TY  - JOUR
A1  - Shalom, Menny
A1  - Guttentag, Miguel
A1  - Fettkenhauer, Christian
A1  - Inal, Sahika
A1  - Neher, Dieter
A1  - Llobet, Antoni
A1  - Antonietti, Markus
T1  - In situ formation of heterojunctions in modified graphitic carbon nitride: synthesis and noble metal free photocatalysis
JF  - Chemistry of materials : a publication of the American Chemical Society
N2  - Herein, we report the facile synthesis of an efficient roll-like carbon nitride (C3N4) photocatalyst for hydrogen production using a supramolecular complex composed of cyanuric acid, melamine, and barbituric acid as the starting monomers. Optical and photocatalytic investigations show, along with the known red shift of absorption into the visible region, that the insertion of barbituric acid results in the in situ formation of in-plane heterojuctions, which enhance the charge separation process under illumination. Moreover, platinum as the standard cocatalyst in photocatalysis could be successfully replaced with first row transition metal salts and complexes under retention of 50% of the catalytic activity. Their mode of deposition and interaction with the semiconductor was studied in detail. Utilization of the supramolecular approach opens new opportunities to manipulate the charge transfer process within carbon nitride with respect to the design of a more efficient carbon nitride photocatalyst with controlled morphology and optical properties.
Y1  - 2014
U6  - https://doi.org/10.1021/cm503258z
SN  - 0897-4756
SN  - 1520-5002
VL  - 26
IS  - 19
SP  - 5812
EP  - 5818
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Shalom, Menny
A1  - Inal, Sahika
A1  - Fettkenhauer, Christian
A1  - Neher, Dieter
A1  - Antonietti, Markus
T1  - Improving Carbon Nitride Photocatalysis by Supramolecular Preorganization of Monomers
JF  - Journal of the American Chemical Society
N2  - Here we report a new and simple synthetic pathway to form ordered, hollow carbon nitride structures, using a cyanuric acid melamine (CM) complex in ethanol as a starting product. A detailed analysis of the optical and photocatalytic properties shows that optimum hollow carbon nitride structures are formed after 8 h of condensation. For this condensation time, we find a significantly reduced fluorescence intensity and lifetime, indicating the formation of new, nonradiative deactivation pathways, probably involving charge-transfer processes. Enhanced charge transfer is seen as well from a drastic increase of the photocatalytic activity in the degradation of rhodamine B dye, which is shown to proceed via photoinduced hole transfer. Moreover, we show that various CM morphologies can be obtained using different solvents, which leads to diverse ordered carbon nitride architectures. In all cases, the CM-C3N4 structures exhibited superior photocatalytic activity compared to the bulk material. The utilization of CM hydrogen-bonded complexes opens new opportunities for the significant improvement of carbon nitride synthesis, structure, and optical properties toward an efficient photoactive material for catalysis.
Y1  - 2013
U6  - https://doi.org/10.1021/ja402521s
SN  - 0002-7863
VL  - 135
IS  - 19
SP  - 7118
EP  - 7121
PB  - American Chemical Society
CY  - Washington
ER  -