Photocatalytic Hydrogen Production using Polymeric Carbon Nitride with a Hydrogenase and a Bioinspired Synthetic Ni Catalyst

Abstract

Solar-light-driven H2 production in water with a [NiFeSe]-hydrogenase (H2ase) and a bioinspired synthetic nickel catalyst (NiP) in combination with a heptazine carbon nitride polymer, melon (CNx), is reported. The semibiological and purely synthetic systems show catalytic activity during solar light irradiation with turnover numbers (TONs) of more than 50 000 mol H2 (mol H2ase)−1 and approximately 155 mol H2 (mol NiP)−1 in redox-mediator-free aqueous solution at pH 6 and 4.5, respectively. Both systems maintained a reduced photoactivity under UV-free solar light irradiation (λ>420 nm).

Carbon nitride–TiO2 hybrid modified with hydrogenase for visible light driven hydrogen production

“…3,4,9 A part of this improvement can be attributed to the direct optical electron transfer (pathway 3) within CN x –TiO 2 , which draws the absorption of solar light significantly into the visible spectrum.…”

“…9 A long-term experiment with H 2 ase (50 pmol), CN x –TiO 2 (5 mg) and added MV 2+ (5 μmol) in aqueous EDTA (0.1 M) at pH 6 was performed with both λ > 300 nm light and with visible light only ( λ > 420 nm). Under UV-visible irradiation after 72 h, the CN x –TiO 2 –MV–H 2 ase system produced 193 μmol H 2 with a TON H 2 ase of > 3.8 × 10 6 and an initial TOF H 2 ase of 35 s –1 (Fig.…”

Wiring of Photosystem II to Hydrogenase for Photoelectrochemical Water Splitting

“…49 Light-driven H 2 production using H 2 ase has been achieved in the past in combination with light harvesting materials, but only in the presence of a sacrificial electron donor. 38,43,50,51 Complete light-driven water splitting containing a H 2 ase-based half reaction had not previously been reported in vitro.…”

Macroscopic 3D Porous Graphitic Carbon Nitride Monolith for Enhanced Photocatalytic Hydrogen Evolution

“…[ 1e , 3, 4 ] Nevertheless, it still suffers from some drawbacks, such as small specifi c surface area (SSA), low visible light utilization effi ciency, and rapid recombination of photogenerated carriers. [ 3,5 ] For these reasons, many impressive results have been obtained by modifying g-CN by coupling with other materials such as carbon dots, [ 1e ] graphene, [ 6 ] hydrogenase, [ 7 ] semiconductors, [ 8 ] aromatic compounds, [ 9 ] and doping with heteroatoms such as P, [ 10 ] F, [ 11 ] O, [ 12 ] B, [ 11,13 ] I, [ 5a ] S, [ 14 ] and Fe, [ 15 ] and introducing nitrogen vacancies [ 16 ] to overcome the aforementioned problems. Besides, a variety of forms of nanostructured g-CN including nanosheets, [ 17 ] Direct evidence for the formation of g-CN is obtained using X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, thermogravimetry (TG), and X-ray photoelectron spectroscopy (XPS) analysis.…”