Partially conjugated polyvinyl chloride-modified TiO2 nanoparticles for efficient visible-light-driven photocatalytic reduction of aqueous Cr(VI)

• Mixing and heating synthesis of partially conjugated PVC-modified TiO2 nanoparticles.
• Strong absorption of visible-light.
• High visible-light-driven photocatalytic activity in the reduction of aqueous Cr(VI).

Partially conjugated polyvinyl chloride (CPVC)-modified TiO2 nanoparticles were synthesized by heating the composite of polyvinyl chloride and TiO2 nanoparticles in air at 150 °C for 1 h (the optimal heating duration among the investigated 0.5 h, 1 h, 2 h, 3 h and 4 h to obtain the most efficient CPVC/TiO2 composite). The characterization results from X-ray diffraction, Raman spectra, X-ray photoelectron spectroscopy and high resolution transmission electron microscopy confirmed the formation of TiO2 nanoparticles modified with CPVC. The UV–vis diffuse reflectance spectra indicated that the as-synthesized CPVC-modified TiO2 nanoparticles had remarkable visible-light-absorbing ability. The photocatalytic experiments demonstrated that the as-synthesized CPVC-modified TiO2 nanoparticles exhibited high photocatalytic activity in the reduction of aqueous Cr(VI) under visible-light (λ>420 nm) irradiation, whereas sole CPVC and TiO2 nanoparticles exhibited no photocatalytic activity in the reduction of aqueous Cr(VI) under visible-light (λ>420 nm) irradiation.