Carbon-modified TiO2 nanourchin with Ag nanoparticle decoration for environmental remediation

Multifunctional critical nano-composite material assembling Carbon-modified Ag@TiO2 nanourchin was synthesized to investigate visible light photocatalytic activity. The Carbon-modified Ag@TiO2 nanourchin was prepared by a facile two-step chemical synthesis through solvothermal and chemical reduction. Carbon nanospheres as the substrate play a key role for three dimensional nanourchin structure as well as carbon doping. The morphology, crystal structure, and chemical states were characterized carefully by different analytical procedures via transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), energy dispersive X-ray analysis (EDAX), X-ray diffraction (XRD), RAMAN spectroscopy, X-ray photoelectron spectroscopy (XPS) and UV–Vis spectroscopy. It shows that the uniform loaded silver (Ag) on TiO2 surface was metallic Ag0 state. The exist of interstitial carbon and Ag NPs on TiO2 nanostructure collectively enhance the visible light photocatalytic activity. The visible light photocatalytic degradation of methyl orange (MO) studies revealed that Ag@C0.1TiO2 exhibited enhanced photocatalytic efficiency compared with the pure TiO2 nanourchin and commercial TiO2 powder. The improved photocatalytic property can be attributed to lower recombination of the photogenerated e− and h+ pairs in catalyst due to the formation of a Schottky barrier between Ag NPs and TiO2 which improved the surface charge separation greatly and presence of carbon serve as a sensitizer to absorb visible light which inject e- into conduction band (CB) of TiO2.