Plasma-assisted construction of CdO quantum dots/CdS semi-coherent interface for the photocatalytic bio-CO evolution

Heterojunction is promising to promote the spatial charge separation while the poor lattice mismatches and the bulk size of semiconductors constrain the photocarrier separation and migration to the surface. Herein, we report the surface oxidative reconstruction of CdS to form CdOquantumdots (QDs)/CdS intimate heterojunction. Wedeveloped a plasma-assisted method to prepare CdO-QDs/CdS heterojunction where CdS(200) and CdO(111) are tilted with a dihedral angel of 159 degrees to form a semi-coherent interface, maximally reducing the interface dangling bonds. The semi-coherent interface and the quantum size of CdO-QDs efficiently promotes charge separation and migration to the surface, accelerating the photocatalytic bio-CO evolution. With glycerol as feedstock, the CO generation rate over CdO-QDs/CdS reaches 2.37 mmol g(-1.)h(-1), which is 4-fold of that over CdS. The present work reports a new method for the preparation of CdO-QDs/CdS intimate heterojunction and gives insight into tuning lattice coherency to promote photocarrier separation.

Automated summary

This study reports a new method for the preparation of CdO quantum dots/CdS intimate heterojunction through surface oxidative reconstruction of CdS. The semi-coherent interface and quantum size of CdO quantum dots efficiently promote charge separation and migration to the surface, enhancing the photocatalytic CO generation rate.