Fabrication of sulfur doped exfoliated gCN photocatalyst for enhanced visible light degradation of pernicious organic pollutants and their photocatalytic antibacterial activity

Abstract

The synthesis of sulfur-doped exfoliated graphitic carbon nitride (S-gCN) photocatalyst was achieved by the implementation of a two-step calcination technique. The XRD results revealed that all the fabricated photocatalytic materials were crystalline in nature. The inclusion of 5% sulfur in gCN led to a conspicuous escalation in the surface area of photocatalyst, rising from 10.294 to 61.185 m²g⁻¹. Morphological scrutiny of the samples using FE-SEM revealed that pristine gCN exhibited tightly stacked small nanosheets, whereas inclusion of sulfur and exfoliation resulted in generation of loosely distributed large nanosheet. Furthermore, the inclusion of sulfur also induced a shift in the energy band gap (Eg) from 2.81 eV to 2.63 eV, making it felicitous for investigation as proficient visible light photocatalyst. Additionally, the photoluminescence photo-induced charge carrier recombination behavior revealed a reduced peak intensity for 5% S-gCN compared to other synthesized compositions. This observation can be directly linked to the minimized electron-hole pairs recombination during photocatalysis, underscoring its superior photocatalytic performance. Our findings revealed that the 5% S-gCN photocatalyst exhibit the most promising attributes, it degraded Tetracycline drug, Chlorpyrifos pesticide and Eriochrome Black T dye under visible light irradiation almost ∼4 times more efficiently than pristine gCN. Additionally, exceptional visible light photocatalytic antibacterial efficacy was also perceived by 5% S-gCN against S. aureus bacteria. Overall, the present research sheds light on how doping and exfoliation interact to modify the structure and catalytic properties of gCN, paving the way for the development of outstanding performance, visible light-responsive efficient photocatalysts for environmental restoration.

Keywords: Doping; Exfoliation; Metal free catalyst; Staphylococcus aureus; Tetracycline; Visible light photocatalysis; gCN.