Like TBAP-α, the amorphous TBAP material also showed better activity when tested at pH 7; HER increased to 156 µmol g -1 h -1 , (SI, Figure ), which is consistent with an increased driving-force for ascorbic acid oxidation as discussed above. This rate for amorphous TBAP is still 20-times lower than that of crystalline material under equivalent conditions (3108 µmol g - 1 h -1 ), again suggesting that crystallinity and the packing of TBAP units is the dominant factor in the photocatalytic activity of this systems.