Metal-free efficient photocatalyst for stable visible water splitting via a two-electron pathway

See allHide authors and affiliations

Science  27 Feb 2015:
Vol. 347, Issue 6225, pp. 970-974
DOI: 10.1126/science.aaa3145

You are currently viewing the abstract.

View Full Text

Log in to view the full text

Log in through your institution

Log in through your institution

An enduring catalyst built from carbon

Splitting water into its constituent elements, hydrogen and oxygen, generally requires the assistance of metal catalysts. Liu et al. now show that a metal-free hybrid material composed of carbon and nitrogen can promote this reaction all on its own, with the help of some visible light. The photocatalyst combines one material (C3N4) known to split water into hydrogen and peroxide with a second material (CDot) that breaks the peroxide down before it can damage the first. The robust stability of this hybrid bodes well for practical implementation of optimized analogs in solar energy storage schemes.

Science, this issue p. 970


The use of solar energy to produce molecular hydrogen and oxygen (H2 and O2) from overall water splitting is a promising means of renewable energy storage. In the past 40 years, various inorganic and organic systems have been developed as photocatalysts for water splitting driven by visible light. These photocatalysts, however, still suffer from low quantum efficiency and/or poor stability. We report the design and fabrication of a metal-free carbon nanodot–carbon nitride (C3N4) nanocomposite and demonstrate its impressive performance for photocatalytic solar water splitting. We measured quantum efficiencies of 16% for wavelength λ = 420 ± 20 nanometers, 6.29% for λ = 580 ± 15 nanometers, and 4.42% for λ = 600 ± 10 nanometers, and determined an overall solar energy conversion efficiency of 2.0%. The catalyst comprises low-cost, Earth-abundant, environmentally friendly materials and shows excellent stability.

View Full Text

Stay Connected to Science