Construction of novel 0D/2D AgI/CAU-17 heterojunction with excellent photocatalytic performance by in situ deposition-precipitation

Dye effluent is a serious threat to water ecosystem and human health, so it is urgent to develop high-efficient and stable semiconductor photocatalysts to solve the water pollution problem. A novel AgI/CAU-17 composite with 0D/2D hierarchical heterostructure was first constructed by growing AgI particles on CAU-17 nanorods via a mild deposition-precipitation procedure. The optimal 50% AgI/CAU-17 composite displayed the greatest pho- todegradation rate of 96.7% for RhB, 81.3% for TC and 50.3% for MO, under the simulated solar-light illumi- nation for 70 min. The corresponding apparent rate constants were 0.04401, 0.02227 and 0.01104 min-1, which were 23.79, 15.25 and 19.73-times higher than those of CAU-17, and 4.94, 1.79 and 6.29-times higher than those of AgI. The improved photodegradation performance could be owing to the following causes: 1) The 0D/2D hierarchical heterostructure endowed AgI/CAU-17 composite with tight interfacial contact, which could supply sufficient channels for the migration of photoinduced carriers; 2) The type II charge migrate pathway facilitated the segregation and migration of photoexcited carriers; 3) The AgI/CAU-17 heterostructures reinforced the light absorption capacity and augmented the specific surface area. In addition, various photocatalytic conditions were researched to imitate the degradation process of RhB in the real aqueous system. The radical capture experiments and EPR test attested that h+ and center dot O2-played an important part in the photodegradation of RhB. This study illustrated the tremendous application potential of AgI/CAU-17 heterojunctions in water purification and pro- vided a simple and reliable idea for the preparation of Bi-MOFs composite photocatalysts.

Automated summary

Dye effluent poses a serious threat to water ecosystem and human health, necessitating the development of efficient semiconductor photocatalysts to tackle water pollution. In this study, a novel 0D/2D hierarchical heterostructure AgI/CAU-17 composite was fabricated, exhibiting significantly enhanced photocatalytic performance for RhB, TC, and MO degradation compared to CAU-17 and AgI alone. The improved performance can be attributed to the tight interfacial contact, type II charge migration pathway, and increased light absorption capacity and specific surface area provided by the AgI/CAU-17 heterostructures. This research demonstrates the great potential of AgI/CAU-17 heterojunctions in water purification and provides a simple and reliable approach for the preparation of Bi-MOFs composite photocatalysts.