Metal-organic coordination polymers-derived ultra-small MoC nanodot/N-doped carbon combined with CdS: A hollow Z-type catalyst for stable and efficient H2 production/CO2 reduction

Excellent and stable photocatalytic activities are attributed to the construction of hollow Z-type CdS-C/MoC with multi-scattering of incident light. With CdS as electrons enrichment site, the system significantly reduces the accumulation of holes on the VB of CdS component for effectively inhibiting the photocorrosion of CdS. • N-doped C-MoC is obtained via metal-organic coordination polymer-derived strategy. • Hollow N-doped carbon nanoflower with highly dispersed MoC nanodots is prepared. • Special Z-type N-doped C-MoC/CdS can greatly inhibit photo-corrosion of CdS. • CdS-C/MoC exhibits the efficient H 2 evolution that is 4.5-fold as high as that for Pt/CdS. Hollow N-doped carbon nanoflower with highly dispersed MoC nanodot embedded forms a cocatalyst and then CdS nanoparticles are grown to construct CdS-C/MoC hollow Z-type heterostructures for hydrogen production and CO 2 reduction. The optimized CdS-C/MoC (CCM2) heterojunction exhibits an enhanced hydrogen evolution reaction (HER) rate of 13917.7 μmol h -1 g cat -1 that is 4.5-fold as high as that for Pt/CdS with equal load rate via photo-deposition method and highly stabilizes at least 5 cycles (15 h) while HER rate of bare CdS decreases to 38.2% (267.4 μmol h -1 g cat -1 ) at the second time. The apparent quantum efficiency (AQE) of CCM2 achieves 82.35% at λ = 420 nm. Moreover, the CO 2 reduction generation rate of CCM2 is 5.57 μmol h -1 g cat -1 . Photostable and efficient photocatalytic activities are attributed to special Z-type mechanisms where CdS acts as electrons enrichment site to greatly suppress photo-corrosion, and hollow architecture with multi-scattering of incident light. The reduced H adsorption free energy (ΔG H* ) shows the C/MoC co-catalyst contributes to the enhanced hydrogen production. Density functional theory calculations and electron paramagnetic resonance analysis, further validate the direction of electrons transfer in CdS-C/MoC system and special Z-type mechanisms for stable photocatalytic performance.