There is disclosed a method of constructing a layered double hydroxide (LDH) material comprising selected metal ions, and employing metallic vanadium carbide (V.sub.2C) for promoting conductive properties of the LDH material, wherein the layered LDH material is a trimetallic LDH material. The trimetallic LDH material comprises selected Ni.sup.2+, Co.sup.2+, and A.sup.3+ metal ions with its cationic configuration for improving photocatalytic properties of the LDH material, wherein trimetallic nickel-cobalt-aluminium layered double hydroxide (Ni.sub.xCo.sub.yAl.sub.z LDH) and vanadium carbide MXene (V.sub.2C)-based composite is coupled with a graphitic carbon nitride (g-C.sub.3N.sub.4) nanosheet, to form a hybrid-junction photocatalyst. Also disclosed is a layered structure of vanadium carbide (V.sub.2C) MXenes, comprising trimetallic nickel-cobalt-aluminium layered double hydroxide (Ni.sub.xCo.sub.yAl.sub.z LDH) and vanadium carbide MXene (V.sub.2C) coupled with graphitic carbon nitride (g-C.sub.3N.sub.4), forming a Ni.sub.xCo.sub.yAl.sub.z LDH/g-C.sub.3N.sub.4 hybrid-junction photocatalyst.