Phosphating 2D CoAl LDH anchored on 3D self-assembled NiTiO3 hollow rod for efficient hydrogen evolution
Two photo-active materials with opposite surface potential, NiTiO3 of negative potential and CoAl LDH of positive potential, are rationally integrated into a combinant of two-dimensional (2D) active plane phosphated-CoAl LDH with rich active sites and three-dimensional (3D) hollow NiTiO3 rods with more negative zeta potential. The delicate architecture can efficiently accelerate the separation and migration of photo-excited electrons, make surface potential become more negative, enhance thermodynamic H2 evolution reaction, and offer rich active planes for photo-catalytic redox reactions. Based on these highlighted photo-catalytic benefits, the optimal composite exhibits more prominent photo-catalytic hydrogen evolution performance compared with alone NiTiO3 or CoAl LDH materials under visible irradiation. In detail, the stereoscopic catalyst constructed by phosphating CoAl LDH layers anchored on NiTiO3 hollow rods exhibits a hydrogen evolution activity about 594 umol∙5h-1 which is 11.6 times and 14.8 times that of alone CoAl LDH (51 umol∙5h-1) and NiTiO3 (40 umol∙5h-1) respectively. And the density functional theory results reveal the good conductivity which is beneficial for charge migration for the hybrid sample. The deeper characterization study results such as TEM, SEM, XPS, XRD, UV-vis DRS, Transient photocurrent and FTIR etc. have been well researched and the results of which are in good agreement with each other.