Intercalation Effect in NiAl-layered Double Hydroxide Nanosheets for CO2 Reduction Under Visible Light

Photocatalytic reduction of CO2(CO2PR) to valuable solar fuels is considered as a promising route to the amelioration of fossil fuel conundrum and the mitigation of greenhouse gases. Although progress has been made to enhance CO2PR performance, the available method that can promote the selectivity of CO2PR products remains to be a challenge. In this work, we synthesized NO3- or CO32- intercalated NiAl-layered double hydroxide(NiAl-LDH) photocatalysts and investigated the performance of CO2PR in the presence of an electron donor and a photosensitizer. Compared with Ni2Al-CO32-, Ni2Al-NO3- exhibited superior catalytic performance in the CO2PR, and the resulted selectivity of CH4 in Ni2Al-NO3-(6.1%) was 12.2 times that of Ni2Al-CO32-(0.5%) under visible light irradiation. X-Ray absorption fine structure(XAFS) result reveals a relative abundance of defects in Ni2Al-NO3-, which played as active sites and promoted charge transfer in CO2PR for the efficient CH4 evolution.