Nanotechnology & Catalysis Research Centre (NANOCAT), Level 3 Block A, IPS Building, Institute for Advanced Studies, Universiti Malaya, 50603, Kuala Lumpur, Malaysia.
Industrial Biotechnology Research Center, SIRIM Berhad, 1, Persiaran Dato' Menteri, Section 2, 40700, Shah Alam, Selangor, Malaysia.
Chemosphere. 2022 Dec;308(Pt 1):136219. doi: 10.1016/j.chemosphere.2022.136219. Epub 2022 Aug 27.
Tetracycline (TC) antibiotic removal from water bodies is important to provide clean water and sanitation. Mesoporous graphitic carbon nitride (GCN) photocatalyst derived from three different types of precursors manages to remove TC effectively under visible light irradiation. Among urea, thiourea, and melamine precursors, melamine-prepared GCN (MGCN) via thermal polymerization has the highest efficiency to photodegrade tetracycline (TC) antibiotics up to 99.5% (0.0122 min) within 240 min. The COD for TC removal by using MGCN was up to 77.5% after 240 min of degradation. This is due to the slow charge recombination and rapid charge carrier migration. The MGCN encounters different properties such as high crystallinity, dense structure allowing fast charges migration, and nitrogen vacancies that create a defect state that suppresses charge recombination. It was found that the conduction band (CB) of MGCN was located at a more negative position (E = -0.33 V) than (O/O) and the valence band (VB) was placed at a more positive position (E = 2.30 V) than (HO/OH), which allows generation of both radicals for photodegradation. Based on the cell viability test, the photodegraded TC in the water how non-toxicity toward Balb/c 3T3 cells after being irradiated (λ > 420 nm) for 240 min under visible light. The MGCN prepared in this study demonstrated the highest effectiveness and recyclable photocatalyst for the removal of TC among all GCNs.
从水体中去除四环素（TC）抗生素对于提供清洁水和卫生设施非常重要。 三种不同前体制备的介孔石墨相氮化碳（GCN）光催化剂在可见光照射下能够有效地去除 TC。 在尿素、硫脲和三聚氰胺前体中，通过热聚合制备的三聚氰胺制备的 GCN（MGCN）具有最高的效率，可在 240 分钟内将四环素（TC）抗生素光降解高达 99.5%（0.0122 分钟）。 使用 MGCN 去除 TC 的 COD 在 240 分钟的降解后达到 77.5%。 这是由于缓慢的电荷复合和快速的电荷载流子迁移。 MGCN 遇到不同的性质，如高结晶度、密集结构允许快速电荷迁移和氮空位，这会产生缺陷态，抑制电荷复合。 发现 MGCN 的导带（CB）位于更负的位置（E = -0.33 V）而不是（O/O），价带（VB）位于更正的位置（E = 2.30 V）而不是（HO/OH），这允许产生用于光降解的两种自由基。 根据细胞活力测试，在可见光下照射 240 分钟后，水中光降解的 TC 对 Balb/c 3T3 细胞没有毒性（λ>420 nm）。 与所有 GCN 相比，本研究中制备的 MGCN 是去除 TC 的最高效和可回收光催化剂。
