MXene Derived Ti3C2–TiO2 Coupled NiCo LDH: A 2D/3D Interfacial Engineered S-Scheme Heterojunction for Enhanced Photocatalytic H2O2 and H2 Production

Superior S-scheme heterojunction based photocatalysis is in the forefront as a sustainable approach for quenching the current energy thirst owing to its augmented charge pair separation kinetics and preserved redox ability. Herein, we fabricated an S-scheme/Schottky triphase heterojunction of Ti3C2 MXene derived TiO2 modified NiCo LDH by a two-step hydrothermal process. The structural and morphological analyses evidenced that the 3D NiCo LDH nanoflower fruitfully incorporated on the 2D Ti3C2@TiO2 nanosheet to form a Ti3C2@TiO2/NiCo LDH 2D/3D engineered interface. The Ti3C2@TiO2/NiCo LDH (20 wt %) nanohybrid exhibited superior photocatalytic H2O2 and H2 production rates compared to the NiCo LDH and Ti3C2@TiO2 neat counterparts. The enhanced performance was credited to the combined influence of the S-scheme and Schottky junctions, effectively lowering charge transfer resistance and enhancing the separation ability, as supported by PL, EIS, and TPC analyses. The metallic character and high conductivity of Ti3C2 provide more active sites through the Schottky junction for photocatalytic reaction. Moreover, due to the open void nanoflower structure of NiCo LDH, the diffusion distance was shortened, mass transport accelerated, and light reflection and scattering were enhanced. The S-scheme charge transfer mechanism was validated by scavenging and EPR analysis. This research shows in-depth understanding to design S-scheme/Schottky heterojunctions for solar to chemical energy conversion.