Beware of Doping: Ta2O5 Nanotube Photocatalyst Using CNTs as Hard Templates

Alexey Cherevan*, Paul Gebhardt, Andreas Kunzmann, Rubén D. Costa, Dominik Eder


研究成果: Article査読

4 被引用数 (Scopus)


Nanostructuring constitutes a promising strategy to increase efficiency and stability of contemporary photocatalysts. Here, we report on the synthesis of highly crystalline Ta2O5 nanotubes (NTs) by using carbon nanotubes (CNTs) as sacrificial hard templates and elucidate the role of residual Fe nanoparticles - often used as catalyst for the CNT growth - on their photocatalytic performance toward H2 evolution. We show that, when using as grown CNTs, the resulting Ta2O5 NTs contained detectable amounts of Fe and possessed negligible photocatalytic activity. When CNTs were, however, purified from Fe by thermally annealing the CNTs at 2100 °C, the same synthetic procedure yielded pure Ta2O5 NTs that showed a 40-fold increase in activity compared to the Fe-containing counterpart. A complementary set of analytical techniques in a combination with additional model experiments indicate that the detrimental effect of the residual Fe on the photocatalytic activity originates from atomic doping and formation of a segregated FeOx phase within the Ta2O5 matrix that can both act as efficient electron traps. Our result highlights that the presence of residual catalyst needs to be taken into account when using CNTs as hard templates and generally illustrates a possible effect of unintentional dopants that are often not considered in preparing functional nanostructures.

ジャーナルACS Applied Energy Materials
出版ステータスPublished - 2018 3月 26

ASJC Scopus subject areas

  • 化学工学(その他)
  • エネルギー工学および電力技術
  • 電気化学
  • 材料化学
  • 電子工学および電気工学


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