Two nickel-added poly(polyoxometalate)s built of Keggin-type {Ni 6 PW 9 } and Anderson-type NiW 6 O 24 via WO 4 /Sb 2 O bridges and Ni-O-W linkages with efficient hydrogen evolution activity.

Two Ni-added poly(polyoxometalate)s built of Keggin-type {Ni 6 PW 9 } and Anderson-type NiW 6 O 24 units via WO 4 /Sb 2 O bridges and Ni-O-W linkages, Na 4 H 8 [Ni(enMe) 2 ][(Sb 2 O) 2 (NiW 6 O 24 )-{Ni 12 O 2 (OH) 4 (enMe) 4 (H 2 O) 3 (WO 4 ) 2 (B-α-PW 9 O 34 ) 2 } 2 ]·39H 2 O (1) and H 9 [Ni(en) 2 (H 2 O)][Ni 0.5 (en) 2 (H 2 O)][Ni-(enMe) 2 (H 2 O)][(Sb 2 O) 2 (NiW 6 O 24 ){Ni 12 O 2 (OH) 4 (en) 2 (enMe) 2 (H 2 O) 3 (WO 4 ) 2 }-{Ni 12 O 2 (OH) 4 (en) 4 (H 2 O) 3 (WO 4 ) 2 }(B-α-PW 9 O 34 ) 4 ]·45H 2 O (2), have been hydrothermally synthesized and characterized, in which the {Ni 12 (WO 4 ) 2 (PW 9 ) 2 } subunit was obtained by the synergistic directing effect of 2 lacunary PW 9 O 34 (PW 9 ) fragments and further linked by a central Anderson-type (Sb 2 O) 2 (NiW 6 O 24 ) bridge. Both compounds represent the first example of Ni-added polyoxometalates (POMs) simultaneously based on Keggin-type and Anderson-type POM components. Photocatalytic studies revealed that 2 can work as an efficient heterogeneous catalyst towards a light-driven H 2 evolution reaction, achieving a hydrogen evolution rate of as high as 19 214 μmol g -1 h -1 (TON = 1500), which is superior to most of the reported POM-based heterogeneous catalysts.