Tailoring metal/support interaction in 0D TiO₂ NPs/MPs embedded 2D MAX composite with boosted interfacial charge carrier separation for stimulating photocatalytic H₂ production

A novel fabrication of multilayered Ti₃AlC₂ MAX decorated with different sizes TiO₂ to maximize charge carrier separation for stimulating photocatalytic H₂ evolution has been investigated. Using TiO₂ nanoparticles with ultrasonic approach, a good dispersion of TiO₂ over 2D Ti₃AlC₂ nanosheets with proficient charge carrier separation was achieved. Highest H₂ production rate of 9073 μmole g⁻¹ h⁻¹ was obtained over TiO₂ NPs/Ti₃AlC₂ heterojunction, which is 10.9 and 26.4 folds higher than using pristine TiO₂ and Ti₃AlC₂, respectively. This significantly enhanced activity was evidently due to faster charge transfer and separation over highly conductive Ti₃AlC₂ MAX structure. More importantly, when TiO₂ MPs were loaded with Ti₃AlC₂, 9.3 folds lower H₂ yield was attained compared to TiO₂ NPs/Ti₃AlC₂ heterojunction synthesized through ultrasonic approach. This was apparently due to good interaction of TiO₂ NPs with uniform distribution over 2D MAX multilayers to promote interfacial charge transfer. Glycerol, among the sacrificial reagents, gave highest H₂ yield, whereas catalyst loading provides more active sites to boost photoactivity. This work provides a new pathway to use Ti₃AlC₂ MAX as an excellent co-catalyst with large interfacial contact and can be employed as an efficient structured material in energy application.