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

Herein, self-supported 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 fabrication mechanism of OCNA was discussed. OCNA exhibited much faster charge separation efficiency, longer carriers’ lifetime than bulk carbon nitride (BCN). More importantly, oxygen-doping led to a more negative conduction band (CB) position and narrower band gap (Eg). Hence, the spectral response range of OCNA was extended dramatically and the hydrogen evolution rate (HER) of OCNA (λ > 510 nm) was about 26 times as high as that of BCN prepared herein. OCNA exhibited a remarkable apparent quantum yield (AQY) of 20.42% at 380 nm, 7.43% at 420 nm and 1.71% at 500 nm, superior to most of the reported C3N4-based materials. This work paves a facile colloid chemistry strategy to assemble self-supported 3D CNA that could be widely adopted in the sustainability field.