MnFe2 O4 Nanocrystals Wrapped in a Porous Organic Polymer: A Designed Architecture for Water-Splitting Photocatalysis.

A novel MnFe2 O4 -porous organic polymer (POP) nanocomposite was synthesized by a facile hydrothermal method and using the highly cross-linked N-rich benzene-benzylamine POP. The nanocomposite presented highly efficient photocatalytic performance in the hydrogen evolution reaction (HER) from pure water without addition of any sacrificial agent under one AM 1.5 G sunlight illumination. A photocatalytic activity of 6.12 mmol h-1  g-1 was achieved in the absence of any noble metal cocatalyst, which is the highest H2 production rate reported for nonprecious metal catalysts. The photocatalytic performance of MnFe2 O4 -POP could be attributed to the intrinsic synergistic effects of manganese ferrite (MnFe2 O4 ) nanoclusters interacting with the nitrogen dopant POP with a unique mesoporous nanoarchitecture and spatially confined growth of MnFe2 O4 in the interconnected POP network, leading to high visible-light absorption with fast electron transport.