Oxygen-doped carbon nitride aerogel: A self-supported photocatalyst for solar-to-chemical energy conversion

Abstract

Oxygen-doped carbon nitride aerogel (OCNA) was successfully fabricated through a facile self-assembly method combined with hydrothermal process, without adopting any harmful solvents or cross-linking agents. The assembly mechanism of carbon nitride aerogel (CNA) with different morphologies was discussed. OCNA exhibited much faster charge separation efficiency, longer carriers' lifetime than bulk carbon nitride (BCN). More importantly, oxygen-doping adjusted the band structure of carbon nitride, leading to a more negative conduction band (CB) position and narrower band gap (Eg). The spectral response range of OCNA was extended greatly and the hydrogen evolution rate (HER) of OCNA (λ > 510 nm) was about 26 times as high as that of BCN prepared herein. The apparent quantum yield (AQY) was 20.42% at 380 nm, 7.43% at 420 nm and 1.71% at 500 nm. This work paves a facile colloid chemistry strategy to assemble 3D CAN that could be widely adopted in the sustainability field.

Boosting photocatalytic oxidation on graphitic carbon nitride for efficient photocatalysis by heterojunction with graphitic carbon units

“…For the photovoltammograms of CN and CN-x under chopped visible light (wavelength >400 nm) were recorded inFigure 3(d), where the MPD-modified samples show enhanced cathodic and anodic photocurrent than CN if MPD level is lower than 3.5 %. In a previous report, oxygen doping in CN was reported to increase the hydrogen evolution reaction as well as the oxygen evolution reaction, but the oxygen doping in carbon-nitride aerogel seems to decrease the redox potential of the conduction band and the bandgap, E g[63]. As we observed a significant increase in the redox potential of conduction band, the effect of oxygen in our case should be minor.…”

Intramolecular Charge Transfer and Extended Conjugate Effects in Donor–π–Acceptor‐Type Mesoporous Carbon Nitride for Photocatalytic Hydrogen Evolution

“…The weak O signal may come from the incomplete dissociation of precursors or adsorbed oxygen of adventitious contaminants (Figure S4). The peak at 532.5 eV was attributed to adsorbed H 2 O and the peak at 533.7 eV was attributed to O=C derived from urea or ID. The high‐resolution C 1s signals (Figure C) of the two samples were fitted into two peaks at 284.7 and 288.1 eV, which were assigned to the aromatic carbon atoms and the sp 2 hybridized carbon (N−C=N) in the s‐triazine ring, respectively .…”

Highly selective oxidation of methane to methanol at ambient conditions by titanium dioxide-supported iron species

“…recombination by the surface decoration 53,54. Intensity-modulated photocurrent spectroscopy (IMPS) and intensity-modulated photovoltage spectroscopy (IMVS) measurements as shown inSupplementary Figures 25 and 26also suggest better charge separation by iron decoration [55][56][57][58]. 0.33 metalwt.% FeOx/TiO2 has a charge collection efficiency of 98%, which is almost double that of bare TiO2, indicating dramatically enhanced charge transfer and separation 55.…”