A metal-free polymeric photocatalyst for hydrogen production from water under visible light

Abstract

The production of hydrogen from water using a catalyst and solar energy is an ideal future energy source, independent of fossil reserves. For an economical use of water and solar energy, catalysts that are sufficiently efficient, stable, inexpensive and capable of harvesting light are required. Here, we show that an abundant material, polymeric carbon nitride, can produce hydrogen from water under visible-light irradiation in the presence of a sacrificial donor. Contrary to other conducting polymer semiconductors, carbon nitride is chemically and thermally stable and does not rely on complicated device manufacturing. The results represent an important first step towards photosynthesis in general where artificial conjugated polymer semiconductors can be used as energy transducers.

Origin and Perspectives of the Photochemical Activity of Nanoporous Carbons

“…The authors also observed the coexistence of both p‐ and n‐type charge carriers in functionalized nanoporous carbons. The transition from n‐type to p‐type materials upon functionalization has been reported for carbon‐based materials, including graphene nanoribbons 61, 62. Gomis‐Berenguer described a similar behavior on nanoporous carbons with a low functionalization level, reporting frequency‐dependent impedance measurements for some carbons 63.…”

CO2 Reduction: From the Electrochemical to Photochemical Approach

“…It has a layered structure analogous to graphite and ideally built from tri‐s‐triazine units 163. In 2009, Domen and co‐workers first reported its photocatalytic activity for hydrogen production under visible light 164. Great efforts have been invested on C 3 N 4 to explore its potential for photocatalytic CO 2 reduction since 2013 165, 166, 167, 168.…”

Tuning the Intrinsic Properties of Carbon Nitride for High Quantum Yield Photocatalytic Hydrogen Production

“…It has suitable energy levels (band gap ≈2.7 eV; LUMO ≈ −1.1 V vs SHE; HOMO ≈ +1.6 V vs SHE9) straddling the redox potential required (i.e., 0.0 V vs SHE for proton reduction and +1.23 V vs SHE for water oxidation2) for water splitting 8, 15, 31. These HOMO and LUMO values are predictions from computational results using DFT.…”