Photocatalytic reduction of CO2 using CdS nanorods on porous anodic alumina support

Highlights: • Commercial grade quality of aluminum foil was used to fabricate uniformly ordered PAA. • A more compassionate method of SILAR was adopted for synthesis on CdS on PAA. • Photocatalytic reduction of CO₂ was carried on flat sheet reactor with mirror reflectors, which proves to be a potential candidate for large scale application. • Enhanced photocatalytic reduction of CO₂ was obtained, when CdS was retained along the pore wall of the support. - Abstract: Solar reduction of CO₂ to valuable chemicals has captured attention of several researchers due to its cumulative effect on reduction of global warming and also as an alternative to fossil fuels. Hexagonally ordered porous anodic alumina (PAA), prepared from commercial aluminium foil, was used as a support for CdS photocatalyst due to its unique honeycomb structure. The CdS nanorods were vertically grown on the PAA template by successive ion layer adsorption reaction (SILAR) method. The photocatalytic reduction of CO₂ by CdS to CH₃OH was investigated using a flat sheet reactor under 10 W LED lamp. A peak CH₃OH formation at 144.5 μmol/g/h with 45.4% of photocatalytic efficiency and 1.97% of CO₂ conversion efficiency in a single pass were obtained.