Facile preparation of metallic 1T phase molybdenum selenide as cocatalyst coupled with graphitic carbon nitride for enhanced photocatalytic H2 production.

Low-cost, highly active and efficient alternative co-catalysts that can replace precious metals such as Au and Pt are urgently needed for photocatalytic hydrogen evolution reaction (HER). Herein, we show that 1T phase MoSe2 can act as the co-catalyst in the 1T-MoSe2/g-C3N4 composites and we synthesize this composite by a one-step hydrothermal method to promote photocatalytic H2 generation. Our prepared 1T-MoSe2/g-C3N4 composite exhibits highly enhanced photocatalytic H2 production compared to that of g-C3N4 nanosheets (NSs) only. The 7 wt%-1T-MoSe2/g-C3N4 composite presents a considerably improved photocatalytic HER rate (6.95 mmol·h-1·g-1), approximately 90 times greater than that of pure g-C3N4 (0.07 mmol·h-1 g-1). Moreover, under illumination at λ = 370 nm, the apparent quantum efficiency (AQE) of the 7 wt%-1T-MoSe2/g-C3N4 composite reaches 14.0%. Furthermore, the 1T-MoSe2/g-C3N4 composites still maintain outstanding photocatalytic HER stability.