Enhanced visible-light degradation over N-CD-modified Bi7VO13: the role of interfacial charge transport

Abstract

Antibiotic contamination has become a critical challenge in global water management, and photocatalysis has emerged as a promising strategy to address both environmental and energy issues. Although the novel photocatalyst Bi₇VO₁₃ shows intrinsic potential, its catalytic performance was hindered by high photogenerated charge carrier recombination rates and low quantum efficiency. In this work, Bi₇VO₁₃ was synthesized via a one-step hydrothermal method by simple pH modulation, and nitrogen-doped carbon dots (N-CDs) were incorporated to construct an N-CDs/Bi₇VO₁₃ composite photocatalyst. Under visible-light irradiation, the N-CDs/Bi₇VO₁₃ composite achieved 89.5% degradation of tetracycline hydrochloride (an initial concentration of 10 mg L⁻¹) within 90 minutes, corresponding to a 2.42-fold enhancement in the degradation rate compared to pristine Bi₇VO₁₃. Furthermore, the built-in electric field of the composite was significantly strengthened, indicating that N-CDs act as electron traps to effectively promote photogenerated charge carrier separation. The simultaneous enhancement of light absorption and charge separation efficiency enables a remarkable improvement in the antibiotic degradation performance of N-CDs/Bi₇VO₁₃. Overall, this study offers a rational framework for the design of high-performance photocatalysts and a scientific reference for the future application of photocatalysis, paving the way for addressing the dual challenges of environmental pollution and energy scarcity.