Boosting surface charge transfer by aldehyde group grafted on loofah-sponge-like carbon nitride for visible light H2 evolution

Although graphitic carbon nitride (g-C3N4) has broad prospects to resolve the energy crisis, but the rational design of catalyst with high photocatalytic efficiency remains a great challenge. Herein, the hollow porous loofah-sponge-like g-C3N4 incorporated with aldehyde group (LS-ACNx) was achieved via supramolecular self -assembly and thermal polymerization. The detailed characterization results indicated that the excellent per-formance was primarily attributed to the aldehyde group modification and hollow porous loofah-sponge-like structure. The aldehyde groups herein not only dramatically improve the interface charge transfer and sup-press charge recombination, but also adjust the band structure and negative shift the conduction band position. The charge carries concentration of LS-ACN15 was 1.6 times higher relative to bulk g-C3N4 (CN). In addition, the hollow porous loofah-sponge-like morphology enhanced the specific surface area and light-harvesting ability. Benefiting from these, the obtained LS-ACN15 photocatalyst exhibited the superior photocatalytic H2 evolution performance of (10.5 +/- 0.6) mmol g-1h-1, which was 96 times higher than that of the CN (0.109 mmol g -1h- 1), and outperformed the majority of the previously g-C3N4-based photocatalysts. Particularly, the apparent quan-tum yield value was reached to be 16.8 % at 420 nm for LS-ACN15 photocatalyst. This work provides insights into constructing high performance catalysts by tuning energy band structure and charge transfer for energy and environment related field applications.