Synthesis and highly efficient photocatalysis applications of CdS QDs and Au NPs Co-modified KTaO₃ perovskite cubes

Perovskite structure has attracted interest for the past few years due to its prospects in photocatalysis. The exploration of efficient perovskite photocatalysts still receives much attention in the field of chemistry and materials science. Herein, KTaO3 cubes are first prepared by hydrothermal synthesis, then Au nanoparticles (NPs) are loaded on the cubes by photodeposition, and finally, CdS quantum dots (QDs) are modified on Au/KTaO3 cubes using an in situ growth method, and eventually tantalum-based photocatalysts in a ternary system are successfully prepared. The fabricated CdS/Au/KTaO3 reveals photocatalytic properties in hydrogen evolution and degradation of dyes. In particular, under the same conditions, the photocatalytic hydrogen evolution rate of the optimized 13%CdS/1.3%Au/KTaO3 (13% and 1.3% are the contents of CdS and Au in the composite photocatalyst, respectively) is 2.892 mmol g(-1) h(-1). Compared to those of bare KTaO3 and CdS, it is approximately 107-fold and 8.5-fold enhanced, respectively. And the sizes of CdS and Au in the photocatalyst are 4.21 and 15.07 nm. The increased photoactivity of the composite can be ascribed to the synergistic effect of several factors, such as: the Au NPs' surface plasma resonance (SPR) impact improves the production of hot electrons and the ability of KTaO3 to capture light; effective integration between CdS QDs and KTaO3 cubes forms a heterojunction and expands the absorption range of KTaO3 in the visible light spectrum, improving the utilization rate of visible light effectively. Hence, a co-modification strategy has been proposed for endowing KTaO3 perovskites with new structures and different functions, and it is expected to become a general strategy to find an illuminating strategy for achieving improvements and enhancements in the photocatalytic field.