Background: The cost of effluent treatment is not affordable by small scale
industries especially in developing countries. Hence the effluent is discharged without
treatment into water bodies. The dyes do not degrade easily and possess a major
concern to be addressed. The aquatic life is highly affected and also leads to bio
magnification of the chemicals through the food chain.
Objective: To synthesize a ternary hybrid structure for enhanced photocatalytic activity
under visible light. It is intended to reduce toxicity caused by dyeing units.
Methods: Synthesized nanomaterials are characterized and used as photocatlyst for the
degradation of methylene blue. In degradation experiment known weight of catalyst was
added to known volume of an aqueous solution of dye at various concentrations. The
solutions are aerated in dark for about 30 min. At the time of irradiation of light, known
aliquot of the aqueous mixture was collected at an interval of constant time each from the
reaction solution. The catalyst in the mixture was separated by centrifuging the mixture
and absorbance was measured. The % of degradation of the dye can be determined
knowing initial and final dye concentration.
Results: Heterostructures are characterized with analytical tools such as X-ray diffraction,
Fourier transform infrared spectroscopy. Band gap of photocatlyst is calculated
by application of UV-Vis spectroscopy. Morphology is seen using scanning electron
microscopy and transmission electron microscopy. Distribution of constituent structures
is observed with energy-dispersive X-ray (EDX) spectroscopy. The structures are used
for photocatalytic degradation of methylene blue dye solution under UV and visible
light irradiation. Heterostructures showed best performance under visible light.
Conclusion: The ternary hybrid nanostructure ZnO-MnO2-Gd2O3 was effectively prepared
by a simple solution combustion method. The ternary compound shows wide
range of absorption by expanding absorption band both in UV and visible regions.
Structures showed better catalytic property under visible light.