A visible-light-driven dual Z-scheme CeVO4/g-C3N4/LaNiO3 hierarchical nanostructure photocatalyst for effective removal of organic pollutants

Abstract

The major obstacle to restrict the practical application of photocatalysts is the low separation efficiency of photo-induced charge carriers. To overcome the above problem, a novel ternary CeVO4/g-C3N4/LaNiO3 hierarchical nanostructure photocatalyst with dual Z-scheme heterojunction is designed and fabricated by feat of semiconductor energy levels matching engineering. First, one-dimensional (1D) LaNiO3 nanobelts are fabricated by an electrospinning technique. Second, zero-dimensional (0D) g-C3N4 nanoparticles are fixed on 1D LaNiO3 nanobelts through a direct gas-solid reaction. Finally, 1D CeVO4 needle-like nanorods are fixed on g-C3N4/LaNiO3 hierarchical nanostructures through a hydrothermal method. Following exposure to visible-light irradiation for 180 min, the optimized CeVO4/g-C3N4/LaNiO3 hierarchical nanostructure photocatalyst exhibits the highest photocatalytic degradation rate (87.57%) for tetracycline hydrochloride (TCH). Additionally, under the same conditions, the photocatalyst demonstrates its broad applicability by effectively degrading various organic pollutants, including methylene blue (MB) (60.56%), bisphenol A (BPA) (68.00%), ibuprofen (IBU) (57.56%), cefuroxime sodium (CRO) (77.34%), carbamazepine (CBZ) (59.65%) and ciprofloxacin (CIP) (75.16%). The exceptional photocatalytic performance of the CeVO4/g-C3N4/LaNiO3 hierarchical nanostructure photocatalyst can be attributed to the formation of a dual Z-scheme heterojunction among the 1D CeVO4 needle-like nanorods, 0D g-C3N4 nanoparticles, and 1D LaNiO3 nanobelts. The photocatalyst has a large specific surface area and suitable semiconductor energy band positions, providing the hierarchical nanostructures with numerous surface-active sites, rapid charge transfer ability and small charge recombination rate. The design ideas and preparation method proposed in this work have guiding significance for developing other dual Z-scheme heterojunction photocatalysts.