Graphdiyne (g-CnH2n-2) Coupled with Co3O4 Formed a Zero-Dimensional/Two-Dimensional p-n Heterojunction for Efficient Hydrogen Evolution

Graphdiyne (GDY), an allotrope of carbon, has been of great concern. Conventionally, it has been synthesized by growing on copper foils. In this work, CuI was used as a catalytic material for the synthesis of GDY, which was found to be more favorable for the synthesis. The GDY coupled with Co3O4 formed a zero-dimensional (0D)/twodimensional (2D) p-n heterojunction. A composite catalyst (GO-15) exhibited a strong hydrogen evolution activity that reached 2336.6 mu mol g(-1) h(-1), which is 8.6 and 3.8 times higher than those of GDY and Co3O4. The strong catalytic activity of GO-15 can be ascribed to the fact that the coexistence of Co2+/Co3+ and strong internal electric field in the GO-15 promoted charge separation and diversion. Meanwhile, the 0D/2D structure brought more active sites, and eosin Y (EY) can offer electrons for the GO-15 because of the energy-level difference. In addition, the effective charge-transfer capability of GO-15 was demonstrated in both optical and electrochemical performance tests. This research could provide a pathway for the synthesis and application of GDY and the proper construction of heterojunctions.

Automated summary

Graphdiyne (GDY), an allotrope of carbon, has been successfully synthesized using CuI as a catalytic material, forming a heterojunction with Co3O4. The composite catalyst GO-15 exhibited significantly enhanced hydrogen evolution activity, attributed to factors like Co2+/Co3+ coexistence, internal electric field promotion of charge separation and diversion, increased active sites from the 0D/2D structure, and electron donation from eosin Y.