Up–conversion and Landau damping effect of Ni1–xNdx(OH)2/Ti3C2 to improve the selectivity of thermal coupled photocatalytic reduction of CO2

Photocatalysis is currently used to enhance CO2 conversion, while improving selectivity is challenging. Herein, Ni1–xNdx(OH)2/Ti3C2 consisting of Nd3+–doped in β–Ni(OH)2 and Ti3C2-MXene was prepared for the selective reduction of CO2 to CO by thermal coupled photocatalytic. The effect of the introduction of the up–conversion effect is (1) to increase the concentration of photogenerated electrons and (2) to increase the catalyst surface temperature. The increased concentration of photogenerated electrons leads to an enhanced Landau damping effect, thus the number of high-energy hot electrons supplementing the Ti3C2 increases. The valence band upward shift reduces the ability of Ni1–xNdx(OH)2/Ti3C2 to dissociate H2. The increased surface temperature of the catalyst and the reduced dissociation of H2 facilitate the thermal coupled photocatalytic reduction of CO2 to CO. A maximum CO yield of 532.9 μmol·gcat.−1·h−1 and CO selectivity of 82.5% was realized on the Ni0.56Nd0.01(OH)2/Ti3C2.