High Degradation Activity and Quantity Production of Aluminum-Doped Zinc Oxide Nanocrystals Modified by Nitrogen Atoms

Accelerating the Photocatalytic Degradation of Green Dye Pollutants by Using a New Coating Technique for Carbon Nanotubes with Nanolayered Structures and Nanocomposites

The present study has two aims, first to accelerate the degradation of pollutants by coating carbon nanotubes (CNTs) with nanoplatelets or nanocomposites of aluminum zinc oxides and second to fabricate an advanced photocatalyst. Accordingly, Zn-Al layered double hydroxides (LDHs) were grown in the presence of functionalized CNTs during urea hydrolysis. The presence of CNTs led to the formation of LDH nanoplatelets, and TEM images showed that the CNTs were coated with nanoplatelets. The nanoplatelets were thermally treated to form nanocomposite-coated CNTs. Raman spectra demonstrated the successful coating of CNTs with LDHs and nanocomposite. The coated CNTs were very effective in the photocatalytic degradation of industrial pollutants. A kinetics study demonstrated that the rate of photocatalytic degradation of green dye in the presence of CNTs coated with aluminum zinc oxide nanocomposite was five times faster than with the aluminum zinc oxide nanocomposite.

Enhanced photoelectric properties by the coordinating role of doping and modification

Dual technique design in this research has successfully enriched the complementation between doping and surface modification. Here, Co(2+) doped Ag-ZnO nanocomposites (CAZ NCs) are mass produced by the combustion method. The HRTEM image shows that the doped Co(2+) and the surface modified Ag nanoparticles on the ZnO NCs are influential on the preferential orientation. Based on the conductivity formula σ = nqμ and the actual verification, the improved photoelectric properties of CAZ NCs under visible light irradiation are attributed to the enhanced light absorption and the weakened recombination of photogenerated electron-hole pairs. It would be instructive for the sound design concept of subsequent material development.

Mass preparation and novel visible light photocatalytic activity of C and Ag Co-modified ZnO nanocrystals

A combustion method was developed to synthesize the C and Ag co-modified ZnO NCs to enhance its photocatalytic efficiency and practicability. The results showed that the doped Ag was significant to promote the photocatalytic activity, and the optimum content was 2% molar ratio of Ag to Zn atom. The degradation rate under visible light increased by 150% compared with C-ZnO NCs, while by more 1233.3% than pure ZnO photocatalyst. There were some new little particles with grain size about 10 nm on the C-ZnO NCs surface, which may state for the existence of Ag atoms. The synergy effect of Ag and carbon elements was proposed to explain the mechanism of enhanced photocatalytic performance under visible light irradiation.