Visible light driven CO₂ photocatalytic reduction by Coporphyrin coupled MgAl layered double hydroxide composite

抄録

MgAl layered double hydroxide (LDH), with the advantages of low cost and wide employment in commercial applications, has been regarded as the promising catalyst for CO₂ photocatalytic conversion into fuels. To improve the visible light absorption and electron separation efficiency of MgAl LDH, metalloporphyrin (Co-TCPP) was used for the surface modification of MgAl LDH to prepare the noble-metal-free nanocomposite (Co-TCPP@LDH). The Co-TCPP@LDH composite exhibits obviously increased photocatalytic activity under visible light compared with pure MgAl LDH. Experiment results show that 20%Co-TCPP@LDH exhibits highest photocatalytic activity with CO yield of 0.40 umolg⁻¹_cat, which is about 4.1 times and 3.3 times than these of MgAl LDH and Co-TCPP. The excellent visible light absorption of porphyrin molecules can effectively widen the light absorption edge to low energy region (600-800 nm). The intramolecular heterogeneous interface and the highly dispersed cobalt metal sites can facilitate charge separation.