Internal Electric-Field-Driven CoAl-LDH Coupled N-Rich Carbon Nitride of C₃N₅ for Improved Photocatalytic Performance

Abstract

Preparing photocatalysts with excellent performance to degrade organic pollutants in water is still a great challenge. Herein, we prepared CoAl-layered double hydroxide (LDH) coupled N-rich carbon nitride of C 3 N 5 materials to investigate the feasibility of preparing materials for photocatalytic treatment of organic pollutants under natural water bodies. After 120 min of light exposure, the CoAl-LDH/C 3 N 5 (CCN-100) composite showed optimal photocatalytic degradation performance, in which the degradation efficiency reached 94.02% in pure water and 91.85% in Xiangjiang water. Three possible photocatalytic degradation pathways of tetracycline were analyzed by liquid chromatography with tandem mass spectrometry. The toxicity of the intermediates was assessed by toxicity assessment software. The results showed that the toxicity of the intermediates was greatly reduced. We analyzed the formation of the internal electric field and the direction of charge migration in the CoAl-LDH/C 3 N 5 heterojunction by the difference in the work function and the energy band structure of CoAl-LDH and C 3 N 5 . According to various characterization analysis and experimental results, the internal electric field formed between CoAl-LDH and C 3 N 5 accelerates the charge transfer and the rapid separation of photogenerated electron holes thus improving the photocatalytic degradation performance. This study provides new insights into the effective removal of organic pollutants from water through the formation of an internal electric field in CoAl-LDH/C 3 N 5 heterojunction.

C3N5-based nanomaterials and their applications in heterogeneous catalysts, energy harvesting, and environmental remediation

“…In summary, the application of C 3 N 5 and its modified materials for the photocatalytic degradation of pollutants has yielded promising results in recent years, including studies on the degradation of tetracycline (TC), RhB, MB, SMX, and NO. 96,97 This discussion highlights the impressive performance of C 3 N 5 -based materials in photocatalytic degradation applications, solidifying the position of C 3 N 5 as a highly promising material within the C x N y family.…”

Continuous Scavenging of Long-Lived Reactive Radicals for Enhancing the Photocatalytic Reduction Efficiency of Conjugated Polymers

“…Taking P1-E and P1 polymers as examples, the pathways involve O 2 – generation from dissolved O 2 , O 2 – transformation to H 2 O 2 , and further conversion to ·OH. When ROS-consuming contaminants (Tc) were introduced, degradation mechanisms aligned with ROS generation, with P1-E favoring ·OH reactions and P1 favoring ·O 2 – reactions. − After the addition of Tc to the Cr(VI) solution, the timely consumption of long-lived ·O 2 – in the P1 photocatalytic system led to a remarkable 43-fold enhancement in the reduction rate of Cr(VI) (from 0.00309 to 0.13248 min –1 ). However, in the P1-E system dominated by short-lived ·OH, the introduction of Tc only increased the reduction rate of Cr(VI) by a factor of 3 (from 0.00623 to 0.02111 min –1 ).…”