Synthesis of Ag nanoparticles-decorated on CNTs/TiO2 nanocomposite as efficient photocatalysts via nanosecond pulsed laser ablation

A simple, reproducible, and non-surfactant self-templating approach was developed for the synthesis of silver nanoparticles decorated on CNTs/TiO2 nanocomposite via a nanosecond pulsed laser ablation method. In addition, the effective use of the resulting nanocatalysts was carried out in the enhanced photocatalytic degradation of methylene blue dye contaminant. Following the synthesis of the nanocomposite catalysts, their morphology, heterostructure, and the nature of incorporation of their constituents were confirmed by TEM and SEM microscopy. In addition, characteristic diffraction patterns of the materials were studied by XRD powder diffraction method, confirming the crystalline nature of the nanocatalysts. The photoluminescence (PL) analysis provided information about the surface defects present as well as the electron-hole recombination properties of the prepared nanocatalysts. Despite the poor ultraviolet light absorption of the neat CNT and the TiO2 constituents beyond 400 nm, an efficient ultraviolet light-induced photodegradation of the methylene blue dye was successfully achieved. In this, by carrying out 50 min of ultraviolet light irradiation of the dye in the presence of the TiO2/CNT and the Ag/TiO2/CNT nanocomposite catalysts, 89.8% and 96 % reduction efficiencies were achieved, respectively. The experimental error associated with the photodegradation efficiency was within +/- 3%. The ultraviolet light-induced catalytic degradation of the dye follows first-order reaction kinetics, with rate constants of 3.95 x10-2 min-1 and 4.56 x 10-2 min-1 associated with the TiO2/CNT and the Ag/TiO2/CN catalyzed reactions, respectively.

Automated summary

A simple and reproducible self-templating method was developed to synthesize silver nanoparticles decorated on CNTs/TiO2 nanocomposite using nanosecond pulsed laser ablation. The resulting nanocatalysts showed enhanced photocatalytic degradation of methylene blue dye contaminant. Morphology, heterostructure, and the nature of incorporation of the nanocomposite catalysts were confirmed by TEM and SEM microscopy. XRD analysis confirmed the crystalline nature of the nanocatalysts. PL analysis provided information about surface defects and electron-hole recombination properties of the prepared nanocatalysts. Efficient ultraviolet light-induced photodegradation of the dye was achieved using the TiO2/CNT and Ag/TiO2/CNT nanocomposite catalysts.