Synthesis of g-C₃N₄ nanorods for visible-light photocatalytic degradation of methylene blue, methylene orange and rhodamine-B

ABSTRACT

A novel recoverable photocatalyst g-C₃N₄ nanorods have been synthesised by using melamine and adopting the hydrothermal method. Graphitic carbon nitride has been characterised by a wide range of characterisation techniques like XRD, SEM, EDX, PL and FTIR. Their effect on degradation of organic dyes, methylene blue (MB), methylene orange (MO) and Rhodamine-B (Rh-B) have been studied along with factors of pH 0–5 and pH 8–14. Remarkably, g-C₃N₄ could degrade 99% of MO, 97% of MB and 99.9% of Rh-B with pH 0–5, and 97.7% of MO, 98% of MB and 99.5% Rh-B with pH 8–12, respectively. This catalyst has superior dye degradation efficiency (99.9% and 99.5%) for Rh-B for both the factors pH 0–5 and pH 8–12. The trapping experiment results portrayed that the superoxide radical anion (•O²−) and holes (h⁺) have played major role for the degradation of Rh-B, MB and MO dyes. Based on the trapping experiment results, a tentative photocatalytic mechanism has also been proposed.

KEYWORDS:

• Photocatalyst
• g-C₃N₄
• organic dyes
• visible light
• degradation

Funding

Author Dr Ghulam Nabi acknowledges the Higher Education Commission (HEC), Pakistan, for providing funding under NRPU Research Project No.6502 and 6510.

Disclosure statement

No potential conflict of interest was reported by the authors.