Synthesis of ZnO/Carbon Nanotube Composites for Enhanced Photocatalytic Performance and Its Mechanism Study

ABSTRACT In this paper, zinc oxide (ZnO) nanotubes were synthesized via an anodic oxidation method, and ZnO/carbon nanotube (CNT) composites (ZnCNTs) were further fabricated through a hydrothermal method. The ZnCNT composites exhibited enhanced photodegradation efficiency for Rhodamine B (RhB) under simulated sunlight irradiation, with ZnCNT‐5.7 (5.7 wt% CNTs) achieving 98.4% RhB degradation within 7.5 min. The apparent reaction rate constant ( k = 0.433 min− 1 ) was 4.84‐ and 3.46‐folds higher than those of pristine ZnO and ZnCNT‐1 (1 wt% CNTs), respectively. This superior photocatalytic performance originated from extended visible light absorption and improved charge carrier separation efficiency, which facilitated the utilization of photogenerated electrons (e − ) and holes (h + ). Radical trapping experiments confirmed that superoxide radicals (·O 2 − ) and hydroxyl radicals (·OH) were the dominant active species responsible for RhB degradation. This work provides a feasible strategy for designing efficient photocatalysts for dye‐contaminated water treatment.