Fabricating structured 2D Ti3AlC2 MAX dispersed TiO2 heterostructure with Ni2P as a cocatalyst for efficient photocatalytic H2 production

Abstract

A novel 2D MAX structure of Ti3AlC2 multilayers dispersed with TiO2/Ni2P heterojunction was designed and fabricated through modified sol-gel method for enhanced photocatalytic hydrogen production. Ni2P cocatalyst coupled 2D Ti3AlC2/TiO2 composite showed enhanced visible light absorption with promoted charge carrier separation. The activity of pristine Ti3AlC2 was obviously increased with the growth of TiO2 NPs and by exfoliating 2D MAX structure into multilayers. 2D Ti3AlC2/TiO2/Ni2P composite exhibited highest H2 production of 13000 μmol g−1 which was 1.29, 3.63 and 3.80 times more than the amount generated by TiO2/Ti3AlC2, TiO2/Ni2P and pristine TiO2, respectively. This enhanced activity was obviously due to good dispersion of TiO2/Ni2P over the Ti3AlC2 multilayers with boosted photoinduced charge carrier separation. Among the sacrificial reagents, glycerol-water mixture gave maximum H2 production due to the presence of more α-hydrogen atoms. More importantly, highest CO2 was evolved using a glycerol-water mixture compared to methanol, confirming both photocatalytic water splitting and photoreforming reactions occur simultaneously. The reaction mechanism to understand the role of each component in the composite catalyst is further discussed. The findings of this work would be helpful in commercial applications of Ti3AlC2 MAX based structured catalysts for H2 production and other sustainable energy systems.