Synthesis of vanadium-pentoxide-supported graphitic carbon nitride heterostructure and studied their hydrogen evolution activity under solar light
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Noble-metal-free co-catalyst supported with a highly active and stable photocatalyst is of considerable importance to realize low cost and scaled up photocatalytic hydrogen evolution. An inorganic–organic two-dimensional (2D)/one-dimensional (1D) graphitic carbon nitride (g-C3N4) nanosheet anchored with a vanadium pentoxide (V2O5) nanoparticle heterojunction photocatalyst (GCN/V2O5-3) with excellent solar-light-driven photocatalytic performance was prepared using a facile thermal decomposition method and used for photocatalytic hydrogen (H2) evolution from concentrated lactic acid aqueous solution. The optimized GCN/V2O5-3 catalyst attained a high initial H2 evolution rate of 2891.53 µmol g−1, which is 2.44 times greater than that of pristine g-C3N4 under simulated solar light irradiation. In addition, the GCN/V2O5-3 catalyst is relatively stable for 5 h H2 evolution reactions, indicating the robustness of the V2O5 co-catalyst. The improved photocatalytic activity of the g-C3N4/V2O5 composites can be ascribed to their large specific surface area. Photoelectrochemical analysis results clearly show that V2O5 co-catalyst captures photoinduced holes from the valance band of the excited g-C3N4 by a Z-scheme mechanism and thus improving the charge separation performance and endorse the H+ reduction to H2. Lastly, the mechanism of photocatalytic H2 evolution of the g-C3N4/V2O5 composite is discussed. Importantly, because of its high stability, easy processing, and low cost, the V2O5 co-catalyst has abundant potential in designing high-performance-semiconductor/organic photocatalysts for large-scale H2 production utilizing renewable energy sources.
This research was supported by the National Research Foundation of Korea (NRF) and funded by the Ministry of Science, ICT, and Future Planning (Grant Number 2017R1A2B1004860). This work was also supported by a National Research Foundation of Korea (NRF) grant funded by the Korea government (No. NRF02017R1A4A1015581).