Photocatalytic H2 generation via CoP quantum-dot-modified g-C3N4 synthesized by electroless plating

Photocatalytic water splitting is a promising method for hydrogen production. Numerous efficient photocatalysts have been synthesized and utilized. However, photocatalysts without a noble metal as the co-catalyst have been rarely reported. Herein, a CoP co-catalyst-modified graphitic-C 3 N 4 (g-C 3 N 4 /CoP) is investigated for photocatalytic water splitting to produce H 2 . The g-C 3 N 4 /CoP composite is synthesized in two steps. The first step is related to thermal decomposition, and the second step involves an electroless plating technique. The photocatalytic activity for hydrogen evolution reactions of g-C 3 N 4 is distinctly increased by loading the appropriate amount of CoP quantum dots (QDs). Among the as-synthesized samples, the optimized one (g-C 3 N 4 /CoP-4%) shows exceptional photocatalytic activity as compared with pristine g-C 3 N 4 , generating H 2 at a rate of 936 μ mol g −1 h −1 , even higher than that of g-C 3 N 4 with 4 wt% Pt (665 μmol g −1 h −1 ). The UV-visible and optical absorption behavior confirms that g-C 3 N 4 has an absorption edge at 451 nm, but after being composited with CoP, g-C 3 N 4 /CoP-4% has an absorption edge at 497 nm. Furthermore, photoluminescence and photocurrent measurements confirm that loading CoP QDs to pristine g-C 3 N 4 not only enhances the charge separation, but also improves the transfer of photogenerated e − -h + pairs, thus improving the photocatalytic performance of the catalyst to generate H 2 . This work demonstrates a feasible strategy for the synthesis of highly efficient metal phosphide-loaded g-C 3 N 4 for hydrogen generation. The photocatalytic activity of H 2 generation over g-C 3 N 4 /CoP composites prepared by an electroless plating method is much higher than that over pure g-C 3 N 4 . The composites boosted the separation and migration of photogenerated carriers, resulting in a higher photocatalytic activity.