Conscientious Design of Zn-S/Ti-N Layer by Transformation of ZnTiO₃ on Electrospun ZnTiO₃@TiO₂ Nanofibers: Stability and Reusable Photocatalytic Performance under Visible Irradiation

Herein, we report the rational design of Zn-S/Ti-N on TiO 2 as a hierarchical nanoarchitecture from the ZnTiO 3 @TiO 2 nanofibers (NFs) through electrospinning followed by a hydrothermal process using l -cysteine as an S/N source. Controlling the hydrothermal temperature, the hierarchical form of NFs exhibited highly efficient visible catalytic behavior for organic dye (i.e., Rhodamine B) degradation since S and N based surface function on the oxide surface resulted in unique interlayer induced strain coupled surface defects. The surface functionalization of the ZnTiO 3 surface with S and N was solidly confirmed by X-ray photo-electrospectroscopy (XPS) and energy-dispersive X-ray (EDX) with elemental mapping results. Inducing the S/N functionality at higher hydrothermal temperature reverses the structural arrangement of ZnTiO 3 favoring the interaction of S preferably with Zn and Ti with N for the formation of ZnS/TiN@TiO 2 NFs. The tunable band function through the Zn-S/Ti-N cofunctionalization exhibited effective long-term catalytic performance under UV and visible irradiation with a degradation rate of 0.0362 and 0.0313 min –1, which is nearly 3.1 and 1.3 times higher than that of the ZnTiO 3 @TiO 2 and ZnTiO 3 –S/N@TiO 2 NFs, respectively. The catalysts are highly photoactive after multiple photocatalytic cycles with stable surface and structural features under visible irradiation. The study could provide new opportunities for designing hierarchical structures in ternary form of nanoscale architectures for effective visible photocatalytic activity.