Interstitially O-doped CdxZn1−xS solid solution derived from chalcogenide molecular clusters for photocatalytic hydrogen evolution

Abstract

Interstitial oxygen dopants (O_i) in sulfide nanocrystals are more conducive to charge carrier separation for improving the photocatalytic hydrogen evolution (PHE) performance than substituted oxygen dopants (O_S). However, oxygen dopants exist dominantly in the form of O_S, rather than O_i, in oxygen-doped sulfides prepared via traditional methods. Herein, an O_i-doped Cd_xZn_1−xS solid solution was facilely synthesized through pyrolyzing a mixture of oxygen-containing zinc sulfide clusters and CdCl₂ salts. At a controlled pyrolysis temperature, the oxygen components inside the cluster were successfully converted into O_i dopants associated with sulfur vacancies. The as-synthesized O_i-doped Cd_xZn_1−xS solid solution exhibits good PHE performance due to its unique energy band structure caused by the two coexistent defects. The synthetic method of using the intrinsic components in molecular clusters to modulate the types of specific dopants in photocatalysts may provide a new synthetic strategy for creating doped photocatalysts with excellent PHE activities.