Preparation of Ta2O5 nanoparticles by using cathode glow discharge electrolysis

Tantalum pentoxide nanoparticles (Ta2O5 NPs) were fabricated by cathode glow discharge electrolysis (CGDE) generated between a needle-like platinum wire cathode and a tantalum foil anode in 6 g L-1 Na2SO4 electrolyte solution containing 5 ml hydrofluoric acid (HF) and 0.075 g cetyltrimethyl ammonium bromide (CTAB). The chemical structure, composition and morphology of the obtained powder were analyzed by using XRD, FT-IR, SEM/EDS, XPS and UV-vis DRS. The results found that Ta2O5 NPs with orthorhombic structure and wide band gap (3.6 eV) are successfully fabricated at 500 V discharge voltage in about 3 h. CTAB as a stabilizing agent can reduce the agglomeration due to forming CTA(+) and attaching the surface of the synthetic products. A possible preparation mechanism of Ta2O5 NPs is proposed. Firstly, the tantalum foil anode is oxidized to form a compact Ta2O5 layer. Then, Ta2O5 surface is etched to form soluble [TaF7](2-) complexes in the presence of HF. After that, soluble [TaF7](2-) complexes can react with H2O to form Ta(OH)(5). Finally, Ta(OH)(5) is further converted to Ta2O5 from plasma-liquid interface into solution.

Automated summary

Tantalum pentoxide nanoparticles were successfully fabricated using cathode glow discharge electrolysis, with CTAB acting as a stabilizing agent to reduce agglomeration. The preparation mechanism involves oxidation of tantalum foil to form a Ta2O5 layer, etching of the Ta2O5 surface to form soluble complexes, and conversion to Ta2O5.