Selective photothermal reduction of CO2 to CH4 via the synergistic effect of Ni-nanoparticle@NiO-nanosheet/V2C-MXene catalyst

Photothermal catalytic carbon dioxide (CO 2 ) reduction has attracted increasing research attention as a promising method for recycling CO 2 and producing renewable energy. However, it remains a challenge in the improvement of catalytic activity with regulated product selectivity in view of practical applications. Herein, we develop the two-dimensional layered V 2 C MXene (VC) supported Ni nanoparticle and NiO nanosheet (Ni@NiO/VC) composite as an efficient catalyst for selective photothermal reduction of CO 2 to CH 4 . The optimal 0.8Ni@NiO/VC catalyst exhibits 48.1 % CO 2 conversion with an evolution rate of 33.2 mmol/g cat /h and 99.2 % selectivity for CH 4 production under a 300 W full-arc xenon lamp irradiation. Moreover, a long-term cyclic photothermal CO 2 reduction reaction demonstrates the excellent stability of 0.8Ni@NiO/VC. The enhanced photothermal CO 2 reduction activity with a high CH 4 selectivity could be attributed to the large specific surface area and excellent photothermal effect of V 2 C MXene, and the synergistic effect of Ni and NiO on adsorption/activation of H 2 and CO 2 molecules. This work provides a feasible strategy for the construction of efficient photothermal CO 2 reduction catalyst by properly incorporating transition metal nanoparticles and metal oxide with a suitable MXene.