In-situ synthesis of graphene nanoribbons with red-fluorescence-emission for constructing heterojunction with ultrafast electron transfer enhances photocatalytic hydrogen production

Photocatalytic hydrogen production is promising for obtaining eco-friendly hydrogen-based energy. Organic compounds have taken a central role as efficient photocatalysts in hydrogen production. Here, we prepared an in-situ pyrene-modified cove-type graphene nanoribbon (cGNRs-Dipyrene) with red fluorescence emission and broad absorption peaks and mixed it with MoS 2 to construct a heterojunction (cGNRs-Dipyrene@MoS 2 ) for photoresponsive hydrolysis hydrogen production. The photocurrent of optimized cGNRs-Dipyrene@MoS 2 heterojunction exhibited a 10-fold increase compared with pure cGNRs-Dipyrene, with a hydrogen evolution rate of 1 786 ​μmol ​h −1 g −1 . Based on in-situ Fourier transform infrared and in-situ X-ray spectroscopy, the active substances at the active sites of cGNRs-Dipyrene@MoS 2 were dynamically monitored, revealing the photocatalytic mechanism. The results show that the cGNRs-Dipyrene@MoS 2 heterojunction can effectively suppress charge recombination, improve interfacial charge transfer, and provide more active adsorption sites and photoinduced conversion reaction centers. This study shows that heterojunctions constructed based on bottom-up customized in situ modified conjugated groups and transition metals can promote photoresponsive water splitting to produce hydrogen, thereby achieving precisely manipulating the morphology and position of the co-catalyst at the atomic level to develop efficient photocatalysts.