Journal
JOURNAL OF MATERIALS CHEMISTRY A
Volume 2, Issue 47, Pages 20338-20344Publisher
ROYAL SOC CHEMISTRY
DOI: 10.1039/c4ta04100c
Keywords
-
Funding
- Research Corporation for Science Advancement
- National Science Foundation (NSF) [CBET 1133099]
- China Scholarship Council (CSC)
Ask authors/readers for more resources
Graphitic carbon nitride (g-C3N4) is a promising visible-light-responsive photocatalyst for hydrogen generation from water. As we show here, the photocatalytic activity of g-C3N4 is limited by structure defects generated during the calcination process. Specifically we find that the photocatalytic hydrogen production rate from aqueous methanol is inversely related to the calcination temperature (520-640 degrees C). The highest activity of 0.301 mmol h(-1) g(-1) is observed for the sample prepared at the lowest processing temperature. Surface photovoltage (SPV) spectroscopy shows that the maximum photovoltage is reduced (from 1.29 V to 0.62 V) as the processing temperature is increased, in accordance with higher defect concentrations and faster electron-hole recombination. The defects also produce additional optical absorption in the visible spectra and cause a red shifted, weakened photoluminescence (PL). Based on the sub-gap signal in the SPV and PL spectra, defect energy levels are +0.97 V and -0.38 V (vs. NHE) in the band gap of the material. According to Fourier transform infrared (FTIR) spectra, the defects are due to amino/imino groups in the g-C3N4 lattice.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available