Interfacial engineering between carbon vacancies modified graphitic carbon nitride and CoAl-LDH formed heterojunctions for improved photocatalytic performance: Degradation pathway, DFT calculations, and mechanism insights

Abstract

The construction of green, low-cost heterojunctions with interfacial interaction is crucial to enhance their photocatalytic performance and broaden their utility in practical applications. Here, we prepared CoAl-LDH/Carbon Nitride with carbon vacancies (Cv-CN) heterojunction by electrostatic self-assembly strategy to explore its photocatalytic properties. 30 wt% CoAl-LDH/70 wt% Cv-CN (CCN-2) exhibited the optimal photocatalytic degradation performance after 120 min of light exposure, with a degradation efficiency of 93.1 %. Fukui function calculations, in conjunction with LC-MS/MS analysis, were employed to explore potential degradation pathways during the photocatalytic degradation of tetracycline. The photocatalytic performance of CoAl-LDH/Cv-CN heterojunction was further analyzed by photocatalytic hydrogen production experiments, and after five hours, the hydrogen production rate of CCN-2 was 2515 µmol/g (Cv-CN: 1554 µmol/g, CoAl-LDH: hardly produced any hydrogen). According to the experimental results and data analysis, an effective charge-carrier separation and transfer pathway is established through the interfacial engineering between CoAl-LDH and Cv-CN forming the heterojunction at the interface of CoAl-LDH and Cv-CN. The heterojunction structure formed by interfacial engineering between CoAl-LDH and Cv-CN enables effective photocatalytic removal of antibiotics and hydrogen production providing new insights into the treatment of aqueous environments and clean energy production.