Construction of S-scheme heterojunction catalytic nanoreactor for boosted photothermal-assisted photocatalytic H2 production

Reasonable design of heterojunction band structure and strengthening of the photothermal effect is an important method to promote the photothermal-assisted photocatalytic H2 production activity of photocatalysts. Herein, a composite material named as Co3O4/CNNVs S-scheme heterojunction nanoreactor was constructed by loading Co3O4 nanoparticles on the surface of g-C3N4 nanovesicles (CNNVs) through a simple hydrothermal method and used to achieve efficient photothermal-assisted photocatalytic H2 production. In the absence of Pt as a cocatalyst, Co3O4/CNNVs-22.5 exhibited a photocatalytic H2 production rate up to 772.9 μmol g-1h−1 under irradiation with a 300 W Xenon lamp, which is much higher than that of pure CNNVs (15.5 μmol g-1h−1). In the Co3O4/CNNVs photothermal-assisted photocatalytic system, the synergistic effect of the strong photothermal effect of Co3O4 nanoparticles and the thermal insulation effect of hollow CNNVs nanoreactor was shown to be the main reasons for promoting the surface temperature increase of the heterojunction photocatalyst, which effectively facilitates the separation and transfer of photo-generated carriers, thus increasing the photocatalytic H2 production. In addition, the S-scheme heterojunction formed between Co3O4 and CNNVs optimize the charge transfer path. This work presents a reasonable design of highly efficient photocatalyst with a S-scheme heterojunction nanoreactor for the photothermal-assisted photocatalysis.