Degradation of toxic industrial dyes using SnO2/g-C3N4 nanocomposites: Role of mass ratio on photocatalytic activity

Efficient and cost-effective SnO2/g-C3N4 photocatalysts have been developed via simple wet chemical method using urea as a g-C3N4 precursor. The effect of different mass ratios (SnO2: g-C3N4 = 1-5:5-1) on the synthesized photocatalysts was investigated. XRD, SEM/EDS, FE-SEM, HR-TEM and XPS analysis techniques were used for the characterization of adsorbents which also confirmed the strong bonding of SnO2 with g-C3N4. The photo-catalytic degradation process has been chosen for the treatment of synthetic wastewater containing organic and textile dyes (Rhodamine-B, RhB, and Remazol Brilliant Red X-3BS, RbX).The synthesized photocatalysts exhibited excellent degradation efficiency for the pollutants due to the synergistic effect of g-C3N4 and SnO2. Kinetic studies for RhB degradation revealed the highest rate constant (0.0485 min(-1)) for the SnO2/g-C3N4-1:1 catalyst, which was ca. 33 times higher than that of pure g-C3N4. Furthermore, photocatalysts exhibited high durability and stability during five recycling experiments. In addition, a mechanism for the photocatalytic degradation of pollutants over SnO2/g-C3N4 via photocatalysis has also been explained.