Integration of high visible-light-driven ternary dual Z-scheme AgVO3-InVO4/g-C3N4 heterojunction nanocomposite for enhanced uranium (VI) photoreduction separation*=

With deepening application of nuclear power technology, the problem of water ecological environment pollution caused by uranium (U(VI)) is becoming increasingly serious. Photoreduction separation of U(VI) on photo-catalysts is considered as an effective strategy to solve uranium pollution. In this work, a novel ternary dual Z-scheme AgVO3-InVO4/g-C3N4 heterojunction (Z-AIGH) nanocomposite with high surface area (73.45 m2 g- 1, Z-AIGH2) was designed. The batch adsorption experiment in dark environment showed that Z-AIGH2 nano-composite had an excellent U(VI) adsorption performance. As for photocatalytic experiments, Z-AIGH2 exhibited a rapid photocatalytic response for separating U(VI) without any organic sacrifice agents. The U(VI) separation rate on Z-AIGH2 nanocomposite was over 98.7% after only 20.0 min visible light irradiation (T = 298 K, CU(VI) = 10.0 mg L-1, m/V = 0.1 g L-1 and pH = 7.0). Z-AIGH2 nanocomposite also showed good selectivity and cycle stability. The U(VI) removal rate of Z-AIGH2 nanocomposite after fifth cycles was about 96.1% (T = 298 K, CU (VI) = 10.0 mg L-1, m/V = 0.1 g L-1 and pH = 7.0). High photocatalytic activity of Z-AIGH2 for U(VI) was attributed to the construction of ternary dual Z-scheme heterojunction structure and ant nest-like hole structure. Based on above results, Z-AIGH2 nanocomposite had great potential for water environment renovation.

Automated summary

With the increasing application of nuclear power technology, the pollution of water ecological environment caused by uranium (U(VI)) has become a serious issue. A novel ternary dual Z-scheme AgVO3-InVO4/g-C3N4 heterojunction (Z-AIGH) nanocomposite with high surface area was designed for the photoreduction separation of U(VI). The Z-AIGH2 nano-composite exhibited excellent U(VI) adsorption performance in dark environment and rapid photocatalytic response for separating U(VI) under visible light irradiation, without requiring any organic sacrifice agents. The high photocatalytic activity of Z-AIGH2 was attributed to its unique structure. The nanocomposite also showed good selectivity and cycle stability, indicating its great potential for water environment renovation.