One-Pot Synthesis and Enhanced Vis-NIR Photocatalytic Activity of NiTiO₃/TiO₂ Templated by Waste Tobacco Stem-Silks

Synthesis of the photocatalysts with near-infrared light response usually involves upconversion materials or plasmon-assisted noble metals. Herein, NiTiO₃/TiO₂ was synthesized by using waste tobacco stem-silks as biotemplates and tetra-tert-butyl orthotitanate and nickel nitrate as precursors in a one-pot procedure. NiTiO₃(1.0)/TiO₂(TSS) with a mass percent of Ni 1.0% exhibited very high visible-light photocatalytic efficiency in photodegradation of tetracycline hydrochloride (TC), which is 8.0 and 2.3 times higher than TiO₂ prepared without templates and TiO₂(TSS) prepared without Ni, respectively. Interestingly, NiTiO₃(1.5)/TiO₂(TSS) even exhibited good activity under NIR light (λ = 840~850 nm) without upconversion materials or plasmon-assisted noble metals, which is 2.8 and 2.2 times than TiO₂ prepared without templates and TiO₂(TSS), respectively. The boosting photocatalytic activity has been shown to be attributed to efficient charge separation and transfer across a direct Z-scheme heterojunction between NiTiO₃ and TiO₂ and enhanced light-harvesting ability of special flaky structure reduplicated from tobacco stem-silks. This reported strategy provides a new idea for the multifunctional utilization of waste tobacco stem-silks and the synthesis of novel photocatalysts for the potential application in wastewater treatment.