Binary Type-II Heterojunction K(7)HNb(6)O(19)/g-C(3)N(4): An Effective Photocatalyst for Hydrogen Evolution without a Co-Catalyst

The binary type-II heterojunction photocatalyst containing g-C(3)N(4) and polyoxoniobate (PONb, K(7)HNb(6)O(19)) with excellent H(2) production activity was synthesized by decorating via a facile hydrothermal method for the first time. The as-fabricated Nb–CN-0.4 composite displayed a maximum hydrogen evolution rate of 359.89 µmol g(−1) h(−1) without a co-catalyst under the irradiation of a 300 W Xenon Lamp, which is the highest among those of the binary PONb-based photocatalytic materials reported. The photophysical and photochemistry analyses indicated that the hydrogen evolution performance could be attributed to the formation of a type-II heterojunction, which could not only accelerate the transfer of photoinduced interfacial charges, but also effectively inhibit the recombination of electrons and holes. This work could provide a useful reference to develop an inexpensive and efficient photocatalytic system based on PONb towards H(2) production.