary

INTRODUCTION

The Central Pollution Control Board (CPCB in India) has listed that the dyeing industries are the majorly contaminating bodies into the living environment. Major industries generally use these acidic and basic dyes for imparting colour to the finished products resulting in the release of toxic effluents during the end of the dyeing and finishing process. Djokic et al (2012) summarized that direct contact of this dye in eyes can cause edema, hyperemia, purulent, necrosis, sloughing of the corneal stratum and has a capability of causing the individual using this bismarck dyed fabrics These dyes are stable, non-biodegradable and highly soluble in nature. The following cationic dyes like methylene blue (MB), bismarck brown (BB) & malachite green (MG) and anionic dyes like methyl orange (MO) and alizarin red S (ARS) are selected for the present research study using polyazomethine/ZnO (PNZ) and polyazomethine/TiO2 nanocomposites (PNT)

MATERIALS AND METHODOLOGY

Mechanism of Photocatalytic Activity

Cationic Dyes Degradation

Anionic Dyes Degradation

CONCLUSION