Induced dipole moments in amorphous ZnCdS catalysts facilitate photocatalytic H2 evolution

Amorphous semiconductors without perfect crystalline lattice structures are usually considered to be unfavorable for photocatalysis due to the presence of enriched trap states and defects. Here we demonstrate that breaking long-range atomic order in an amorphous ZnCdS photocatalyst can induce dipole moments and generate strong electric fields within the particles which facilitates charge separation and transfer. Loading 1 wt.% of low-cost Co-MoS x cocatalysts to the ZnCdS material increases the H 2 evolution rate to 70.13 mmol g −1 h −1 , which is over 5 times higher than its crystalline counterpart and is stable over the long-term up to 160 h. A flexible 20 cm × 20 cm Co-MoS x /ZnCdS film is prepared by a facile blade-coating technique and can generate numerous observable H 2 bubbles under natural sunlight, exhibiting potential for scale-up solar H 2 production. The rapid recombination of photogenerated charge carriers is a key challenge for photocatalytic hydrogen production. Here, the authors report an amorphous ZnCdS to break the symmetry of atom arrangement that induces strong dipole fields, thus providing extra driving forces for charge separation.