Dual-selenide heterojunctions of ZnSe/Bi2Se3 enhance its photocatalytic performance

Abstract

The removal of antibiotics such as ciprofloxacin (CIP) from wastewater is crucial for protecting the ecological environment. For this purpose, a highly efficient photocatalyst for the degradation of antibiotics is required. Herein, a dual-metal selenide (ZnSe/Bi2Se3) heterojunction was constructed by a facile hydrothermal strategy, and energy bands and heterostructures were also regulated for photocatalytic degradation. The synergistic integration of the heterojunction of dual metal selenide effectively modulates the band structure (narrowed bandgap from 2.55 to 1.33 eV) and optimizes charge carrier separation. The optimal material exhibits a remarkable CIP degradation efficiency of 96.1% within 60 min, with a kinetic rate constant (0.0389 min−1), much higher than that of Bi2Se3 (78.6%) and ZnSe (70.1%). This work establishes a dual-selenide modulation strategy for performance optimization of photocatalytic degradation, which provides insights into the design of dual-selenide heterojunctional photocatalysts for the efficient degradation of antibiotics and organic pollutants.