Efficient charge separation and transfer in a one-dimensional carbon nanotube/tungsten oxide p–n heterojunction composite for solar energy conversion

Abstract

Efficient and cost-effective photocatalysts for solar energy conversion represent a rapidly advancing and compelling area of research. In our study, we employed theoretical calculations to design a novel composite material consisting of a one-dimensional (1D) carbon nanotube (CNT) and tungsten oxide (W₁₈O₄₉) p–n heterojunction. This composite material was successfully synthesized using a straightforward solvothermal method, and we thoroughly investigated the charge separation and transfer mechanism. Our findings revealed that the composite material exhibited a superior photocurrent response. Notably, the CNTs/W₁₈O₄₉-2 sample demonstrated a significantly higher photocurrent under both AM 1.5G and infrared light irradiation, outperforming the individual components under AM 1.5G by a substantial factor of 30. This remarkable enhancement in performance can be attributed to the efficient charge separation and transfer facilitated by the built-in electric field created at the interface through the p–n heterojunction. Our study introduces a pioneering integration of CNTs and 1D tungsten oxide, resulting in a composite structure with a p–n heterojunction—a concept that has not been extensively explored previously. The results confirmed the formation of this unique one-dimensional structure and a p–n heterojunction, which has outstanding properties for various applications. These findings provide a robust foundation for the design of photocatalytic interfaces and offer a fresh approach to the development of high-performance photocatalysts.