Fabrication of S-scheme graphdiyne (g-CnH2n-2)/carbon-nitrogen vacancies hollow Ni–Fe prussian blue analogues heterojunction for boosting wide spectrum photocatalytic hydrogen evolution

Abstract

Efficient photocatalytic hydrogen evolution can be achieved by adjusting the morphology and constructing suitable heterojunction. In this work, an 2D/3D S-scheme graphdiyne (g-C_nH_2n-2)/carbon-nitrogen vacancies hollow Ni–Fe prussian blue analogues (Ni–Fe–CN PBA) heterojunction (GNF-CN) was prepared for photocatalytic hydrogen evolution. Ni–Fe–CN PBA were prepared by chemical etching and high temperature calcination. The hollow structure can realize multiple reflections of incident light and effectively improve the light utilization efficiency. The CN vacancy changes the band structure of Ni–Fe PBA and enhances its light absorption capacity. Graphdiyne nanosheets (GDY) prepared by load ball milling can increase the active site. The key lies in the construction of an S-scheme heterojunction between GDY and Ni–Fe–CN PBA, which effectively consume useless holes and increase the utilization rate of photogenerated electrons. The S-scheme electron transfer path are proved by DFT calculation, work function and in situ XPS. The GNF–CN–20 showed excellent photocatalytic hydrogen evolution activity (3755.02 μmol h⁻¹ g⁻¹) and photostability compared with GDY (1116.54 μmol h⁻¹ g⁻¹). The present study introduces a novel approach for the construction of an S-scheme heterojunction based on GDY and PBA, enabling wide‐spectrum‐responsive photocatalytic hydrogen evolution.