Improved photocatalytic activity of carbon-based polymeric semiconductor for efficient decontamination of wastewater: Effect of reaction atmosphere and pyrolysis temperature.

Novel graphitic-carbon nitride (g-C 3 N 4) photocatalyst was synthesized by thermal-pyrolysis of melamine. Pyrolysis reaction temperature (500–700 °C) and gas atmosphere, were optimized to achieve an efficient visible light active photocatalyst. In-depth studies indicate that the reaction temperature of 650ᵒC is an optimum condition for the synthesis of the g-C 3 N 4 photocatalyst. Air atmosphere dominantly favoured a formation of layered g-C 3 N 4 structure compared to those pyrolyzed under argon or nitrogen atmosphere. In contrast to other samples, the optimized g-C 3 N 4 photocatalyst showed significant photodegradation, with a degradation rate of 4.4 × 10−2 min−1, for Rhodamine B(RhB) degradation under simulated solar radiation. A large surface area of 42 m2g-1 and suitable band energetics is attributed to better degradation performance. Image 1 • The optimized pyrolysis temperature for g-C 3 N 4 structure formation is 650 °C. • Air atmosphere favours the synthesis process than that of argon and nitrogen atmospheres. • The optimized photocatalyst had a reasonable surface area of 42 m2g-1. • 96% of the pollutant was degraded in just 45 min of illumination. [ABSTRACT FROM AUTHOR]