Synthesis of Novel Ternary Dual Z-scheme AgBr/LaNiO(3)/g-C(3)N(4) Composite with Boosted Visible-Light Photodegradation of Norfloxacin

Promoting the separation of photogenerated charges and enhanced optical absorption capacity is the main means to modify photocatalytic capacities to advance semiconductor photocatalyst applications. For the first time, a novel ternary photocatalyst for dual Z-scheme system AgBr/LaNiO(3)/g-C(3)N(4) (ALG) was prepared via a modest ultrasound-assisted hydrothermal method. The results indicated that LaNiO(3) nanoballs and AgBr nanoparticles were successfully grown on the surface of g-C(3)N(4) nanosheets. A dual Z-scheme photocatalytic reaction system could be constructed based on the energy band matching within AgBr, LaNiO(3) and g-C(3)N(4). Metallic Ag during the photocatalytic reaction process acted as the active electrons transfer center to enhance the photocatalytic charge pairs separation. The chemical composition of ALG was optimized and composites with 3% AgBr, 30% LaNiO(3) and 100% g-C(3)N(4) which was noted as 3-ALG displayed the best photocatalytic performance. A total of 92% of norfloxacin (NOR) was photodegraded within two hours over ALG and the photodegradation rate remained >90% after six cycles. The main active species during the degradation course were photogenerated holes, superoxide radical anion and hydroxyl radical. A possible mechanism was proposed based on the synergetic effects within AgBr, LaNiO(3) and g-C(3)N(4). This work would offer a credible theoretical basis for the application of dual Z-scheme photocatalysts in environment restoration.