Pt nanoparticles decorated chitosan/ZnTiO3: Ternary visible-light photocatalyst for ultrafast treatment of insecticide imidacloprid and methylene blue

•PtNPs/chitosan/ZnTiO3 ternary photocatalyst via sol-gel and photoreduction techniques•Ultrafast removal of insecticide Imidacloprid and methylene blue under visible light•Enhanced light absorption with suppression of photogenerated charge carriers•The rate constant (k) of PtNPs/chitosan/ZnTiO3 is ⁓ 2.2 times larger than pure ZnTiO3•The PtNPs/chitosan/ZnTiO3 exhibited outstanding stability and reusability Design and fabrication of proficient visible light photocatalysts require dedicative effort and is an existing provoking research task. The present chaotic environmental scenario urgently demands to contemplate and work exhaustively on this critical issue. Therefore, the current research focused to design ultrafast visible light ternary photocatalysts of ZnTiO3 nanostructures coupling with chitosan (CTSN) and Pt nanoparticles (PtNPs). Pt and CTSN associated ZnTiO3 ternary photocatalyst was successfully fabricated by modified sol-gel method followed by ultra-sonication and photo-reduction methodologies. The research findings confirmed the formation of rhombohedral phase of ZnTiO3 involved in successful creation of ternary nanocomposite with PtNPs (4-15 nm) dispersed on ZnTiO3 (size ∼80-250 nm) and micron-sized sheets of CTSN. The newly fabricated Pt@CTSN/ZnTiO3 ternary photocatalyst was found to be highly ultrafast under visible light illumination, yielding 94.48 % degradation of target insecticide imidacloprid just in 25 min, representing ∼2.20 times greater proficiency than bare ZnTiO3 photocatalyst. Furthermore, the Pt@CTSN/ZnTiO3 was found to be highly destructive towards colored MB dye upon visible light exposure. The highly efficient and accelerated photocatalytic activity is attributed to the mesoporous structure, increased surface area, lowered bandgap with enhanced light absorption and a suppression in the recombination rate of the photogenerated charge carriers. [Display omitted]