Multi-interface synergistic photocatalytic 2D/0D/2D TiO2/Pd/Ti3C2 heterojunctions for boosting hydrogen production.

Constructing a multi-interface synergistic catalytic system represents an effective strategy for developing highly efficient photocatalysts; however, the challenge lies in fabricating ideal heterojunctions that can fully harness the multiple synergistic effects of the components. In this study, a series of TiO2/Pd/Ti3C2 nanocomposite photocatalysts with 2D/0D/2D heterojunctions were successfully fabricated through a combination of photoreduction and electrostatic self-assembly techniques by varying the mass ratios. Under irradiation from a 300 W xenon lamp, the as-constructed TiO2/3% Pd/1% Ti3C2 heterojunction photocatalyst exhibited a significantly enhanced H2 evolution rate of 21.60 mmol h-1 g-1, which was approximately 135-fold and 25.4-fold higher than those of pristine TiO2 nanosheets (NSs) and TiO2/1% Ti3C2, respectively. Electrochemical impedance spectroscopy, photoluminescence spectroscopy, and electron spin resonance analysis collectively revealed that the enhanced photocatalytic performance can be attributed to the formation of a synergistic catalytic interface among the TiO2 NSs, highly active Pd NPs, and monolayer Ti3C2 nanosheets. This interface facilitated efficient charge separation, shortened the charge transfer pathways, and enhanced the generation of reactive oxygen species. This study presents a promising strategy for improving catalytic performance through multi-interface synergy and offers a preliminary investigation into the underlying synergistic mechanisms using multiple characterization techniques.