Two 2D layered Co-modified Anderson-type polyoxometalate-based highly efficient photocatalysts for CO2 reduction

The design of efficient and low-price photocatalysts is an effective way to relieve excessive carbon dioxide emissions and energy dilemma. Polyoxometalates are ideal materials due to their adjustable structures and semiconductor-like properties. Limited by their light absorption capacity, it is a feasible way to construct inorganic-organic composite polyoxometalate-based photocatalysts. Here, two efficient Anderson-type polyoxometalate-based photocatalysts, (C 10 H 9 N 2 )·{[Co(H 2 O) 2 ]·[H 6 CrMo 6 O 24 ]}·4H 2 O ( 1 ), {[Co(H 2 O) 3 ]·[Co(DAPSC)] 2 ·[H 6 CrMo 6 O 24 ] 2 }·11H 2 O ( 2 ) [2,6-diacetylpyridine bis(semicarbazone), abbr. DAPSC], were prepared by hydrothermal synthesis method. The structural analysis indicates that compounds 1 and 2 share similarities: {CrMo 6 } units were linked by cobalt ions to form two-dimensional (2D) frameworks. The addition of Co ions provided catalytic active center for the catalyst, compounds 1 and 2 exhibited promising yield into CO, as high as 3061.6 μ mol g −1 ·h −1 and 9309.8 μ mol g −1 ·h −1 , respectively. Due to their excellent properties, Anderson-type POMs can be used as the basic units of photocatalysts. At the same time, four cycling tests prove the stability of compound 2 under a long reaction time.