2D/2D g-C3N4/MgFe MMO nanosheet heterojunctions with enhanced visible-light photocatalytic H2 production

Highlights: • MgFe MMO was employed to construct 2D/2D nanosheet heterojunction with g-C₃N₄. • The existence of MgFe MMO impeded the overgrowth of g-C₃N₄. • The photocatalytic activity of nano-CN/MgFe-30 was 6.64 times than that of g-C₃N₄. • This strategy supported large-scale production of nano-g-C₃N₄ based heterojunction. As an emerging p-conjugated materials, graphitic carbon nitride (g-C₃N₄) has captured worldwide attention due to impending energy crisis and increasingly serious environmental contamination. In this work, the two-dimensional (2D) MgFe mixed metal oxide (MMO) derived from the layered double hydroxides precursor was employed to construct 2D/2D nanosheet heterojunction with g-C₃N₄. The formed CN/MgFe-30 nanosheet heterojunctions exhibited the optimal photocatalytic hydrogen production about 6.64 times (1.26 mmol/g⁻¹·h⁻¹) than that of pure g-C₃N₄ under the visible light irradiation, which were attributed to unique inter-plane 2D/2D structure and excellent synergistic effect between g-C₃N₄ and MgFe MMO. The experiment characterization proved that MgFe MMO nanosheet not only suppressed the overgrowth of g-C₃N₄, resulting in the formation of nanoscale g-C₃N₄, but also facilitated the photoinduced carrier separation and transfer based on 2D/2D CN/MgFe-X nanosheet heterojunctions. This proposed synthesis strategy pave a way to realize the large-scale production of nano-g-C₃N₄ based 2D/2D nanosheet heterojunctions photocatalysts for hydrogen production.