▎ 摘　　要

NOVELTY - Preparing composite catalyst for photocatalytic reduction of carbon dioxide comprises: (a1) providing a porous anodic alumina (PAA) as aluminum substrate, prepared by pre-treatment involving annealing, and electro-polishing; (a2) anodization to form thin layer of aluminum on the substrate as porous anodic alumina films (PAA/Al/PAA); (a3) impregnation of reduced graphene oxide on porous anodic alumina films (PAA/Al/PAA) at elevated temperature to form reduced graphene oxide porous anodic alumina (RGO)/PAA/Al/PAA as substrate; (a4) deposition of cadmium sulfide ions on substrate of step (a3) by reacting cadmium nitrate with sodium sulfide to form adherent film; (a5) cationic and anionic adsorption cycle is followed with drying process is cycle is repeated for 10 times to obtain a homogenous and well adherent film. USE - The process is useful for preparing composite catalyst which is used for photocatalytic reduction of carbon dioxide. ADVANTAGE - The process: does not use any toxic solvents like dimethyl sulfoxide during synthesis of cadmium sulfide; is performed on large scale with a series of photocatalytic cells and hence establishes its applicability for large scale use; and increases the mechanical strength and electrical conductivity of the substrate. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) composite catalyst for photocatalytic reduction of carbon dioxide comprising cadmium sulfide layer/s deposited on the surface of the reduced graphene oxide which is impregnated on the porous anodic alumina as substrate; (2) photochemical cell for photocatalytic reduction of carbon dioxide comprising end plate of acrylic sheet of and the middle plate is with a cavity, inlet and outlet is provided on two opposite ends of middle plate , the top plate has got a window where in quartz plate of is mounted which is as shown in figure 1 of the specification where exposed active area of the catalyst/reactor is as shown in figure 1 of the specification, and each photocatalytic cell is loaded with film catalyst consisting of RGO/cadmium sulfide nanorod catalyst; and (3) continuous photochemical reduction of carbon dioxide comprising passing moist carbon dioxide to the reactor after introduction of carbon dioxide from cylinder to water bubbler saturator, reactions are carried out using sun as the source of energy, series of photocatalytic cells are arranged in a series, compound parabola is used a line focus concentrator, samples are collected continuously using a gas sampling tube, analysis using gas chromatography technique using thermal conductivity detector and flame ionization detector.