Deactivation and Stabilization Mechanism of Photothermal CO2 Hydrogenation over Black TiO2

Photothermal catalytic reduction of CO2 is a powerful way to promote carbon neutralization goals. However, there are few reports on the deactivation of the photothermal CO2 reduction reaction. Here, we observed an interesting deactivation phenomenon of photothermal CO2 conversion over TiO2–xHx (black TiO2). Despite the presence of a reducing atmosphere of H2, the oxygen vacancy concentration of TiO2–xHx is reduced, resulting in the deactivation of photothermal CO2 reduction. After Ni is modified onto TiO2–xHx, Ni can activate H2 to form Hs, and the oxygen vacancy concentration of Ni/TiO2–xHx may be maintained, thus solving the deactivation problem in photothermal CO2 hydrogenation.