Developing photocatalysts with effective charge separation and fast surface reaction kinetics is crucial to realizing efficient photocatalytic water splitting. In this study, we report a strongly coupled two-dimensional-ternary-heterostructured photocatalyst by sequentially introducing reduced graphene oxide (rGO) and NiFe-layered double hydroxide (NiFe-LDH) on the surface of lanthanum titanate (LTO) via a facile hydrothermal and electrostatic self-assembly methodology, respectively. The synthesized 2D-rGO/LTO/NiFe-LDH photocatalyst showed remarkable photocatalytic H2 evolution activity under simulated light irradiation, even without expensive Pt cocatalyst. The enhancement of photocatalytic activity could be attributed to the efficient interfacial charge transfer at the rGO/LTO heterojunction interface, and the enhanced hole (h+) trapping ability of NiFe-LDH cocatalyst at the LTO/NiFe-LDH interface, respectively. These attributes could effectively enlarge the life time of photo-generated electron-hole pairs, and increase the electron density for hydrogen production. The optimal rGO/LTO/NiFe-LDH nanocomposite remain sustained even after four successive experimental runs, without apparent change in the H2 evolution rate. The present work elucidates a new strategy to maximize the efficiency via synergetic effect of incorporating rGO and NiFe-LDH as dual cocatalysts, and shows a feasible strategy of using earth-abundant materials as cocatalysts to enhance the overall photocatalytic water splitting reactions.
Bibliographical noteFunding Information:
This work was supported by grants of the National Research Foundation (NRF) of Korea , funded by the Korean Government (Nos. 2017R1A2A1A05022387 , 2011-0030255 , and 2012R1A3A2026417 ). The authors appreciate Dr. Filipe Marques Mota for the fruitful discussion for the summary of the manuscript.
All Science Journal Classification (ASJC) codes
- Environmental Science(all)
- Process Chemistry and Technology