A visible light-driven NaTiO3/g-C3N4 heterojunction photocatalyst for ultra-fast organic dye degradation

Most conventional dye treatment methods have limited efficacy as they are expensive, time-intensive and result in incomplete dye removal from water. Addressing these issues, this work reports the fabrication of a NaTiO3/g-C3N4 heterojunction photocatalyst, which was utilized for the advanced oxidation process under sunlight irradiation to remove crystal violet (CV) and methylene blue (MB) dyes and their binary mixture. The perovskite NaTiO3 is synthesized via a simple hydrothermal method and combined with graphitic carbon nitride, formed through the thermal decomposition of melamine, to fabricate the heterojunction. The scanning electron microscopy (SEM) images reveal that spherical NaTiO3 nanoparticles are aggregated on the sheet-like surface of g-C3N4 and structural analysis utilizing the XRD pattern confirms the formation of a heterojunction. From the Tauc plot the bandgap of the material is estimated to be 2.3 eV. The complete degradation of MB was observed within 25 min, while CV and the binary mixture require 20 min for complete degradation. The high visible light absorption of NaTiO3 and large surface area of g-C3N4 were attributed to the enhanced catalytic performance of the heterojunction. Additionally, scavenger studies indicated that the radical species h(+) and (OH)-O-center dot played a crucial role in the photocatalytic degradation of the dyes. Reusability studies confirm good stability up to five cycles of dye degradation. The results establish the NaTiO3/g-C3N4 heterojunction as an efficient photocatalyst to remove organic dyes from water, thus having immense potential in water purification.

Automated summary

This study reports the fabrication of a NaTiO3/g-C3N4 heterojunction photocatalyst for efficient removal of organic dyes from water. The heterojunction exhibits excellent catalytic performance, degrading dyes quickly under visible light irradiation. This research has significant potential for applications in water purification.