A review on decolourisation of dyes by photodegradation using various bismuth catalysts

• Spectrum of bismuth catalysts syntheses for different morphologies was compared.
• Study of decolourisation of Methyl Orange, Methylene blue, Rhodamine B, 4BS dyes was done.
• Photocatalytic degradation studied under UV, visible and sunlight.

Photocatalysts are playing a major role in the treatment of industrial effluents. They find an extensive application in the decolourization of textile dyes like methyl orange (MO), methylene blue (MB), rhodamine B (RhB), azo dye (4BS). Organic pollutants like phenol, pentachlorophenol (PCP) are also decomposed in the presence of the photocatalysts under the irradiation of ultraviolet light (UV), visible light or solar light. Recently many researchers have been working for the degradation of dyes using bismuth compounds as a photocatalyst. The photocatalytic activity of the bismuth based catalysts was highly improved by modifying the crystallinity, microstructures, band gap, morphology, particle size and the surface area. In this perspective, the current review deals with the synthesis and applications of BiOX (X = Cl or Br), MBiO2Cl (M = Na, Pb or Cd), Bi2GaTaO7 and Bi2MVOx (M = Ga, Y or Al) photocatalysts. The review will be helpful for scientific community to go for an optimized synthesis of bismuth compound with exceptional qualities for the environmental pollution remediation.