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 CdO quantum dots (QDs)/CdS intimate heterojunction. We developed a plasma-assisted method to prepare CdO-QDs/CdS heterojunction where CdS(200) and CdO(111) are tilted with a dihedral angel of 159° 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. • CdO quantum dots was generated on CdS via plasma treatment • Semi-coherent interface and quantum size facilitate carrier transfer to surface • CdO-QDs/CdS promotes the photocatalytic bio-CO evolution The construction of heterojunction is effective for spatial separation of photo-induced carriers and is widely used in photocatalysis. However, owing to the poor lattice mismatch at the interface, the loose interface and the abundant of dangling bond generally constrain the interparticle migration of photocarriers. Here, we report the surface oxidative reconstruction of CdS to form CdO quantum dots (QDs)/CdS intimate heterojunction where CdS(200) and CdO(111) are tilted with a dihedral angel of 159° 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. A wide range of biomass resources, even polysaccharides can be converted into CO. The surface oxidative reconstruction of CdS to form CdO quantum dots (QDs)/CdS intimate heterojunction was prepared. The CdO-QDs/CdS heterojunction where CdS(200) and CdO(111) are tilted with a dihedral angel of 159° 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.