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An Investigation into the Stability of Graphitic C3N4 as a Photocatalyst for CO2 Reduction
journal contribution
posted on 2018-11-27, 00:00 authored by Francesca
R. Pomilla, Maria A. L. R.
M. Cortes, Jeremy W. J. Hamilton, Raffaele Molinari, Giuseppe Barbieri, Giuseppe Marcì, Leonardo Palmisano, Preetam K. Sharma, Alan Brown, John A. ByrneThe
increasing CO2 concentration in the atmosphere exerts
a significant influence on global warming and climate change. The
capture and utilization of CO2 by conversion to useful
products is an area of active research. In this work, the photodriven
reduction of CO2 was investigated using graphitic carbon
nitride (g-C3N4) as a potential photocatalyst.
The photocatalytic reduction of CO2 was investigated with
g-C3N4 powder immobilized on a glass support
in a batch gas-phase photoreactor. The experiments were carried out
under UV–vis irradiation at 70 °C and an initial pressure
of 2.5 bar. The only gas-phase product detected during the irradiation
of the g-C3N4 in the presence of CO2 was CO, and the rate of production was observed to decrease over
time. Oxygen-doped g-C3N4 was also tested for
CO2 reduction but had efficiency lower than that of the
parent g-C3N4. Repeated cycles of photocatalytic
CO2 reduction showed a decline in the activity of the g-C3N4. In the absence of CO2 some CO generation
was also observed. Characterization of used and unused materials,
using FTIR and XPS, showed an increase in the oxygen functional groups
following UV–vis irradiation or thermal treatment. While others
report the use of g-C3N4 as a photocatalyst,
this work highlights the important need for replicates and control
testing to determine material stability.