NiAl‐LDH In‐Situ Derived Ni2P and ZnCdS Nanoparticles Ingeniously Constructed S‐Scheme Heterojunction for Photocatalytic Hydrogen Evolution

Abstract

AbstractSurface modification of photocatalytic materials is a good choice for improving semiconductor activity. Simple surface modification strategy and abundant active site construction are the key factors to improve photocatalytic activity. Take NiAl‐LDH as the matrix, perform partial phosphating, and use the spatial confinement effect to generate highly dispersed Ni2P. Ni2P does not exist independently but on the 3D NiAl‐LDH's surface. The introduction of NiAl‐LDH‐P can improve the utilization of Zn0.5Cd0.5S on solar energy and speed up the transfer rate of photogenerated carriers. Ni2P makes the active sites of phosphide more abundant, and the unique electron distribution of phosphide is conducive to photon capture, thus accelerating the hydrogen precipitation rate in the composite photocatalyst. Partial phosphating retains the 3D framework of hydrotalcite. The well‐dispersed 0D to 3D S‐scheme heterojunction hybrid material is composed of three‐dimensional nano‐flowers and tiny nano‐particles alternately formed by countless nano‐sheets. The multi‐dimensional structured composite photocatalyst has abundant active sites, large specific surface area, and strong proton adsorption capacity, thus exhibiting more excellent photocatalytic hydrogen evolution performance. The maximum hydrogen production of the composite photocatalyst under 5 W LED simulated visible light for 5 h can reach 1982.43 μmol (39.64 mmol g−1 h−1) and the apparent quantum efficiency reached 6.22 % at 475 nm. The construction of the Zn0.5Cd0.5S/NiAl‐LDH‐P S‐scheme heterojunction changes the hydrogen evolution site from Zn0.5Cd0.5S to Ni2P, so that the conduction band position of the composite photocatalyst becomes higher, the reduction ability is enhanced, and the hydrogen evolution The site changed from Zn0.5Cd0.5S to Ni2P, which is more conducive to the generation of hydrogen, thereby improving the activity and stability of hydrogen production. The space design of 0D and 3D provides new thinking for the design of the closely contacted S‐scheme heterojunction photocatalytic. The application of surface modification strategies and the construction of abundant active sites point out the direction for further improving the composite photocatalytic activity.