Tungsten oxide （WO3） nanorods, which were used to load platinum （Pt） nanoparticles, were investi- gated. H2WO4 nanorods with diameters from 10 to 50 nm were obtained when tungsten precursor was added into homogenous double-walled carbon nanotubes （DWCNT） and ethylene glycol （EG） solution. Nanosized rod-like WO3 were achieved after calcination of the DWCNT/H2W04 composite. Sphere-like Pt nanoparticles were loaded on the surface of the nanorods by EG in-situ reduction. Pt particles were isolated by DWCNT/WO3 nanorods and secondary accumulation could be prevented when Pt particles appeared in the DWCNT/WO3 nanorod/EG dispersion solution. Therefore, Pt nanoparticles with mean di- ameters of 2-6 nm could be obtained. Pt-deposited on DWCNT/WO3 nanorods exhibited high electrochemical activity, which could facilitate the low-cost mass production of Pt catalyst.
The preparation of WO_(3) nanorods by double-walled carbon nanotube(DWCNT)template was investi-gated in this study.Owing to that the prepared H_(2)WO_(4)can be isolated by the homogenously dispersed DWCNT bun-dles and secondary accumulation can be avoided effec-tively,the growth of H_(2)WO_(4) can be restrained,and H_(2)WO_(4) nanorods with diameter of 10–50 nm can be prepared.After calcination of the prepared DWCNT/H_(2)WO_(4) com-posite in oxygen,WO_(3) nanorods with diameter of 10–100 nm and high specific surface area of 16.4 m^(2)·g^(-1) can be obtained.It is concluded that the DWCNTs play an im-portant role in the effective mediation of the morphology and size of nano-WO_(3).
In this study, double-walled carbon nanotubes （DWCNTs） in ethylene glycol （EG） and N,N-dimethyl- formamide （DMF） media were investigated by a simple ultrasonication method. Homogeneously dispersed and highly concentrated DWCNTs are in EG （95 vol%） and DMF （5 vol%） media without the addition of surfactant. Surface structure and crystallinity of DWCNTs undergo minimal change. The highly concentrated dispersion state of DWCNTs helps in Pt loading. Pt particles prepared in the homogenous dispersion system have small sizes and are uniformly distributed. The prepared Pt catalysts display a similar electrochemical activity to catalysts pre- pared in EG system with low concentration. The results demonstrate that homogenously dispersed and highly concentrated DWCNTs can realize mass production of Pt/ DWCNT catalysts with high electrochemical activity and low cost.
