Phosphorus-Doped Carbon Nitride Solid: Enhanced Electrical Conductivity and Photocurrent Generation

• Published in: Journal of the American Chemical Society Vol. 132; no. 18; pp. 6294 - 6295
• Main Authors: Zhang, Yuanjian, Mori, Toshiyuki, Ye, Jinhua, Antonietti, Markus
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 12.05.2010
• ISSN: 0002-7863; 1520-5126; 1520-5126
• DOI: 10.1021/ja101749y

As a new kind of polymeric semiconductors, graphitic carbon nitride (g-C3N4) and its incompletely condensed precursors are stable up to 550 °C in air and have shown promising photovoltaic applications. However, for practical applications, their efficiency, limited e.g. by band gap absorption, needs further improvement. Here we report a “structural doping” strategy, in which phosphorus heteroatoms were doped into g-C3N4 via carbon sites by polycondensation of the mixture of the carbon nitride precursors and phosphorus source (specifically from 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid). Most of the structural features of g-C3N4 were well retained after doping, but electronic features had been seriously altered, which provided not only a much better electrical (dark) conductivity up to 4 orders of magnitude but also an improvement in photocurrent generation by a factor of up to 5. In addition to being active layers in solar cells, such phosphorus-containing scaffolds and materials are also interesting for polymeric batteries as well as for catalysis and as catalytic supports.