Construction of CdSe polymorphic junctions with coherent interface for enhanced photoelectrocatalytic hydrogen generation

CdSe with high densities of coherent polymorphic zincblende/wurtzite (ZB/WZ) interfaces were deposited on TiO2 nanorod arrays (NRAs) by electrodeposition and an optimized annealing process. In situ TEM annealing experiments observed the formation of the ZB/WZ polymorphic junctions that resulted from the change of atomic stacking sequence by dislocation movement induced by stoichiometry changes occurring during annealing. The process deforms CdSe4-tetrahedrons in ZB driving the ZB to WZ phase transition. The formation of ZB/WZ coherent polymorphic junctions enhanced the separation and transport of photo-generated electron-hole pairs in CdSe. The CdSe/TiO2 photoanode produced H-2 at a rate of 260.9 mu mol cm(-2) h(-1) under AM 1.5 global sunlight (AM 1.5 G). This is the highest reported value among CdSe-based photoanodes, which indicates the important role of the coherent polymorphic junctions.

Automated summary

CdSe with high densities of coherent polymorphic ZB/WZ interfaces were deposited on TiO2 NRAs by electrodeposition and an optimized annealing process. The formation of ZB/WZ coherent polymorphic junctions enhanced the separation and transport of photo-generated electron-hole pairs in CdSe, leading to the CdSe/TiO2 photoanode producing H-2 at a rate of 260.9 mu mol cm(-2) h(-1) under AM 1.5 G. This highlights the important role of coherent polymorphic junctions in enhancing the performance of CdSe-based photoanodes.